INTRODUCTION: Small bowel angiodysplasia (AGD) is a common yet diagnostically challenging cause of gastrointestinal (GI) bleeding in older patients, particularly in those receiving anticoagulants. In hemodynamically unstable cases where conventional modalities fail, intraoperative enteroscopy (IOE) remains an important rescue modality.

CASE PRESENTATION: An 85-year-old man receiving apixaban presented with life-threatening melena and hemorrhagic shock (hemoglobin nadir 5.5 g/dL). Esophagogastroduodenoscopy, colonoscopy, and selective mesenteric angiography were all non-diagnostic. Dynamic contrast-enhanced CTA demonstrated active contrast extravasation in the deep ileum. An emergency laparotomy with IOE was performed: a sterile upper GI endoscope was introduced through a mid-intestinal enterotomy and advanced bi-directionally; systematic intraluminal irrigation with warmed saline via a water-jet system restored clear visualization of the small bowel mucosa; and a minute, actively spurting vascular lesion was identified in the deep ileum. A targeted 10-cm segmental resection with primary anastomosis was performed. No gross abnormalities were evident in the resected specimen; however, histopathology confirmed AGD with dilated, tortuous submucosal vessels. No recurrent bleeding was observed over 1 year of follow-up.

CONCLUSIONS: IOE-guided surgery is a definitive diagnostic and therapeutic option in life-threatening small bowel bleeding when standard modalities fail. Early multidisciplinary decision-making and prompt surgical intervention are essential in such high-risk older patients receiving anticoagulation therapy.

INTRODUCTION: Stomal variceal bleeding is a rare but potentially life-threatening complication in patients with gastrointestinal stomas complicated by portal hypertension. Although oxaliplatin-based chemotherapy is widely used for colorectal cancer, it is known to cause sinusoidal obstruction syndrome (SOS), which may result in non-cirrhotic portal hypertension. However, stomal variceal bleeding secondary to oxaliplatin-induced portal hypertension has rarely been reported.

CASE PRESENTATION: A 67-year-old man underwent curative surgery for rectal cancer, followed by 12 courses of oxaliplatin-based chemotherapy for pelvic recurrence. During chemotherapy, progressive anal pain led to the creation of a colostomy. After resumption of chemotherapy, recurrent and refractory stomal bleeding developed following an additional 5 courses. Despite conservative management, including local hemostatic measures and blood transfusions, the bleeding persisted. CT and laboratory examinations revealed splenomegaly, dilatation of the portal and mesenteric veins, and thrombocytopenia without evidence of liver cirrhosis. Based on these findings, portal hypertension caused by oxaliplatin-induced SOS was considered the most likely etiology of the stomal varices. Percutaneous transhepatic obliteration (PTO) was therefore performed and successfully achieved complete hemostasis without recurrence.

CONCLUSIONS: Clinicians should be aware that oxaliplatin-induced portal hypertension can cause stomal variceal bleeding even in the absence of liver cirrhosis. Careful long-term monitoring for portal hypertensive complications is warranted in patients receiving prolonged oxaliplatin-based chemotherapy. Percutaneous transhepatic variceal obliteration represents a safe and effective treatment option for refractory stomal variceal bleeding.

INTRODUCTION: Breast carcinoma with osteoclast-like giant cells (OGCs) is an uncommon morphological finding, and its clinical significance remains unclear. We report a case of synchronous bilateral hormone receptor-positive breast cancer including a small, low-grade carcinoma with OGCs, followed by early distant recurrence after surgery.

CASE PRESENTATION: A 47-year-old woman presented with a palpable mass in the left breast. Imaging revealed synchronous bilateral breast tumors without evidence of nodal or distant metastasis. She underwent bilateral mastectomy and bilateral sentinel lymph node biopsy. The right breast tumor was a carcinoma with OGCs measuring 6 mm in diameter; it was estrogen receptor (ER)-positive, progesterone receptor (PgR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, had a Ki-67 labeling index of 10%, was nuclear grade 1/histological grade 1, and showed no lymphovascular invasion or nodal metastasis. The left breast tumor was an invasive ductal carcinoma (so-called scirrhous type), measuring 25 mm in diameter; it was ER-positive, PgR-positive, HER2-negative, had a Ki-67 labeling index of 10%, was nuclear grade 2/histological grade 2, showed lymphatic invasion, and had an Oncotype DX recurrence score of 16. Tamoxifen was initiated. CT performed 6 months after surgery as postoperative imaging follow-up for this patient revealed multiple pulmonary nodules, and PET-CT showed pulmonary and lumbar vertebral lesions. Pathological confirmation was not performed; therefore, the precise origin could not be determined. Fulvestrant plus abemaciclib was started for clinically suspected recurrent breast cancer.

CONCLUSIONS: This case illustrates that early distant recurrence can occur in synchronous bilateral hormone receptor-positive breast cancer even when available clinicopathological and genomic findings appear relatively favorable. However, because the left conventional invasive ductal carcinoma had more plausible recurrence-risk features than the small right-sided carcinoma with OGCs, and because the metastatic lesions were not pathologically confirmed, this case should not be interpreted as evidence that the OGC-containing carcinoma caused the recurrence. Rather, it highlights the diagnostic and risk-assessment complexity of synchronous bilateral breast cancer that includes a rare stromal-rich morphological pattern.

INTRODUCTION: Conservative management of perforated appendicitis is widely accepted; however, residual appendiceal tissue may persist and lead to delayed complications. We report a rare case of a retained viable appendiceal segment identified during interval appendectomy (IA).

CASE PRESENTATION: An 82-year-old patient was treated conservatively for perforated appendicitis without abscess formation but with marked periappendiceal inflammatory changes. Two months after the initial treatment, an IA was planned. Follow-up CT demonstrated enlargement of the appendix compared with the initial imaging. Intraoperatively, the appendix was found to be transected at the mid-portion. The distal segment was separated from the proximal stump and encapsulated by the omentum and small intestine with dense adhesions. This distal segment remained viable because it retained blood supply through the mesoappendix and showed inflammatory enlargement. Histopathological examination demonstrated preserved appendiceal wall structure with inflammatory cell infiltration, without evidence of necrosis or malignancy. The postoperative course was uneventful, and the patient was discharged on POD 3.

CONCLUSIONS: A retained viable appendiceal segment may persist and enlarge after perforated appendicitis treated conservatively, potentially leading to delayed complications such as secondary perforation or abscess formation; therefore, surgeons should be aware of this possibility and consider IA in selected patients. Careful attention should be paid to ensure complete removal of the appendix, including any detached distal segments.

INTRODUCTION: Disseminated carcinomatosis of the bone marrow (DCBM) is a rare but highly fatal complication in colorectal cancer (CRC) patients. Although previous reports have described favorable responses to urgent chemotherapy, we encountered 2 cases of CRC-associated DCBM with a devastating clinical course. Here, we present these cases and discuss current optimal management in light of the literature.

CASE PRESENTATION: The first patient was a 69-year-old man with stage IIIC rectal cancer who underwent high anterior resection with lymph node dissection and partial ileal and bladder resection after chemoradiotherapy. Four months after the surgery, the patient was admitted with severe fatigue. The second patient was a 69-year-old man with sigmoid colon cancer who underwent laparoscopic sigmoid colectomy with regional lymph node dissection. Pathological examination revealed lymph node metastases and peritoneal dissemination, and the disease was classified as stage IVC. He received 20 cycles of mFOLFOX6 plus bevacizumab; however, the peritoneal dissemination gradually progressed. Two years after the initial diagnosis, he was hospitalized due to fever of unknown origin. Both patients presented with cytopenia and circulating immature hematopoietic cells on admission and were promptly diagnosed with DCBM through hematology consultation, whole-body imaging, and bone marrow biopsy. Despite urgent initiation of systemic chemotherapy combined with a molecular-targeted agent and therapy for disseminated intravascular coagulopathy (DIC), hematologic abnormalities remained refractory, and both patients died shortly after diagnosis. Of note, the first patient delayed hospitalization due to financial reasons, resulting in severe DIC, rapid disease progression, and death eight days after admission.

CONCLUSIONS: This series emphasizes the extremely high mortality of CRC-associated DCBM and highlights the importance of earlier detection during routine follow-up and urgent intervention for oncological DIC, along with consideration of palliative care at the time of diagnosis. Further studies are needed to better understand its biology and optimal management.

INTRODUCTION: Endoscopic submucosal dissection (ESD) is a standard treatment for early gastric cancer; however, severe anatomical distortion caused by a large hiatal hernia can render the procedure technically infeasible. We report a case in which laparoscopic reduction enabled successful ESD in a 1-stage hybrid procedure.

CASE PRESENTATION: An older woman with a large type III hiatal hernia was diagnosed with early gastric cancer in the antrum, with most of the stomach herniated into the thoracic cavity. ESD was attempted but proved technically infeasible because of poor endoscopic maneuverability due to the intrathoracic displacement of the stomach. A 1-stage hybrid approach was therefore planned for treatment. With the patient under general anesthesia, laparoscopic reduction and posterior crural closure were performed to restore the normal hiatal anatomy. ESD was then performed under more stabilized conditions that allowed en bloc resection, while intraoperative endoscopy simultaneously enabled assessment of luminal narrowing at the esophagogastric junction. The anterior wall of the upper gastric body was fixed to the abdominal wall to prevent recurrence of the hernia. The patient’s postoperative course was uneventful. Histopathological examination of the resected specimen confirmed the curative resection of an intramucosal adenocarcinoma (pT1a, ly0, v0, HM0, VM0). No recurrence was observed during 3 years of follow-up.

CONCLUSIONS: A hybrid laparoscopic–endoscopic approach can enable ESD in otherwise technically infeasible cases by restoring anatomical configuration and stabilizing endoscopic maneuverability. This strategy may provide a safe and minimally invasive 1-stage treatment option.

INTRODUCTION: Goblet cell adenocarcinoma (GCA) is a rare malignancy of the appendix that often involves deeper layers of the bowel wall, making preoperative diagnosis difficult and occasionally mimicking inflammatory bowel disease.

CASE PRESENTATION: We report a 47-year-old man with a history of appendectomy who presented with an ileocecal stricture initially diagnosed as Crohn’s disease. As the stricture persisted despite repeated endoscopic balloon dilations, ileocecal resection was performed. Histopathological examination revealed that immunohistochemistry was positive for mucin 2, synaptophysin, and carcinoembryonic antigen, leading to a diagnosis of GCA. The patient received adjuvant chemotherapy with capecitabine and oxaliplatin and remains recurrence-free.

CONCLUSIONS: This case indicates that malignancy should be considered in treatment-refractory ileocecal strictures, even when endoscopic biopsy results are negative.

INTRODUCTION: Esophageal squamous cell carcinoma (ESCC) remains an extremely aggressive malignancy with a poor prognosis, particularly among patients with distant metastases. Although systemic chemotherapy is the standard of care for patients with stage IV disease, conversion surgery has emerged as a promising treatment strategy for selected patients who respond favorably to systemic therapy. The introduction of immune checkpoint inhibitors (ICIs) has increased the therapeutic opportunities. However, the optimal management of postoperative recurrence after ICI-based conversion surgery remains unclear. Here, we report a case of postoperative recurrent ESCC after ICI-based conversion surgery in which long-term disease control was achieved through sequential multidisciplinary treatment, including chemoradiotherapy and subsequent dual immune checkpoint blockade.

CASE PRESENTATION: A 68-year-old woman was diagnosed with stage IVB ESCC (cT3N2M1b) with para-aortic lymph node metastasis. The patient received 3 cycles of pembrolizumab combined with cisplatin and 5-fluorouracil (FP), which resulted in marked tumor regression. She underwent robot-assisted thoracoscopic subtotal esophagectomy with para-aortic lymphadenectomy; an R0 resection was achieved. The pathological diagnosis was squamous cell carcinoma with grade 2b tumor regression. Postoperative adjuvant therapy with nivolumab was initiated. Five months after surgery, locoregional recurrence occurred, and the patient was treated with chemoradiotherapy using docetaxel, followed by combination immunotherapy with nivolumab and ipilimumab. Remarkable regression of the recurrent lesions was achieved, and the patient has remained disease-controlled for 22 months postoperatively without further treatment.

CONCLUSIONS: Dual immune checkpoint blockade with nivolumab and ipilimumab may represent a potential therapeutic option for patients with recurrent ESCC following ICI treatment. This case underscores the importance of individualized treatment strategies and the evolving role of immunotherapy in the multidisciplinary management of patients with advanced esophageal cancer.

INTRODUCTION: Paraneoplastic vasculitis is an uncommon manifestation of malignancy and has been reported mainly in association with lung cancer, renal cell carcinoma, and hematologic malignancies. Breast cancer-associated vasculitis is rare, and presentation as large-vessel vasculitis (LVV) is particularly uncommon. We report a rare case of suspected paraneoplastic LVV occurring concurrently with breast cancer, in which inflammatory activity stabilized after surgical resection of the primary tumor.

CASE PRESENTATION: A 54-year-old woman presented with pain in the left upper limb and left thigh. CT suggested left breast cancer with ipsilateral axillary lymph node metastasis. PET/CT showed fluorodeoxyglucose uptake in the left breast lesion and left axillary lymph node, as well as in multiple large vessels, including the carotid arteries, subclavian arteries, aorta, iliac arteries, and femoral arteries. Laboratory testing revealed an elevated C-reactive protein level of 10.93 mg/dL, whereas immunoglobulin A and antineutrophil cytoplasmic antibodies were within the normal ranges. There was no evidence of infection, autoimmune disease, or drug-induced vasculitis. Because breast cancer-associated paraneoplastic LVV was suspected, prednisolone was initiated at 30 mg/day, resulting in rapid improvement in symptoms and inflammatory response. The patient subsequently underwent breast-conserving surgery with axillary lymph node dissection while receiving prednisolone at 15 mg/day. Pathological examination revealed invasive ductal carcinoma, pT1c pN1 cM0, stage IIA, luminal A subtype. After surgery, prednisolone was tapered to 5 mg/day without recurrence of vasculitis, and inflammatory activity remained controlled during follow-up.

CONCLUSIONS: LVV occurring concurrently with newly diagnosed breast cancer may represent a paraneoplastic manifestation after exclusion of autoimmune, infectious, and drug-induced causes. This case suggests that tumor resection may contribute to stabilization of inflammatory activity by reducing tumor-related antigenic or cytokine-mediated stimulation. Surgical treatment may therefore have a potential role not only in local oncological control but also in the management of paraneoplastic immune dysregulation in selected patients with resectable breast cancer.

INTRODUCTION: A solitary fibrous tumor (SFT) in the thorax typically originates from the visceral pleura, and its presentation as a mediastinal tumor is rare. We report a case of an SFT presenting as a mediastinal tumor with a history of coronary arterial bypass grafting (CABG), in which the left internal thoracic artery (LITA) graft was anastomosed to the left anterior descending artery (LAD), and the LITA graft provided blood flow to the tumor.

CASE PRESENTATION: A man in his 30s was referred to our department for the diagnosis and treatment of an anterior mediastinal mass. He had a history of CABG during childhood, in which the LITA graft was anastomosed to the LAD for a complication of the coronary artery of Kawasaki disease. The tumor was a well-defined anterior mediastinal mass measuring 8.7 cm in size, which was adjacent to the ascending aorta and chest wall but did not show invasiveness. A thymoma or low-grade mediastinal tumor was highly suspected on imaging. Evaluation of the coronary arteries and the graft demonstrated that the LITA graft provided a large amount of blood flow to the tumor, and the right coronary artery provided collateral flow to the LAD area. It is acceptable for the LITA graft to be sacrificed during surgery because of this collateral flow. Surgical resection via re-sternotomy and anterolateral left thoracotomy was performed. The tumor was successfully dissected from the surrounding tissue, and the pedicle of the tumor was recognized at the left upper lobe of the lung. Pathologically, the tumor was diagnosed as SFT without aggressive characteristics.

CONCLUSIONS: SFT presenting as a mediastinal tumor is rare, and impressive imaging of blood supply from the CABG graft was observed. Detailed coronary imaging contributed to the surgical strategy.

INTRODUCTION: Gastrointestinal arteriovenous malformations (AVMs) typically present with luminal gastrointestinal bleeding because they are generally located within the mucosa or submucosa. Intraperitoneal hemorrhage caused by a colonic AVM is exceedingly rare. Herein, we report a rare case of a colonic AVM that presented with intraperitoneal hemorrhage that required emergency surgical intervention.

CASE PRESENTATION: A 59-year-old man presented to a local hospital with left-sided abdominal pain. CT revealed intra-abdominal bleeding, and the patient was subsequently transferred to our institution. Although he was hemodynamically stable on arrival, repeat CT demonstrated an increase in the volume of intra-abdominal hemorrhage. Given the progression of intraperitoneal hemorrhage despite stable hemodynamic status and the absence of a definitive preoperative diagnosis, emergency surgery was performed. Upon laparotomy, approximately 600 mL of hemoperitoneum was identified. A 5-cm area of serosal disruption was observed in the descending colon, and partial colectomy with stapled anastomosis was undertaken. The postoperative course was uneventful, and the patient was discharged on POD 9. Gross examination of the resected specimen revealed an intact mucosal surface, whereas hemorrhage had extended to the serosal surface. Histopathological examination demonstrated irregularly dilated arteries and veins with arteriovenous shunts extending from the deep submucosa to the muscularis propria, confirming the diagnosis of AVM.

CONCLUSIONS: We report a rare case of intraperitoneal hemorrhage originating from a colonic AVM. In this case, bleeding from an AVM extending from the submucosa to the muscularis propria penetrated the serosal surface, resulting in intraperitoneal hemorrhage.

INTRODUCTION: Left ventricular assist devices (LVADs) are increasingly used as bridge-to-transplant or destination therapy for patients with advanced heart failure. As long-term survival improves, more recipients encounter noncardiac surgical conditions. Acute cholecystitis is one of the most common abdominal emergencies in this population and presents unique challenges due to continuous anticoagulation, altered hemodynamic physiology under continuous-flow support, and the presence of pump hardware and drivelines. Delay in treatment risks systemic infection or device contamination, potentially jeopardizing heart transplant eligibility. However, evidence guiding optimal surgical management in patients with prolonged LVAD support remains limited.

CASE PRESENTATION: A man in his 50s with a 6-year history of HeartMate II (Abbott Laboratories, Abbott Park, IL, USA) support presented with fever and right upper quadrant abdominal pain while waiting for deceased donor heart transplantation. Imaging confirmed acute cholecystitis with gallstones. Because of the physiological risks associated with pneumoperitoneum and the need for ongoing anticoagulation, percutaneous transhepatic gallbladder drainage (PTGBD) was performed first, leading to effective infection control. As prolonged catheter placement was undesirable in a transplant candidate, he subsequently underwent elective open cholecystectomy after multidisciplinary planning, perioperative anticoagulation adjustment with heparin bridging, and preoperative US mapping of the driveline. The operation was completed without device injury, uncontrollable bleeding, or hemodynamic instability. The postoperative course was uneventful, and the patient successfully underwent heart transplantation 4 months later.

CONCLUSIONS: This case demonstrates that a staged strategy consisting of early infection control followed by elective cholecystectomy can be safely applied in LVAD-supported patients awaiting heart transplantation. Individualized perioperative planning, optimized anticoagulation management, and precise assessment of driveline anatomy are essential to ensure surgical safety and to preserve transplant eligibility in this high-risk population.

INTRODUCTION: Metastatic tumors to the pancreas account for approximately 2% of all pancreatic malignancies, and pancreatic metastasis from distal cholangiocarcinoma is extremely rare. Differentiating pancreatic metastasis of cholangiocarcinoma from primary pancreatic cancer is often difficult, as both typically present as adenocarcinoma with similar immunohistochemical features.

CASE PRESENTATION: A 65-year-old man underwent subtotal stomach-preserving pancreatoduodenectomy (SSPPD) for distal cholangiocarcinoma. He was diagnosed with pT3N0M0, Stage IIB according to the UICC TNM classification, 8th edition. Seven years after surgery, a routine blood test revealed an elevated serum carbohydrate antigen 19-9 level. Abdominal MRI and CT demonstrated 2 small masses, each approximately 10 mm in diameter, in the remnant pancreas without evidence of distant metastasis. Both lesions were diagnosed as adenocarcinoma by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), suggesting either pancreatic metastases from distal cholangiocarcinoma or primary pancreatic cancer in the remnant pancreas. Completion total pancreatectomy with splenectomy was therefore performed. Histopathological examination showed that both lesions in the remnant pancreatic tail were morphologically similar to the initial cholangiocarcinoma. However, the possibility of primary pancreatic cancer could not be completely excluded. Comprehensive genomic profiling (CGP) of the initial cholangiocarcinoma and the remnant pancreatic tumor revealed a shared TP53 H214R alteration, supporting the diagnosis of pancreatic metastases from distal cholangiocarcinoma. In addition, CGP identified BRCA1 loss and an FGFR3 alteration in the remnant pancreatic tumor as potentially actionable findings, although their therapeutic relevance in cholangiocarcinoma remains uncertain.

CONCLUSIONS: We report a rare case of multiple pancreatic metastases occurring 7 years after resection of distal cholangiocarcinoma. Evaluation of genetic alterations provided supportive evidence to aid in distinguishing metastatic disease from primary pancreatic cancer in the remnant pancreas. In addition, these findings also suggested potentially relevant therapeutic targets.

INTRODUCTION: The classic differential diagnosis of a progressive gastric submucosal tumor (SMT) includes gastrointestinal stromal tumor (GIST), lymphoma, and leiomyoma. But idiopathic pseudoaneurysm is seldom seen. We report the first case of a gastric idiopathic pseudoaneurysm that could not be diagnosed preoperatively.

CASE PRESENTATION: An 83-years-old female was referred to our department (Center of Gastroenterology and Oncology, IMS Ota Chuo General Hospital) due to a 39 mm gastric mass accidentally found by CT scan. This mass had rapidly increased in size from 26 to 39 mm in 4 months. She had been seeing cardiology for atrial fibrillation on direct oral anticoagulant drug (DOAC) and chronic heart failure. Diffusion weight image (DWI) of MRI showed a high-intensity area in this mass. We diagnosed rapid progressive SMT and performed distal gastrectomy. The pathological finding was a pseudoaneurysm in the subserosal layer. Since she had no history of trauma or vasculitis, we diagnosed it as an idiopathic pseudoaneurysm. DOAC might contribute to the formation of this pseudoaneurysm. She had no recurrence in 3 years of follow up. To the best of our knowledge, this is the first reported case.

CONCLUSIONS: Gastroenterologists should consider pseudoaneurysm in the differential diagnosis of rapid progressive SMT.

INTRODUCTION: Glomus tumors are rare perivascular neoplasms that typically occur in the distal extremities. Their occurrence in the chest wall is extremely rare, with only 13 cases previously reported in the English literature. Herein, we report a unique case of a primary chest wall glomus tumor in a patient who presented with severe, rapidly worsening back pain, underwent ¹⁸F-fluorodeoxyglucose-PET/CT (FDG-PET/CT) evaluation, and experienced complete pain resolution following thoracoscopic resection.

CASE PRESENTATION: A 65-year-old man presented to our emergency department with a 1-month history of progressively worsening right posterior back pain. Contrast-enhanced CT revealed a 20 × 13-mm well-enhanced oval mass in the right posterior chest wall at the level of the ninth rib. MRI demonstrated heterogeneous intensity on T2-weighted images. FDG-PET/CT showed low tumor uptake with a maximum standardized uptake value (SUVmax) of 2.2. This finding was considered adjunctive metabolic information that did not strongly suggest a highly aggressive malignancy; however, it was insufficient to exclude malignancy or establish a definitive diagnosis. To achieve a definitive diagnosis and alleviate the severe pain, surgical resection was performed via 4-port video-assisted thoracoscopic surgery (VATS). The tumor was completely excised with clear margins. Histopathological and immunohistochemical analyses confirmed the diagnosis of a benign glomus tumor, with diffuse positivity for smooth muscle actin (SMA) and a Ki-67 labeling index of less than 1%. The patient’s severe back pain completely resolved immediately after surgery, and he remained completely asymptomatic with no evidence of recurrence at the 10-year follow-up.

CONCLUSIONS: Although exceedingly rare, glomus tumors should be included in the differential diagnosis of painful chest wall tumors. FDG-PET/CT may provide adjunctive information regarding metabolic activity during preoperative assessment; however, its findings should be interpreted cautiously and cannot replace histopathological evaluation. To the best of our knowledge, this is the first reported case of a chest wall glomus tumor evaluated with FDG-PET/CT. Complete surgical resection remains essential for definitive diagnosis and symptom relief, and minimally invasive resection via VATS may be an effective approach when complete resection is feasible.

INTRODUCTION: Adenocarcinomas originating at stoma sites are extremely rare. While many cases are associated with colorectal cancer or inflammatory bowel disease, instances without such predisposing factors are even rarer.

CASE PRESENTATION: A 39-year-old man with a history of Hirschsprung’s disease presented with tumor growth at his permanent stoma site, which had been established 27 years earlier. A biopsy confirmed adenocarcinoma. Preoperative imaging, including CT, MRI, and PET-CT, showed no evidence of lymph node or distant metastasis. Immunohistochemical staining (CK7+, CK20+, CDX2+) was consistent with a primary tumor of the small bowel. Based on the preoperative diagnosis of localized disease and the clinical goal of preserving intestinal function, local resection was performed with negative margins. Histopathological examination confirmed a primary ileal adenocarcinoma. The patient remains recurrence-free 30 months postoperatively without adjuvant chemotherapy.

CONCLUSIONS: This report presents a rare case of stoma-site adenocarcinoma arising 27 years after surgery for Hirschsprung’s disease. In long-term survivors of pediatric stoma surgery, chronic physical and chemical irritation may contribute to malignancy even in the absence of a predisposing malignant background. Malignancy at the stoma site can be discovered by patients through self-examination; therefore, both patients and clinicians must recognize the potential risk for early detection.

INTRODUCTION: Acute appendicitis is the most common non-obstetric surgical emergency during pregnancy, occurring in approximately 1 in 1000–2000 pregnancies. Although laparoscopic appendectomy (LA) offers advantages over open appendectomy, including reduced postoperative pain and a shorter hospital stay, its application in pregnant patients remains debated due to concerns about fetal effects and the technical challenges posed by the enlarged uterus.

CASE PRESENTATION: We retrospectively reviewed 6 consecutive pregnant women who underwent LA for acute appendicitis at our institution between April 2020 and April 2025, focusing on intraoperative techniques and surgical outcomes. Patient age ranged from 28 to 37 years (median, 31.5 years) and gestational age from 15 to 33 weeks (median, 21.0 weeks). All cases were completed laparoscopically using a 3-port technique, with intraperitoneal insufflation pressure maintained at 10–12 mmHg. A supine position was used in 4 cases (≤20 weeks of gestation) and a left lateral decubitus position in 2 cases (≥21 weeks). The median operative time was 84 min (range, 64–124 min), blood loss was 0 g in 5 cases (5 g in 1), and the median postoperative hospital stay was 5 days (range, 2–7 days). Pathological findings included 1 catarrhal, 4 phlegmonous, and 1 gangrenous appendicitis. No conversions to open surgery occurred, and no obstetric complications were observed in any case.

CONCLUSIONS: By tailoring patient positioning and port placement to gestational age, LA was safely performed during the 2nd and 3rd trimesters. LA appears to be a safe and effective treatment for acute appendicitis during pregnancy when appropriate intraoperative precautions are applied.

INTRODUCTION: Rhabdomyosarcoma (RMS) is the most common malignant soft tissue tumor in children, with the alveolar subtype associated with an aggressive clinical course and poor prognosis. Metastasis to the breast from RMS is extremely rare, particularly in preadolescent patients, and optimal local treatment strategies have not been established.

CASE PRESENTATION: We report the case of a 9-year-old girl with alveolar RMS originating in the left lower extremity. The patient underwent wide resection of the primary tumor and dissection of the regional lymph node, followed by multimodal therapy, including chemotherapy and proton beam radiotherapy, and achieved complete remission. Three months after the completion of treatment, she developed a palpable mass in the right breast. Imaging studies revealed multiple breast lesions without evidence of local recurrence at the primary site. Histopathological examination confirmed the presence of metastatic RMS. Preoperative chemotherapy resulted in a limited tumor response, and local control was pursued. An endoscopic-assisted nipple–areola-sparing mastectomy with partial resection of the pectoralis major muscle was performed, followed by adjuvant chemotherapy and radiotherapy. Immunohistochemical findings supported the diagnosis of metastatic RMS. Comprehensive genomic profiling of the metastatic lesion identified a TP53 pathogenic variant. However, germline testing was not performed, and the clinical significance of this finding remains uncertain. Despite aggressive multidisciplinary treatment, the patient developed widespread metastatic disease and died approximately 4 years after the initial diagnosis.

CONCLUSIONS: Breast metastasis from alveolar RMS is rare but should be considered in pediatric patients who present with breast masses after treatment. Surgical resection may contribute to local control and QOL in selected cases. Additional cases are needed to clarify the role of surgery and to establish optimal treatment strategies, particularly in patients with suspected hereditary cancer predisposition syndromes.

INTRODUCTION: Japanese spotted fever (JSF) is a tick-borne infection caused by Rickettsia japonica, classically presenting with the triad of fever, rash, and eschar, and characterized by systemic vasculitis resulting from endothelial injury. Concomitant cholecystitis associated with JSF is exceedingly rare.

CASE PRESENTATION: We report the case of a 77-year-old man who presented with fever, was diagnosed with calculous cholecystitis at a referring hospital, and underwent laparoscopic cholecystectomy. Postoperatively, erythema developed on the extremities and trunk, along with an eschar on the right ankle. Polymerase chain reaction (PCR) testing subsequently detected R. japonica, confirming JSF. The ischemic injury secondary to vasculitis may have contributed to the development of cholecystitis.

CONCLUSIONS: Even in calculous cholecystitis, JSF should be considered in endemic areas when rash or eschar is present, highlighting the importance of early PCR testing and the prompt administration of tetracyclines.

INTRODUCTION: Robotic-assisted aortic valve replacement (AVR) has emerged as an extension of minimally invasive cardiac surgery, offering enhanced visualization and articulated instrument control. However, patients with severe thoracic deformities and markedly narrow chest anatomy are generally considered challenging candidates because restricted operative space may compromise annular exposure, instrument maneuverability, and aortotomy closure. Reports describing robotic-assisted AVR in such patients remain limited. We describe a successful robotic-assisted AVR in a patient with severe scoliosis and a markedly narrow thoracic cavity, highlighting technical modifications that enabled safe valve implantation.

CASE PRESENTATION: A 61-year-old man presented with progressive exertional dyspnea and fatigue caused by severe aortic regurgitation. CT demonstrated severe scoliosis with marked narrowing of the thoracic cavity, resulting in a sternovertebral distance of 6.5 cm. The patient also had a stable chronic type B aortic dissection extending from the descending thoracic aorta to the level of the superior mesenteric artery without involvement of the ascending aorta or aortic arch. After multidisciplinary discussion and informed consent, robotic-assisted AVR was performed using the da Vinci Xi system (Intuitive Surgical, Sunnyvale, CA, USA). Technical modifications included the placement of the service-port robotic arm in the fifth intercostal space to improve the working angle and avoid arm interference, and the creation of a longitudinal aortotomy to facilitate valve exposure in the restricted operative field. Exposure of the noncoronary and left coronary annulus was achieved through robotic retraction and bedside suction assistance. A 23-mm bioprosthetic valve was successfully implanted without intraoperative complications. The patient was extubated within 5 h and discharged on POD 20. Postoperative echocardiography demonstrated normal prosthetic valve function without paravalvular leakage.

CONCLUSIONS: Robotic-assisted AVR may be feasible in carefully selected patients with scoliosis-associated narrow chest anatomy. Detailed preoperative assessment and tailored technical strategies, including longitudinal aortotomy and modified port placement, may facilitate adequate exposure and safe valve implantation in anatomically challenging cases.

INTRODUCTION: Pancreatoduodenectomy in patients with celiac axis (CA) stenosis or occlusion carries a risk of ischemic complications because hepatic arterial flow may depend on collateral circulation from the superior mesenteric artery. Although securing hepatic arterial flow is essential, preservation of gastric perfusion has rarely been emphasized. Herein, we report a case of pancreatic head cancer with severe atherosclerotic CA stenosis and common hepatic artery (CHA) occlusion, in which arterial reconstruction (ARc) and preserving the right gastric vessels were combined to maintain both hepatic and gastric perfusion.

CASE PRESENTATION: A 76-year-old man was referred to our hospital after an incidental pancreatic head mass was detected using CT. Dynamic contrast-enhanced CT revealed a 15-mm hypovascular tumor in the pancreatic head with dilation of the main pancreatic duct and no major vascular invasion or distant metastasis. Preoperative imaging revealed severe atherosclerotic CA stenosis and CHA occlusion, with marked development of the pancreatoduodenal arcade, suggesting dependence on collateral flow. The right gastric artery (RGA) was relatively large. A pylorus-preserving pancreatoduodenectomy (PPPD) was performed. The ARc was established between the right common iliac artery (RCIA) and the gastroduodenal artery (GDA) stump using a great saphenous vein graft. The RGA and vein were preserved to maintain gastric perfusion. Intraoperative Doppler ultrasonography and indocyanine green fluorescence imaging confirmed adequate hepatic and gastric perfusion, respectively. The operation time was 582 min, with blood loss of 252 mL. Histopathological examination revealed a moderately differentiated adenocarcinoma with lymph node metastasis (pT1N1M0, Stage IIB). All resection margins were pathologically negative, and an R0 resection was achieved. The postoperative course was uneventful, and postoperative CT demonstrated adequate organ perfusion and bypass graft patency. The patient remained recurrence-free for 5 months after surgery.

CONCLUSIONS: PPPD with an ARc between the RCIA and GDA stump, combined with right gastric vessel preservation, enabled safe resection in a patient with severe CA stenosis and CHA occlusion. Preoperative hemodynamic assessment may help guide individualized revascularization and vessel preservation. However, because direct intraoperative assessment of gastric perfusion under RGA clamping was not performed, the necessity of RGA preservation could not be objectively confirmed in this case.

INTRODUCTION: Ectopic pancreas is defined as pancreatic tissue lacking anatomical and vascular continuity with the main pancreas. Malignant transformation within ectopic pancreatic tissue is extremely rare, and cases arising in the mesentery are exceptionally uncommon. We report a rare case of adenocarcinoma arising from ectopic pancreatic tissue in the proximal jejunal mesentery.

CASE PRESENTATION: An 80-year-old man presented with abdominal pain. Contrast-enhanced CT showed a 3-cm mass adjacent to the proximal jejunum, initially suspected to be a jejunal submucosal tumor, such as gastrointestinal stromal tumor. Laparoscopy identified a firm mesenteric tumor closely associated with the superior mesenteric artery and jejunal branches, necessitating conversion to open surgery. The tumor was completely excised while preserving the small intestine. Histopathological examination demonstrated well-differentiated adenocarcinoma arising within ectopic pancreatic tissue containing acinar, ductal, and islet of Langerhans. Immunohistochemistry showed positive staining for carbohydrate antigen 19-9, p16, p53, and S100A4, supporting the diagnosis of pancreatic ductal adenocarcinoma. The postoperative course was uneventful except for transient paralytic ileus. The patient was discharged on POD 19 and has remained recurrence-free for 9 months.

CONCLUSIONS: Adenocarcinoma arising from ectopic pancreatic tissue in the mesentery is exceedingly rare and difficult to diagnose preoperatively. Complete surgical excision is essential for definitive diagnosis and curative treatment. Further case accumulation is required to better define its clinical characteristics and optimal treatment strategies.

INTRODUCTION: Simultaneous pancreas–kidney transplantation (SPK) is an established treatment for patients with type 1 diabetes mellitus complicated by end-stage renal disease. In retransplantation cases, removal of the existing graft may be required, and severe adhesions around the graft increase the risk of vascular injury. In particular, bleeding from deep vessels can be difficult to control because vascular exposure and clamping are often challenging.

CASE PRESENTATION: A 45-year-old woman with end-stage renal disease secondary to type 1 diabetes mellitus had previously undergone living-donor kidney transplantation. The graft function deteriorated due to treatment-resistant rejection, and she was scheduled for SPK after receiving a deceased donor organ. During removal of the existing renal graft in the left iliac fossa, the external iliac artery was injured, resulting in uncontrolled arterial bleeding that could not be managed by compression, suturing, or vascular clamping. A resuscitative endovascular balloon occlusion of the aorta (REBOA) catheter was inserted via the left femoral artery and used for temporary blood flow control of bleeding from the injured external iliac artery. This stabilized both the hemodynamics and the operative field, allowing successful suture repair of the arterial injury. Subsequently, kidney and pancreas transplantation were completed. The postoperative course was uneventful.

CONCLUSIONS: In SPK with retransplantation, vascular injury may occur during graft removal. Temporary blood flow control using REBOA may be a useful strategy for achieving hemostasis and securing the operative field in cases of localized arterial injury.

INTRODUCTION: Intra-abdominal desmoid tumors (DTs) are rare non-metastatic fibroblastic neoplasms that commonly develop at sites of prior surgical trauma or inflammation. Here, we report a diagnostically challenging case of a DT mimicking tumor recurrence or primary malignancy following laparoscopic distal pancreatectomy.

CASE PRESENTATION: A 69-year-old woman with a history of laparoscopic ileocecal resection for Stage I cecal cancer underwent laparoscopic distal pancreatectomy with splenectomy for suspected pancreatic cancer. Histopathology of the resected pancreas revealed low-grade pancreatic intraepithelial neoplasia (PanIN-1/2), which was considered responsible for the main pancreatic duct obstruction, with a minute neuroendocrine tumor (NET) (Grade 1, 1.9 mm) identified in the vicinity. The patient developed a Grade B postoperative pancreatic fistula (POPF) requiring prolonged drainage. Ten months later, follow-up CT revealed an 18-mm nodule in the transverse mesocolon. ¹⁸F-fluorodeoxyglucose PET/CT (FDG-PET/CT) demonstrated intense focal FDG accumulation (maximum standardized uptake value = 4.6), whereas somatostatin receptor scintigraphy was negative. The tumor grew rapidly to 31 mm over 4 months. Differential diagnoses included recurrence of the primary NET, peritoneal dissemination from occult pancreatic adenocarcinoma (given the PanIN background), or a primary mesenteric gastrointestinal stromal tumor. Due to a high suspicion of malignancy, laparoscopic diagnostic resection was performed. Intraoperatively, the tumor was found to have infiltrated the mesentery of the transverse colon and jejunum, requiring delicate dissection to preserve the middle colic artery and first jejunal vessels. Histopathological examination revealed a spindle cell neoplasm with nuclear accumulation of β-catenin, ruling out malignant recurrence and confirming a DT. Chronic chemical irritation resulting from the preceding POPF is considered a likely trigger.

CONCLUSIONS: Intra-abdominal DTs can mimic malignant recurrence on FDG-PET/CT after pancreatic surgery. This case highlights that clinicians should include DTs in the differential diagnosis of mesenteric masses arising at the site of prior postoperative complications, such as a pancreatic fistula.

INTRODUCTION: Cases of hiatal hernia (HH) involving the distal stomach, duodenum, and ascending and transverse colon are exceptionally rare and present significant surgical challenges owing to severe anatomical distortion. Although minimally invasive surgery is the gold standard for HH repair, the application of a robotic approach to this specific complex configuration involving distal gastric and duodenal herniations has not been previously reported. Here, we present the case of such a defect that was managed successfully using a robotic platform.

CASE PRESENTATION: A 36-year-old female presented with worsening vomiting and an inability to tolerate oral intake for 1 week prior to admission. Her history included 2 recent pregnancies and deliveries within the last 2 years, which likely precipitated the symptoms due to increased intra-abdominal pressure. CT of the abdomen and pelvis revealed a massive HH. The herniated contents included the lower gastric body, antrum, duodenal bulb, and ascending and transverse colon, all of which were displaced into the right hemithorax via a defect in the right crus of the diaphragm. The patient underwent a total robotic repair using the da Vinci Xi surgical system (Intuitive Surgical, Sunnyvale, CA, USA). The procedure involved careful reduction of the herniated viscera and meticulous mediastinal dissection of the hernial sac using a soft coagulation technique. The robotic platform facilitated the identification and preservation of the anterior and posterior vagal trunks. The crural defect was repaired using nonabsorbable sutures (Ethibond 2-0; Ethicon, Raritan, NJ, USA). Owing to the emergency setting and extensive anatomical distortion, anterior gastropexy was performed instead of fundoplication to secure the stomach and prevent recurrence. Obstructive symptoms resolved immediately postoperatively. She successfully transitioned to oral intake. The chest tube was removed on POD 5, and she was discharged on day 7 without complications.

CONCLUSIONS: This case demonstrates the feasibility and safety of a completely robotic approach for repairing complex HH involving the distal stomach, duodenum, and ascending and transverse colon. The robotic platform’s superior 3D visualization and wrist articulation are distinct advantages for performing precise dissection in the confined mediastinal space, ensuring safe reduction and preservation of critical structures such as the vagal nerves.

INTRODUCTION: Interparietal hernia (IPH) is a rare subtype of inguinal hernia in which the hernial sac extends between the layers of the abdominal wall musculature. Due to its unusual anatomical location, preoperative diagnosis is often difficult. Reports of adult cases in the English-language literature remain extremely limited. IPH occurring in association with a recurrent inguinal hernia is even rarer.

CASE PRESENTATION: A man in his 70s with a history of bilateral inguinal hernia repair presented with abdominal pain and constipation. Contrast-enhanced CT revealed herniation of the sigmoid colon from the internal inguinal ring, with the hernial sac extending cranially between the external and internal oblique muscles. Based on these findings, an interstitial IPH associated with a recurrent inguinal hernia was suspected. Manual reduction was successfully performed, and elective surgery was planned. Subsequently, laparoscopic transabdominal preperitoneal repair (TAPP) was performed. Intraoperative findings confirmed a recurrent inguinal hernia with cranial extension of the hernia sac between the abdominal wall muscle layers. After adequate dissection of the preperitoneal space, a 17 × 12-cm self-gripping mesh (ProGrip) was placed to cover the entire myopectineal orifice. The postoperative course was uneventful, and the patient was discharged on POD 2. No recurrence was observed during the 6-month follow-up period.

CONCLUSIONS: IPH associated with recurrent inguinal hernia is extremely rare. Careful interpretation of preoperative CT findings may facilitate the accurate recognition of this unusual hernia subtype and assist surgeons in selecting an appropriate surgical strategy. Awareness of this rare condition may improve preoperative assessment and operative planning in patients with atypical inguinal hernias.

INTRODUCTION: Phyllodes tumors of the breast are rare fibroepithelial neoplasms accounting for 0.3%–1.0% of all primary breast tumors. They are classified into benign, borderline, and malignant subtypes, with borderline and malignant tumors associated with an increased risk of local recurrence and distant metastasis. Giant phyllodes tumors, defined as tumors larger than 10 cm in diameter, are uncommon, and reports of tumors exceeding 20 cm are extremely rare. We report a case of a rapidly growing giant benign phyllodes tumor with skin ulceration, along with a review of the relevant literature.

CASE PRESENTATION: A 48-year-old Asian woman presented with rapid enlargement of the left breast and active bleeding from an ulcerated mass. Clinical findings and imaging studies revealed a well-circumscribed giant tumor measuring 24 cm that occupied the entire left breast, without evidence of distant metastasis. Core needle biopsy suggested a fibroepithelial tumor, and a benign phyllodes tumor was most strongly considered. A left mastectomy was performed. Skin grafting had been considered preoperatively, as the skin defect would be large. However, as sufficient skin flaps were obtained intraoperatively, due to the skin being stretched by the tumor, only mastectomy was done without a reconstructive procedure. Histopathological examination confirmed a benign phyllodes tumor with negative surgical margins. The postoperative course was uneventful.

CONCLUSIONS: We experienced a rare case of a giant breast tumor and tumor resection. Although rapid breast tumor growth and skin breakdown suggested malignancy, the pathological diagnosis was a benign phyllodes tumor. This highlights the importance of considering phyllodes tumors in the differential diagnosis of rapidly enlarging breast masses and the need for timely surgical intervention. This case is particularly noteworthy because it demonstrates an unusual combination of clinical features—giant tumor size, rapid growth, and skin ulceration—that are generally associated with malignant disease, despite the final diagnosis being benign.

INTRODUCTION: Cefmetazole (CMZ) is frequently used in abdominal surgery and critical care settings. Although cephalosporins containing an N-methyl-tetrazole-thiol (NMTT) side chain interfere with vitamin K metabolism, life-threatening clinically significant bleeding associated with CMZ-induced coagulopathy has rarely been reported.

CASE PRESENTATION: A 78-year-old woman with severe infections developed severe vitamin K–dependent coagulopathy during CMZ therapy. She subsequently experienced worsening upper gastrointestinal bleeding complicated by hemorrhagic shock in the setting of severe vitamin K–dependent coagulopathy despite preserved platelet counts and fibrinogen levels. Coagulation abnormalities rapidly improved following vitamin K administration, and no recurrence was observed after CMZ discontinuation.

CONCLUSIONS: This case report highlights CMZ-induced vitamin K–dependent coagulopathy as a rare but life-threatening adverse event in critically ill older patients. Coagulation parameters should be carefully monitored during CMZ therapy, particularly in high-risk patients.

INTRODUCTION: Congenital peritoneal encapsulation (CPE) is a rare anomaly in which the small intestine is enclosed in a thin peritoneal sac. Although mostly asymptomatic, CPE can cause severe intestinal obstruction due to strangulation and torsion.

CASE PRESENTATION: A 16-year-old male patient had been experiencing recurrent intestinal obstruction of unknown cause since the age of 13. He was admitted with persistent abdominal pain as his chief complaint, and emergency laparoscopic surgery was performed due to a suspected strangulating intestinal obstruction. The findings included an abnormal course of the inferior mesenteric vein (IMV), severe intussusception of the small intestine into the descending mesentery, ileal adhesions, and a segment of the small intestine covered by a thin membrane. The patient was diagnosed with CPE and a left paraduodenal hernia. Initially, the hernia was treated with manual reduction, and CPE was managed by excising the accessory peritoneal membrane and performing adhesiolysis. However, recurrent obstruction occurred due to dense terminal ileal readhesion, necessitating a reoperation on the 21st POD. During reoperation, side-to-side strictureplasty was performed for the adhesion, and the paraduodenal hernia was definitively managed by unroofing the hernia sac. The patient recovered uneventfully, without recurrence.

CONCLUSIONS: Complex congenital anatomical abnormalities, such as CPE and internal hernias, should be considered in recurrent intestinal obstruction from childhood to young adulthood. If CPE is confirmed intraoperatively, investigation of other congenital anomalies is warranted, and the possibility of robust postoperative adhesions due to congenital fusion planes must be considered.

INTRODUCTION: Colorectal mixed neuroendocrine–non-neuroendocrine neoplasms (MiNENs) are rare and aggressive tumors characterized by marked intratumoral heterogeneity, often making preoperative diagnosis difficult. Consequently, definitive diagnosis is frequently established only after surgical resection, and postoperative pathological findings may influence subsequent treatment strategies.

CASE PRESENTATION: A 66-year-old man presented with bloody stool. Colonoscopy revealed a cecal tumor, and biopsy demonstrated moderately differentiated adenocarcinoma. Laparoscopic ileocecal resection with D3 lymph node dissection was performed. Histopathological examination of the resected specimen revealed a collision-type MiNEN composed of neuroendocrine carcinoma (NEC) (60%) and adenocarcinoma (40%). The NEC component showed lymphovascular invasion, deep mesenteric invasion, and a Ki-67 index of approximately 50%–60%. Although regional lymph node metastasis involved only the adenocarcinoma component, comprehensive pathological assessment suggested biologically aggressive behavior of the NEC component, raising concern for potential systemic dissemination. Accordingly, NEC-oriented adjuvant chemotherapy with carboplatin plus etoposide was administered after curative resection. The patient remained recurrence-free until death from other causes 2 years after surgery.

CONCLUSIONS: Colorectal MiNEN poses substantial diagnostic challenges because biopsy specimens may not adequately represent both tumor components. Comprehensive pathological assessment of the resected specimen is important for identifying the aggressive component most likely to influence prognosis and for optimizing postoperative therapeutic strategy.

INTRODUCTION: Exuberant type 2 pneumocyte hyperplasia is a rare histopathological pattern of reactive epithelial change associated with spontaneous pneumothorax, in which preoperative clinical findings and radiological images usually show only nonspecific bullae and blebs. However, it is difficult to differentiate this entity from other conditions, especially pulmonary epithelial tumors, creating significant diagnostic pitfalls in postoperative histopathological evaluation.

CASE PRESENTATION: A 28-year-old man presented with recurrent left-sided spontaneous pneumothorax. Preoperative chest CT revealed subpleural blebs at the left lung apex and in the left lower lobe, without pulmonary nodules or mass lesions. Video-assisted thoracoscopic bullectomy was performed to remove 2 lesions. On gross pathological examination, bullae were observed just below the pleura, consistent with the cause of pneumothorax. In addition, histological examination revealed multiple nodular lesions several millimeters in size within the pulmonary parenchyma, and the airspaces were collapsed due to proliferation of bronchioloalveolar epithelium and accumulation of alveolar macrophages. Despite apparent cytological atypia and high proliferative activity demonstrated by immunohistochemistry (Molecular Immunology Borstel-1 index: 60%), the distinctive histopathological features supported the diagnosis of exuberant type 2 pneumocyte hyperplasia rather than primary or metastatic neoplasia. The patient has been well for over a year after surgery without recurrence.

CONCLUSIONS: Spontaneous pneumothorax is a common condition, but it can also occur secondary to tumors. It is important to differentiate exuberant type 2 pneumocyte hyperplasia from lung tumors, especially atypical adenomatous hyperplasia and adenocarcinoma. Careful histological examination of resected surgical specimens is essential even in cases suspected of primary spontaneous pneumothorax without radiologically apparent tumor-like lesions, to avoid misdiagnosis and overtreatment.

INTRODUCTION: Gastric neuroendocrine tumors (gNETs) are rare neoplasms; their coexistence with a congenital portosystemic shunt (CPSS) presents unique surgical challenges caused by the risks of intraoperative hemorrhage and postoperative hepatic dysfunction secondary to altered portal hemodynamics. To the best of our knowledge, no reports have described robot-assisted gastrectomy preserving a CPSS during gNET resection.

CASE PRESENTATION: A 54-year-old man presented with gastrointestinal hemorrhage and was diagnosed with a gNET (G1). Contrast-enhanced CT revealed a CPSS connecting the left gastric vein (LGV) and left renal vein (LRV) adjacent to the stomach. Given the absence of hepatic dysfunction and the potential risk of portal hypertension after shunt interruption, preservation of the anomalous vessel was planned. Robot-assisted distal gastrectomy with D2 lymphadenectomy was performed. The robotic platform provided stable 3D visualization and facilitated precise dissection around the anomalous vessel, thereby enabling complete tumor resection with adequate margins while preserving the shunt. Histopathological examination confirmed a G1 neuroendocrine tumor, without lymph node metastasis. The postoperative course was uneventful, with no hepatic or oncological complications.

CONCLUSIONS: Robot-assisted gastrectomy may facilitate safe and precise resection in selected patients with gNETs concurrent with CPSSs.

INTRODUCTION: The right S7 segment is the smallest pulmonary segment. Securing an adequate surgical margin during S7 segmentectomy can be challenging, particularly when the tumor is located more centrally. Radiofrequency identification (RFID) marking systems provide substantial benefits in detecting small nodules as well as ensuring an adequate resection margin from the marking site.

CASE PRESENTATION: A 67-year-old man with a history of renal cell carcinoma was referred to Kyushu University Hospital with a 9-mm solid nodule located deep within the right S7 segment. Given its central and deep location, preoperative RFID marker placement was performed in a hybrid operating room under cone-beam CT guidance. Subsequently, thoracoscopic S7 segmentectomy was performed using a confronting upside-down video-assisted thoracoscopic surgery approach. The RFID probe enabled precise intraoperative localization of the tumor and continuous confirmation of its surgical margin from the intersegmental plane. Pathological examination revealed papillary adenocarcinoma and confirmed complete resection. The patient’s postoperative course was uneventful.

CONCLUSIONS: RFID represents a valuable adjunct for segmentectomy of deeply or centrally located pulmonary nodules.

INTRODUCTION: Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare extranodal lymphoma, accounting for <1% of non-Hodgkin lymphomas, which most commonly affects Asians. MEITL mainly occurs in the small intestine and is characterized by an aggressive clinical course with a poor prognosis. MEITL shows intractable symptoms and frequently causes perforation and bleeding of the gastrointestinal tract. Bowel perforation and/or bleeding often require emergency surgery.

CASE PRESENTATION: A 77-year-old woman developed left-sided pain nearly at the umbilicus. CT revealed jejunal wall thickening measuring 60 mm. The lesion was hypervascular and showed gradual enhancement. The irregularly shaped tumor invaded the abdominal wall and transverse colon. Endoscopic findings showed a large ulcerative mass accompanied by severe necrosis. Radiographic findings of a small bowel series revealed a long, narrowed segment. Partial resection of the jejunum and planned dissection of the regional lymph nodes were performed, and partial resections of the abdominal wall and transverse colon were performed simultaneously. Histopathologically, diffuse and monotonous proliferation of medium-sized atypical lymphocytes was observed, and invasion into the abdominal wall and transverse colon was confirmed. A definitive diagnosis of MEITL was made based on histopathological assessment and immunohistochemistry. PET/CT revealed multiple areas of increased uptake in the small intestine. Serum levels of soluble interleukin-2 receptor were progressively elevated over time. The patient refused further aggressive treatment for MEITL. She died because of disease progression 142 days after symptom onset.

CONCLUSIONS: Clinicians should be aware that Asian patients who have small intestinal lesions accompanied by refractory symptoms, including bowel perforation and/or bleeding, may have MEITL. Surgeons should work closely with clinicians, and emergency surgery should be considered for suspected bowel perforation and/or bleeding in MEITL patients.

INTRODUCTION: Femoral venous cannulation is widely used to establish cardiopulmonary bypass (CPB) during minimally invasive cardiac surgery (MICS). Although transesophageal echocardiography (TEE) is commonly used to guide cannula placement, cannula malposition can still occur, and preserved venous drainage may delay the recognition of cardiac injury. We report a rare case of right ventricular perforation caused by femoral venous cannulation during minimally invasive aortic valve replacement (AVR), emphasizing that adequate venous drainage does not exclude cannula malposition or cardiac perforation.

CASE PRESENTATION: A 79-year-old man with severe aortic stenosis underwent minimally invasive AVR via a right mini-thoracotomy. Venous drainage was established via the right femoral vein using a 25-Fr, 55-cm HLS venous cannula with 24 side holes (BE-PVL 2555; Maquet Cardiopulmonary, Rastatt, Germany) under transesophageal echocardiographic guidance. Vacuum-assisted venous drainage was used. The guidewire was advanced toward the superior vena cava, and the cannula tip was initially considered to be positioned within the right atrium. After CPB was initiated, venous drainage became insufficient. The cannula was advanced blindly by approximately 2 cm, after which venous return improved. The valve procedure was completed uneventfully; however, pericardial bleeding became evident during volume loading before weaning from CPB. Conversion to median sternotomy revealed that the cannula had perforated the anterior free wall of the right ventricle and protruded into the pericardial cavity. The injury was repaired with a pledgeted mattress suture, and the patient recovered without further complications.

CONCLUSIONS: Adequate venous drainage during CPB does not confirm correct femoral venous cannula positioning. When venous drainage is inadequate during MICS, blind advancement of the femoral venous cannula should be avoided, and cannula position should be reassessed using multiple modalities, including TEE and fluoroscopy, when available.

INTRODUCTION: Solid papillary carcinoma of the breast is a rare papillary neoplasm with distinctive morphology and frequent neuroendocrine differentiation. However, when an invasive component is sampled in a limited core needle biopsy specimen, its solid and nested architecture may mimic invasive ductal carcinoma. We report a case of invasive solid papillary carcinoma of the breast that was initially diagnosed as invasive ductal carcinoma and was ultimately confirmed by comprehensive histopathological and immunohistochemical evaluation.

CASE PRESENTATION: A 53-year-old woman was referred to our hospital for treatment of right breast cancer detected by screening. Ultrasonography showed a 1.3-cm mass in the upper outer quadrant of the right breast. CT showed no distant metastasis, and breast MRI showed no apparent intraductal extension. The clinical stage was cT1N0M0, stage I. Core needle biopsy at the referring hospital was interpreted as invasive ductal carcinoma. Pathological review at our institution showed relatively uniform epithelial cells arranged in small nests and solid structures. The tumor was strongly positive for estrogen receptor and progesterone receptor, negative for human epidermal growth factor receptor 2, showed a low Ki-67 labeling index of 5%, and was positive for synaptophysin, suggesting invasive solid papillary carcinoma with neuroendocrine differentiation. The patient underwent breast-conserving surgery and sentinel lymph node biopsy. The resected specimen confirmed invasive solid papillary carcinoma. Postoperative Oncotype DX testing showed a recurrence score of 4. Adjuvant chemotherapy was omitted, and the patient received postoperative radiotherapy followed by endocrine therapy with anastrozole. She remains free of recurrence 1 year after surgery.

CONCLUSIONS: Invasive solid papillary carcinoma can mimic invasive ductal carcinoma on core needle biopsy. Careful morphological assessment combined with appropriate immunohistochemical evaluation is essential for an accurate diagnosis. In the present low-risk luminal case, adjuvant chemotherapy would probably not have been indicated even if the lesion had remained classified as invasive ductal carcinoma of no special type; however, preoperative recognition of this special subtype may still be clinically relevant for biopsy planning, axillary staging, surgical margin planning, and consideration of minimally invasive local treatment.

INTRODUCTION: Obturator hernia is frequently seen in thin, elderly women, and is often diagnosed following incarceration. Postoperative seroma formation is a well-recognized complication after inguinal hernia repair. In contrast, reports of seroma formation following obturator hernia repair are scarce, and its clinical features have not been well characterized.

CASE PRESENTATION: A 94-year-old woman presented with nausea and vomiting and was diagnosed with an incarcerated left obturator hernia. Manual reduction was successful and was followed by elective laparoscopic repair using the totally extraperitoneal approach with mesh placement. Although the initial postoperative course was uneventful, a large preperitoneal seroma compressing the urinary bladder developed on POD 23 and required percutaneous aspiration. The seroma subsequently became infected, necessitating repeated drainage and ultimately laparoscopic mesh removal. Despite temporary stabilization, the patient experienced sudden cardiopulmonary arrest and died postoperatively.

CONCLUSIONS: Postoperative seroma is a complication that can occur following surgery for an obturator hernia. Because obturator hernias are frequently seen in elderly patients with poor nutritional status, careful perioperative management is essential, bearing in mind that postoperative complications can have fatal consequences.

INTRODUCTION: Neoadjuvant immunochemotherapy with immune checkpoint inhibitors (ICIs) can yield atypical radiological patterns that may complicate response assessment and management decisions in curative-intent settings.

CASE PRESENTATION: A 50-year-old female with triple-negative breast cancer received neoadjuvant chemotherapy with pembrolizumab. While the primary breast tumor showed marked regression, a preexisting subpleural pulmonary nodule gradually enlarged over 6 months without respiratory symptoms or fluorodeoxyglucose uptake on PET-CT. As metastatic disease could not be excluded based on imaging alone, video-assisted thoracoscopic resection was performed. Histopathology revealed lymphocyte-predominant inflammation with hemosiderin-laden macrophages and no histological evidence of malignancy, consistent with a benign inflammatory lesion. The final pathological diagnosis was inflammatory change arising within a preexisting pulmonary bulla. The patient showed no signs of recurrence on follow-up imaging performed 1 year after breast surgery.

CONCLUSIONS: Discordant enlargement of a solitary pulmonary nodule during ICI-based therapy requires serial imaging and awareness of PET limitations for small nodules. When feasible, tissue confirmation may prevent premature abandonment of curative-intent treatment.

INTRODUCTION: Stercoral colitis caused by fecal impaction can lead to life-threatening ischemic injury of the colon. However, accurately assessing the severity and reversibility of ischemia remains challenging, particularly when determining the appropriate extent of surgical resection.

CASE PRESENTATION: We report 2 cases of stercoral colitis requiring emergency surgery. In both cases, CT demonstrated marked colonic dilatation due to fecal impaction, and intraoperative findings suggested diffuse colonic ischemia. Indocyanine green (ICG) fluorescence imaging revealed patchy hypoperfusion throughout the colon. Despite similar intraoperative findings, histopathological results differed: ischemic changes were limited to the mucosa in 1 case, whereas transmural necrosis was observed in the other. Both patients presented with severe systemic deterioration and were successfully treated with total colectomy followed by intensive postoperative management.

CONCLUSIONS: In severe stercoral colitis, the extent of histopathological ischemia does not necessarily correlate with clinical severity. Although ICG fluorescence imaging is useful for assessing bowel perfusion, it should not be used as the sole determinant of resection extent. Surgical decision-making should prioritize the overall clinical condition and the extent of colonic involvement, and extensive colectomy may be justified as a life-saving strategy in selected critically ill patients.

INTRODUCTION: Primary melanoma of the lung (PML) is exceedingly rare, accounting for approximately 0.01% of lung cancers. Because cutaneous melanoma may undergo spontaneous regression, a solitary pulmonary melanoma may represent either a true primary lesion or a metastasis from an occult regressed cutaneous primary. Therefore, rigorous exclusion of extrapulmonary primary sites is essential. PML is generally associated with a poor prognosis, and its biology and optimal management remain incompletely defined. Here, we report a case of PML with early systemic relapse after curative resection and provide a brief review of the literature.

CASE PRESENTATION: A 57-year-old woman was referred to our department (Department of General Thoracic Surgery, Osaka International Cancer Institute) for surgical management after an abnormal chest shadow was detected on routine health screening. Chest CT revealed a 2.0-cm irregular nodule in the left lower lobe with ipsilateral hilar lymphadenopathy. ¹⁸F-fluorodeoxyglucose (FDG)-PET/CT showed uptake in both lesions without evidence of disease elsewhere. Initial bronchoscopic biopsy at the referring hospital suggested a neuroendocrine tumor, whereas repeat bronchoscopic sampling at our institution raised suspicion for melanoma. Detailed dermatologic examination found no suspicious cutaneous lesions. The patient underwent open left pneumonectomy with regional lymphadenectomy; final pathology confirmed PML. Adjuvant pembrolizumab was initiated 1 month after surgery. At 4 months postoperatively, FDG-PET/CT demonstrated recurrence at the bronchial stump, mediastinal lymph nodes, pleural dissemination, and multiple systemic metastases. Combination therapy with nivolumab plus ipilimumab was administered; however, the disease progressed, and the patient died of disease 8 months after surgery.

CONCLUSIONS: This case highlights the diagnostic challenges and aggressive clinical course of PML. Thorough exclusion of extrapulmonary primary sites and comprehensive histopathologic and molecular assessment are required. Given the high risk of early systemic relapse, further investigation of multidisciplinary strategies, including perioperative systemic therapy, is warranted.

INTRODUCTION: Esophageal carcinosarcoma is a rare malignancy comprising both epithelial and mesenchymal components, for which no standard treatment has been established. Organ preservation in cervical esophageal malignant tumors is particularly challenging because curative resection often necessitates laryngectomy. We describe a cervical esophageal carcinosarcoma that responded markedly to neoadjuvant docetaxel/cisplatin/5-fluorouracil (DCF), permitting laryngeal preservation, with a brief literature context.

CASE PRESENTATION: A woman in her 50s presented with discomfort on swallowing. Upper endoscopy identified a type-1 polypoid tumor on the posterior wall 18 cm from the incisors, with involvement near the esophageal inlet at 17 cm. Biopsies showed a spindle-cell–predominant tumor; immunohistochemistry (cytokeratin AE1/AE3, p63) demonstrated an admixed epithelial component, supporting a diagnosis of esophageal carcinosarcoma. Contrast-enhanced CT revealed an approximately 6.5-cm exophytic lesion in the cervical to upper thoracic esophagus, and PET-CT showed intense uptake (maximum standardized uptake value 15.3). Clinical staging was cT3N0M0, cStage II (UICC TNM 8th edition). Two cycles of neoadjuvant DCF induced a dramatic response, leaving only a subtle ~5-mm proximal extension toward the right posterior wall. The patient underwent robot-assisted thoracoscopic subtotal esophagectomy with 3-field lymphadenectomy, followed by gastric conduit reconstruction through the posterior mediastinal route with cervical esophagogastric anastomosis using a 23-mm powered circular stapler. Intraoperative iodine staining delineated the proximal margin, and laryngeal preservation was achieved. Pathology showed pT1b-SM1, pN0, M0, pStage I with treatment-effect grade 1a, and the proximal resection margin was negative. Histology demonstrated a continuous transition between atypical squamous cells and spindle sarcomatous elements; the sarcomatous component exhibited inflammatory infiltrates predominantly composed of lymphocytes and foamy histiocytes, with focal hyalinization, consistent with a therapeutic effect. The postoperative course was uneventful, and the patient was discharged on day 16. No adjuvant therapy was administered. At 12 months of follow-up, no evidence of recurrence or metastasis has been observed.

CONCLUSIONS: This rare case illustrates that neoadjuvant DCF can downstage cervical esophageal carcinosarcoma and enable curative, larynx-preserving resection. Such responses support consideration of neoadjuvant chemotherapy as a strategy for functional preservation in selected patients with this histology.

INTRODUCTION: Carcinoembryonic antigen (CEA) is one of the most widely used tumor markers in clinical practice. In non-small cell lung cancer, elevated preoperative serum CEA levels have been reported to be associated with a poor prognosis.

CASE PRESENTATION: A 43-year-old man with primary lung cancer of the right upper lobe was referred to our hospital. Initial blood tests revealed a markedly elevated serum CEA level of 1160.0 ng/mL. Chest CT identified a 55-mm tumor in the right hilar region, with enlargement of the right hilar and prevascular (#3a) lymph nodes (c-T3N2M0, Stage IIIB according to the Union for International Cancer Control tumor–node–metastasis classification, 8th edition). The patient underwent a type A extended sleeve lobectomy and pulmonary vein transposition. However, due to suspected pulmonary venous return failure, a right completion pneumonectomy was performed on POD 7. The patient’s serum CEA levels returned to the normal range within 2 months postoperatively. He has remained recurrence-free for more than 4 years since the surgery.

CONCLUSIONS: This case highlights that upfront surgery may be a valid treatment option in selected patients with c-Stage IIIA or IIIB disease, even in the presence of an abnormally high preoperative serum CEA level.

INTRODUCTION: Esophageal carcinosarcoma (ECS) is a rare malignant tumor composed of both carcinomatous and sarcomatous components. Owing to its rarity, the clinicopathological characteristics, optimal treatment strategies, and prognostic factors of ECS remain poorly understood. This study reported the clinicopathological features and treatment outcomes of surgically treated ECS.

CASE PRESENTATION: Between 1999 and 2019, 713 patients underwent surgery for thoracic esophageal malignancies at Kurume University Hospital. Among them, 9 patients (1.3%) were diagnosed with ECS. All patients were male, with a median age of 65 years (range, 58–76 years). Preoperative endoscopic biopsy correctly diagnosed ECS in only 1 patient, while the majority were initially diagnosed as squamous cell carcinoma. Recurrence occurred in 5 patients, including local recurrence, lymph node metastasis, and distant metastasis. The 5-year overall survival rate was 22.2%, reflecting a generally poor prognosis. Histopathological examination revealed that the histological component identified at sites of lymphatic invasion in the primary tumor was consistent with those observed in metastatic lymph nodes.

CONCLUSIONS: ECS may exhibit aggressive biological behavior that is not adequately reflected by tumor depth alone. Surgery alone may be insufficient for disease control in some patients. Further studies are required to clarify the biological characteristics of ECS and to establish optimal treatment strategies.

INTRODUCTION: Pancreatic cancer (PC) is an aggressive malignancy with limited therapeutic options and generally poor responsiveness to immune checkpoint inhibitors (ICIs). Microsatellite instability–high (MSI-High) and tumor mutation burden–high (TMB-High) phenotypes are rare, each occurring in approximately 1% of PC cases, but may predict improved response to ICIs. We report a case of recurrent PC harboring both MSI-High and markedly elevated TMB, in which pembrolizumab achieved an exceptional and durable response.

CASE PRESENTATION: A 72-year-old man presented with appetite loss, and contrast-enhanced CT revealed a large pancreatic tail tumor invading the stomach, colon, spleen, and left kidney. Fine-needle biopsy confirmed adenocarcinoma. Despite initial modified FOLFIRINOX therapy showing progressive disease, subsequent gemcitabine plus nab-paclitaxel achieved partial response (PR). However, gastrointestinal bleeding due to gastric invasion necessitated surgery. The patient underwent extensive resection, including distal pancreatectomy with splenectomy, total gastrectomy, partial colectomy, nephrectomy, adrenalectomy, and portal vein resection and reconstruction using the left renal vein. Pathology demonstrated well-differentiated ductal adenocarcinoma with multiorgan invasion and portal vein tumor thrombus (ypT3N1M0, Stage IIB, Evans Grade IIb). Although adjuvant chemotherapy was considered, it could not be initiated because of persistent postoperative diarrhea and delayed recovery of the patient’s general condition. Four months after surgery, recurrence was detected in the para-aortic lymph nodes, with suspected peritoneal dissemination causing right hydronephrosis, accompanied by elevated carbohydrate antigen 19-9 (CA19-9). Comprehensive genomic profiling using the surgically resected tumor specimen revealed MSI-High status and extremely high TMB (75 mutations/Mb), and genomic alterations in MSH2, MSH3, KRAS, TP53, ARID1A, ATR, and SMAD2. Pembrolizumab was initiated, leading to rapid normalization of CA19-9 and continuous tumor shrinkage. The best overall response was classified as PR, and this PR has been maintained. At 26 months after surgery, the patient remains on pembrolizumab with sustained clinical benefit and no significant immune-related adverse events.

CONCLUSIONS: This case highlights the potential for exceptional and durable response to pembrolizumab in PC characterized by concurrent MSI-High and markedly elevated TMB. Given the rarity of these biomarkers and the typically poor prognosis of PCs, early genomic profiling may facilitate personalized treatment strategies and improve outcomes in selected patients.

INTRODUCTION: Adrenal hemangiomatous cysts are rare. Giant cysts of the right adrenal gland may be difficult to distinguish from hepatic cysts owing to their close anatomical proximity to the liver. Here, we report a case of a hemangiomatous adrenal cyst mimicking a hemorrhagic hepatic cyst.

CASE PRESENTATION: A 48-year-old woman presented with a 10-day history of abdominal pain and distention. The laboratory findings revealed marked inflammation and severe anemia. Contrast-enhanced CT demonstrated a 28-cm cystic lesion extending from the right hepatic lobe, with peripheral calcification and intralesional high-attenuation areas suggestive of a hemorrhage. A hemorrhagic hepatic cyst was initially suspected and percutaneous drainage was performed. However, the drained fluid became increasingly hemorrhagic, and anemia progressed despite repeated transfusions, indicating ongoing intracystic bleeding; therefore, exploratory laparotomy was undertaken. En bloc resection of the cyst, hepatic segment VI, and the right adrenal gland was performed. Histopathological examination revealed dilated vascular channels lined with endothelial cells that were CD34-positive and D2-40-negative and were contiguous with the adrenal cortex, confirming the diagnosis of a hemangiomatous adrenal cyst. The postoperative course was uneventful, and no recurrence was observed at 6-month follow-up.

CONCLUSIONS: Here, we report a rare case of a giant hemangiomatous adrenal cyst. Because large right adrenal cysts may be difficult to distinguish from hepatic cysts owing to their anatomical proximity, adrenal cysts should be considered in the differential diagnosis of large upper abdominal cystic lesions.

INTRODUCTION: Reversal of Hartmann’s procedure is associated with substantial morbidity, and further reduction of surgical invasiveness may be beneficial in selected patients. Perioperative anaphylaxis caused by anesthetic agents or skin antiseptics poses a significant challenge to surgical management. We report a case of stoma-site single-incision laparoscopic Hartmann’s reversal (HR) performed in a patient with severe perioperative allergies.

CASE PRESENTATION: A 73-year-old woman underwent an emergency open Hartmann’s procedure with partial cystectomy for perforated sigmoid colon cancer with bladder invasion. After adjuvant chemotherapy, she developed a progressively enlarging giant parastomal hernia that significantly impaired daily activities. Two attempts at HR were aborted because of perioperative anaphylactic shock. Subsequent allergy evaluations suggested rocuronium and chlorhexidine as causative agents, and povidone-iodine was also avoided based on clinical history. Approximately 14 months after the initial surgery, single-incision laparoscopic HR using the stoma site was successfully performed under general anesthesia without neuromuscular blocking agents. Preoperative skin antisepsis was performed using benzalkonium chloride, avoiding both chlorhexidine and povidone-iodine. No additional abdominal incisions were required. The operative time was 2 h 56 min, with minimal blood loss. The postoperative course was uneventful and she was discharged on POD 9.

CONCLUSIONS: Stoma-site single-incision laparoscopic HR may represent a useful surgical option for selected patients with severe perioperative allergies to anesthetic agents and skin antiseptics, in whom minimizing abdominal approach and wound-related risks is particularly important.

INTRODUCTION: Ampullary carcinoma is typically treated with pancreaticoduodenectomy (PD). Nevertheless, performing curative resection remains remarkably challenging when the clinical course is complicated by necrotizing pancreatitis and extensive walled-off necrosis (WON). Although resection is occasionally performed after mild pancreatitis, few reports describe curative surgery following severe necrosis requiring necrosectomy. We report a rare case managed with necrosectomy for extensive WON, followed by PD after regression of the necrotic area.

CASE PRESENTATION: A 77-year-old man presented with obstructive jaundice and underwent endoscopic retrograde cholangiopancreatography with biliary metal stent placement and biopsy, leading to a diagnosis of ampullary adenocarcinoma without distant metastasis. Shortly after the procedure, he developed acute necrotizing pancreatitis, which progressed to extensive WON surrounding the pancreatic head and body. Despite conservative treatment, the patient deteriorated due to peritonitis caused by ascending colon perforation adjacent to the necrotic area. Emergency laparotomy revealed widespread peripancreatic necrosis and colonic perforation; right hemicolectomy with ileostomy, open necrosectomy, and multiple drain placements were performed. Over the subsequent 4 months, infection control, rehabilitation, and nutritional support led to gradual regression of the necrosis, marked improvement of inflammatory markers, and no evidence of tumor progression on serial CT. Approximately 6 months after the onset of pancreatitis, a subtotal stomach-preserving PD with lymph node dissection and ileostomy closure was performed. The operation was technically demanding due to dense adhesions and fibrosis, particularly around the superior mesenteric vein. The operative time was 744 min, with an estimated blood loss of 8110 mL. Postoperative complications included a clinically relevant postoperative pancreatic fistula, bile leakage from the hepaticojejunostomy, and stenosis of the portal vein; all were managed conservatively. The patient was discharged on POD 86 and remained alive and recurrence-free 6 months later.

CONCLUSIONS: PD may be feasible in highly selected patients after clinical resolution of necrotizing pancreatitis complicated by extensive WON and colonic perforation. However, surgeons should be aware that the procedure remains highly invasive and technically demanding, even when radiologic and laboratory findings suggest resolution, and should be considered only after thorough multidisciplinary evaluation and careful counselling.

INTRODUCTION: Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare pulmonary precursor lesion that is characterized by the diffuse proliferation of neuroendocrine cells within the airway epithelium. Because obtaining a surgical specimen for histological confirmation is often difficult, management strategies for asymptomatic patients are controversial. It is generally considered an indolent condition that is often managed conservatively. However, diagnosis can be difficult in asymptomatic patients because radiological findings may resemble those of early-stage lung cancer.

CASE PRESENTATION: We present 2 cases of asymptomatic patients with DIPNECH who were detected incidentally during radiological surveillance. High-resolution CT revealed multiple pulmonary nodules in both patients, accompanied by subtle findings indicative of small-airway involvement, such as mosaic attenuation and air trapping. Despite normal laboratory findings, normal pulmonary function tests, and the absence of respiratory symptoms, serial imaging revealed slow but definite enlargement of a dominant pulmonary nodule, making it difficult to exclude malignancy with confidence. The 1st patient was a 63-year-old nonsmoking woman who was observed for multiple pulmonary nodules over 6 years. During this period, a centrally located dominant nodule in the left lower lobe gradually enlarged, prompting a diagnostic left lower lobectomy. In the 2nd case, a 51-year-old nonsmoking woman demonstrated progressive enlargement of a dominant nodule over 2 years, prompting video-assisted thoracoscopic segmentectomy. Histopathological examination in both patients confirmed DIPNECH, allowing for the exclusion of invasive malignancy and a comprehensive pathological assessment of neuroendocrine cell proliferation.

CONCLUSIONS: These cases illustrate a practical diagnostic challenge in patients with suspected DIPNECH who are asymptomatic. Although radiological surveillance is usually appropriate for indolent disease, the progressive enlargement of a dominant pulmonary nodule can limit the reliability of observation alone. Therefore, surgical resection can be justified as a diagnostic strategy within a multidisciplinary framework when malignancy cannot be confidently excluded, although careful patient selection and long-term surveillance remain essential.

INTRODUCTION: Primary cardiac angiosarcoma (PCA) is an exceptionally rare and aggressive malignant tumor characterized by a poor prognosis. Although complete surgical resection is the most effective treatment for survival, recurrence and metastasis occur frequently even after radical excision.

CASE PRESENTATION: We report a rare case of PCA in a 40-year-old woman in whom long-term survival of 68 months was achieved through aggressive multimodal therapy. She underwent urgent complete resection of a right atrial tumor, followed by preoperative chemotherapy and repeat resection with tricuspid valve replacement for recurrent disease and pulmonary metastasis. Postoperative adjuvant chemotherapy resulted in disease-free survival of 41 months. The subsequent hepatic and pulmonary metastases were managed with chemotherapy and radiotherapy before the patient succumbed to multiple organ failure.

CONCLUSIONS: Individualized, aggressive, and multimodal treatment—including repeat surgical resection and sustained systemic therapy—can achieve durable disease control and prolonged survival in selected patients with PCA, a malignancy otherwise associated with extremely poor outcomes.

INTRODUCTION: Esophageal atresia with both proximal and distal tracheoesophageal fistulas (TEF) is rare, and a proximal TEF may be overlooked during the initial neonatal surgery. However, reports describing the surgical management of residual proximal TEF beyond infancy are limited. Herein, we report a case of a residual proximal TEF that was unrecognized during neonatal repair of esophageal atresia, remained undiagnosed until adolescence, and was successfully resected using a left cervical approach.

CASE PRESENTATION: A 14-year-old boy with recurrent aspiration pneumonia was diagnosed with a residual proximal TEF and referred to our department for further management. He had a history of primary esophageal anastomosis for esophageal atresia during the neonatal period and was diagnosed with Gross type C esophageal atresia based on intraoperative bronchoscopy. He subsequently experienced recurrent aspiration pneumonia for many years. At 14 years of age, videofluoroscopic swallowing study, chest CT, and esophagogastroduodenoscopy revealed a residual proximal TEF at the level of the third thoracic vertebra (Th3). Under endoscopic guidance, a guidewire was introduced through the esophagus into the fistula and positioned within the trachea in a U-shaped configuration. Intraoperative fluoroscopy demonstrated that the fistula location corresponded to the left supraclavicular cervical region, and surgery via a left cervical approach was done. The guidewire was used to localize the proximal TEF intraoperatively by palpation and fluoroscopic guidance, and the fistula was successfully resected.

CONCLUSIONS: Even in adolescent patients with a larger body habitus, a guidewire-assisted left cervical approach is an effective surgical option for residual proximal TEF located at the Th3 level.