INTRODUCTION: The use of immune checkpoint inhibitors (ICIs) as neoadjuvant therapies for locally advanced and resectable non-small cell lung cancer is increasing. As a result, immune-related adverse events (irAEs) may be observed before surgery and may require preoperative intervention. We report the case of a patient with destructive thyroiditis induced by neoadjuvant ICI treatment, in which surgical resection was performed after steroid treatment.

CASE PRESENTATION: A 74-year-old woman was diagnosed with slow-growing squamous cell carcinoma of the right upper lobe during treatment for another disease. Imaging studies revealed a small nodule suggestive of pulmonary metastasis in the right upper lobe and hilar lymph node metastasis. The patient was initially diagnosed with primary lung cancer of the right upper lobe (cT3N1M0, Stage IIIA, TNM Classification, 8th edition), and neoadjuvant nivolumab combined with chemotherapy was planned every 3 weeks for three cycles. After the first cycle, the patient experienced drug-induced kidney injury. Nivolumab and chemotherapy were discontinued, and surgical resection was planned. However, a laboratory analysis on the day before surgery revealed elevated free triiodothyronine and free thyroxine, and decreased thyroid-stimulating hormone. Subsequent examination led to a diagnosis of destructive thyroiditis due to irAEs, and surgery was postponed. Dexamethasone was administered orally for 1 week, and once the thyroid function showed consistent improvement, a thoracoscopic right upper lobectomy was performed. The patient progressed without any other complications after surgery.

CONCLUSIONS: This report highlights a case of preoperative destructive thyroiditis secondary to irAEs. In patients receiving preoperative ICIs therapy, routine blood tests, including thyroid function tests, are recommended as part of preoperative assessment. In this case, the patient underwent lobectomy safely following steroid administration. The optimal timing of surgery in patients with preoperative ICI-induced destructive thyroiditis requires further investigation.

INTRODUCTION: Endoscopic submucosal dissection (ESD) is an effective procedure for resecting noninvasive colorectal neoplasms. However, submucosal fibrosis affects the technical difficulty of ESD. We experienced a combined ESD and transanal minimally invasive surgery (TAMIS) for a rectal neoplasm with submucosal fibrosis.

CASE PRESENTATION: We report our experience with a 75-year-old woman who had a rectal laterally spreading tumor with scarring from a prior transanal resection. She underwent combined ESD and TAMIS to overcome the procedural difficulty of ESD for submucosal fibrosis. The portion of the bowel without scarring was dissected using ESD, while the portion with scarring was dissected using TAMIS. A successful en bloc resection of the tumor was achieved, and there was no recurrence.

CONCLUSIONS: Based on the findings from this case, the combination of ESD and TAMIS may be particularly effective under conditions such as rectal neoplasms with submucosal fibrosis.

INTRODUCTION: The shortage of organ donors is a major challenge in transplantation. Expanding donor eligibility criteria can help increase the donor pool, but it is crucial to carefully assess the risks related to infections in donors with expanded criteria. Organ donation from trauma patients who have undergone open abdominal management (OAM) is uncommon because of concerns regarding organ damage and infection risk. However, with appropriate OAM and stringent infection control, safe organ donation may be possible.

CASE PRESENTATION: We herein present a case involving a patient who sustained abdominal organ injuries and head trauma from a fall. Emergency laparotomy was performed, including splenectomy for a splenic injury and liver laceration repair, followed by OAM using ABTHERA (3M Health Care, St. Paul, MN, USA). The patient subsequently developed irreversible brain damage and was declared brain dead. The patient’s family consented to organ donation. Following thorough evaluation, the heart, lungs, and liver were successfully recovered and transplanted into recipients at three different institutions, with no severe infections or rejection episodes reported.

CONCLUSIONS: This case illustrates that with proper management using ABTHERA in OAM, organ donation can be safely achieved even in challenging cases involving trauma patients.

INTRODUCTION: Insufficient blood supply to free jejunal grafts after total pharyngo-laryngo-esophagectomy (TPLE) occurs primarily due to failure of the vascular anastomosis, often resulting in rapid graft necrosis. This report details a case of ischemic enteritis caused by an arteriovenous fistula (AVF) in the mesentery of the free jejunal graft, resulting in chronic stenosis and total removal of the jejunal graft.

CASE PRESENTATION: A 61-year-old woman diagnosed with squamous cell carcinoma of the cervical and thoracic esophagus underwent TPLE with gastric conduit and free jejunal graft reconstruction. The third jejunal artery and vein were anastomosed to the left transverse cervical artery and the internal jugular vein, respectively. On postoperative day (POD) 9, leakage was observed at the free jejunal-gastric anastomosis. The fistula healed with conservative treatment but a stenosis at the pharyngeal-jejunal anastomosis developed. Endoscopic observation after balloon dilation of the stenosis showed mucosal hemorrhage and ulcer scarring in the jejunal graft. A 3D reconstructed contrast-enhanced CT revealed the presence of an AVF in the free jejunal mesentery despite well-preserved blood flow across the vascular anastomosis. As no local inflammation was observed in the neck, and oral intake was sufficient after balloon dilatation, she was discharged from hospital. Seven months after surgery, she was admitted to our hospital due to obstruction of the pharyngeal-jejunal anastomosis with cutaneous fistula. Based on the disease course and endoscopic findings of the free jejunal graft, she was diagnosed with cutaneous fistula with scarring obstruction following chronic ischemic enteritis, considered difficult to heal with conservative treatment. Total removal of the free jejunum and reconstruction with an antero-lateral femoral thigh (ALT) flap was performed at 8 months after initial surgery. Oral intake was allowed on POD13, and she was discharged in good condition on POD30.

CONCLUSIONS: We report here a rare case of late graft failure after TPLE due to chronic ischemia from an AVF in the mesentery of the free jejunal graft. Detailed assessment of mesenteric blood flow by 3D-constructed contrast-enhanced CT is useful and early removal of the ischemic jejunal graft is suggested.

INTRODUCTION: Neoadjuvant chemoimmunotherapy is increasingly regarded as the standard treatment for resectable non-small cell lung cancer. Although it improves survival outcomes, immune-related adverse events can delay or prevent curative surgery. Optimal strategies for managing these adverse events in the preoperative setting remain unclear. This case is notable for being, to the best of our knowledge, the first to report curative surgery following treatment of neoadjuvant chemoimmunotherapy-induced, steroid-refractory immune-related hepatitis using mycophenolate mofetil.

CASE PRESENTATION: A 74-year-old man with stage IIIA (cT2bN2M0) squamous cell carcinoma of the right lower lobe received neoadjuvant chemoimmunotherapy consisting of carboplatin, paclitaxel, and nivolumab. Following 2 treatment cycles, he developed fever, jaundice, and grade 3 liver dysfunction. Laboratory and imaging studies revealed features consistent with hepatitis and sclerosing cholangitis, suspected to be immune-related. High-dose corticosteroids were administered, resulting in only transient improvement. Owing to steroid-refractory disease, mycophenolate mofetil was initiated, leading to normalization of liver function and resolution of symptoms. However, the primary tumor exhibited regrowth following immunosuppression. Surgical resection was performed, consisting of right middle and lower lobectomy with lymph node dissection. Histopathology confirmed ypT1cN0M0 stage IA3 with 50% residual viable tumor. The postoperative course was complicated by persistent air leakage, empyema, and a bronchial fistula, ultimately requiring open-window thoracostomy. The patient was discharged and remains free of disease recurrence at follow-up.

CONCLUSIONS: This case highlights the potential role of mycophenolate mofetil in managing steroid-refractory immune-related liver injury induced by neoadjuvant chemoimmunotherapy in non-small cell lung cancer. Although immunosuppressive therapy may enable definitive surgery, it may also contribute to tumor regrowth and serious postoperative complications. As the use of neoadjuvant chemoimmunotherapy expands, further clinical experience is needed to guide the management of immune-related adverse events and ensure safe and effective surgical outcomes.

INTRODUCTION: Ectopic gastric mucosa (EGM) is a hyperplastic primitive gut epithelium found in tissues other than the stomach. EGM in the small intestine, distal to the ligament of Treitz (EGMdT), is uncommon. EGMdT without congenital anomalies has rarely been reported. Most reported cases are diagnosed in youth, with a single lesion and urgent symptoms requiring emergency surgery. Herein, we report a unique case of multiple EGMdTs without congenital anomalies that caused progressive ileal stenosis in an elderly patient with an observation period of 11 years.

CASE PRESENTATION: The patient was a 77-year-old man. On a medical exam 11 years before arrival at our hospital, the patient was diagnosed with EGMdT in the terminal ileum without stenosis. Five years after the initial diagnosis of EGMdT, the patient experienced his first episode of bowel obstruction, which was treated conservatively. The patient experienced three episodes of bowel obstruction, all of which were treated conservatively. The patient was then referred to our hospital for further examination and treatment. Colonoscopy at our hospital showed an EGMdT that protruded from the Bauhin’s valve. Double-balloon colonoscopy revealed a lymph follicle-like elevation 20 cm from the Bauhin’s valve with obvious stenosis. No malignancies were found on lesion biopsy. The fluoroscopic gastrointestinal series showed five lesions on the oral side of the Bauhin’s valve. Based on these findings, the patient’s symptoms were considered as the outcome of ileal stenosis caused by multiple EGMdTs; therefore, surgical resection was recommended. Laparoscopic resection of the lesion was performed. Intraoperative findings were not suspicious of malignancy. There were five erosions in the resected specimen, and all lesions were diagnosed as EGMdTs without malignancies. The patient was discharged on the 7th postoperative day without any complications. The patient had no recurrent symptoms after discharge.

CONCLUSIONS: Based on the present case, we recommend that clinicians consider surgical resection for symptomatic EGMdT, even without malignancy, and screen for multiple lesions to avoid residual EGMdT.

INTRODUCTION: Male occult breast cancers are extremely rare and often difficult to diagnose. With only few cases reported, no established treatment is available. And metastatic spread to the small intestine from a tumor originating outside the peritoneal cavity is rare. However, there is a higher tendency for metastasis to the peritoneal cavity, including the small bowel, in the case of lobular carcinoma of the breast.

CASE PRESENTATION: A 72-year-old man who initially presented with complaints of abdominal distention. Computed tomography revealed small bowel stenosis. Post-endoscopic stenosis dilatation, an emergency small bowel resection was performed for small bowel perforation. Postoperative histopathology revealed small bowel metastasis due to mammary gland lobular carcinoma with human epidermal growth factor receptor 2 (3+), estrogen receptor-negative, and progesterone receptor-negative status; the patient was then referred to our hospital. Imaging examinations revealed multiple lymph node metastases in the cervical region, right supraclavicular area, mediastinum, hilar region, and splenic portal. However, no obvious breast lesions or axillary lymph node metastases were identified, leading to a diagnosis of metastatic occult breast cancer. Complete response was achieved with trastuzumab plus pertuzumab plus docetaxel therapy; 30 months after chemotherapy initiation, multiple brain metastases were detected. Thus, 30 Gy whole-brain radiotherapy was performed followed by second-line treatment with trastuzumab emtansine. The patient died 4 years and 8 months after the disease onset, due to the progression of the disease with the new brain metastases.

CONCLUSIONS: For male occult breast cancer, it is important to understand the potential metastatic patterns and genetic factors, as well as to utilize comprehensive diagnostic methods for early diagnosis and disease management.

INTRODUCTION: While intestinal obstruction is common, intestinal endometriosis is relatively rare, making its etiology still poorly understood. We report a case of rectal obstruction caused by intestinal endometriosis with a frozen pelvis, treated with laparoscopy in collaboration with gynecologists.

CASE PRESENTATION: A 39-year-old female patient was diagnosed with rectal obstruction resulting from endometriosis with a frozen pelvis by her previous physician and subsequently treated with a transverse colon stoma for rectal obstruction and hormonal therapy for endometriosis. Unfortunately, her condition did not improve after hormonal therapy at our hospital; hence, laparoscopic low anterior resection and pelvic unclogging were performed. Regarding the extent of intestinal dissection, the rectal dissection was performed by dissecting to the point where no tissue changes were observed on the serosal side. Pathological findings revealed endometrial gland-like ducts and intimal stromal hyperplasia spanning from the serosa to the submucosa of the rectum. Her postoperative course was uneventful, leading to her discharge on postoperative day 15. The stoma was closed postoperatively, and gastrointestinal symptoms such as bowel obstruction and bleeding did not recur.

CONCLUSIONS: The extent of intestinal endometriosis preoperatively is difficult to determine accurately. Identifying the extent of bowel resection has a significant impact on the patient’s postoperative activities of daily living. Thus, carefully observing the lesion intraoperatively and resecting it at a sufficient distance from the occluding lesion are advisable.

INTRODUCTION: Pancreatico-enterostomy stenosis is a late postoperative complication following pancreaticoduodenectomy. We report a case in which a surgical “rendezvous” procedure was performed to address the stenosis.

CASE PRESENTATION: A 20-year-old woman underwent laparoscopic pancreaticoduodenectomy for a solid pseudopapillary neoplasm in the pancreatic head. During the follow-up, she presented with recurrent abdominal pain, elevated pancreatic enzymes, and dilation of the main pancreatic duct, suggestive of a remnant pancreatitis secondary to pancreaticojejunostomy stenosis. Endoscopic evaluation using double-balloon endoscopy failed to locate the anastomosis. Endoscopic ultrasound enabled puncture and cannulation of the main pancreatic duct, though the anastomotic site remained obstructed. An endoscopic nasal pancreatic drainage tube was placed within the main pancreatic duct. Subsequently, open surgery was performed to dilate the anastomosis and insert a drainage tube. A gastrotomy was created, revealing a fistula between the stomach and pancreas, and a guidewire was introduced from the fistula to the anastomosis. The guidewire was inserted through the fistula and guided to the jejunum through the anastomosis by incising the jejunum on the opposite side of the pancreaticojejunostomy. A stent was deployed across the anastomosis, and a transgastric pancreatic duct drainage was made. The patient subsequently underwent endoscopic dilation and is currently asymptomatic.

CONCLUSIONS: Symptomatic anastomotic stenosis necessitates treatment, with an endoscopic approach generally preferred as the first-line option. When endoscopic visualization of the anastomosis proves challenging, an ultrasound endoscope can be utilized to puncture the main pancreatic duct from the stomach and establish a connection to the jejunum (the “rendezvous” method). If endoscopic interventions are unsuccessful, surgical intervention is warranted. Surgical management often involves anastomotic resection and reanastomosis. In this case, a less invasive surgical “rendezvous” approach was successfully employed, which may offer a valuable surgical alternative for managing pancreatico-enterostomy stenosis after pancreaticoduodenectomy.

INTRODUCTION: Primary malignant melanoma of the esophagus (PMME) is a rare malignant tumor of the esophagus with very poor prognosis due to high rates of recurrence and metastasis even after radical resection. Recently, however, immune checkpoint inhibitors such as anti-programmed cell death-1 antibodies have been suggested to improve the prognosis of malignant melanoma. This report describes the use of postoperative nivolumab as adjuvant therapy after surgical resection of PMME, with recurrence-free follow-up for more than 1 year.

CASE PRESENTATION: A 69-year-old man had chest discomfort and tightness in his throat. Upper gastrointestinal endoscopy revealed multiple melanosis and an elevated lesion in the middle esophagus. After histological examination, he was diagnosed as having PMME, so he underwent thoracoscopic subtotal esophagectomy, three-field lymphadenectomy, pedunculated jejunum reconstruction with super-charge and super-drainage, and feeding jejunostomy due to the past history of gastrectomy. The adjuvant therapy using nivolumab (every 2 weeks, 240 mg) for 1 year was completed with no serious side effects, and there was no recurrence for more than 1 year postoperatively.

CONCLUSIONS: Although cases of PMME treated with adjuvant nivolumab have rarely been reported, the present case suggests that this approach may represent a promising treatment option, similar to cutaneous melanoma.

INTRODUCTION: Myxoid liposarcoma rarely metastasizes to the heart. Therefore, diagnosing cardiac metastases of myxoid liposarcoma is challenging, and treatment is often ineffective. Here, we report a case of cardiac metastasis from a myxoid liposarcoma detected using whole-body MRI, which was successfully treated with a multidisciplinary approach, including surgery, resulting in favorable outcomes.

CASE PRESENTATION: A 61-year-old woman had a history of pelvic myxoid liposarcoma, which was diagnosed and surgically resected at the age of 47. During follow-up, cardiac metastases were identified using whole-body MRI. The patient underwent tumor resection involving the free wall of the left ventricular apex using a cardiopulmonary bypass. The tumor had invaded the ventricular septum, creating a left-to-right shunt due to a fissure in the tumor. This necessitated a double-patch reconstruction following tumor resection. Postoperative radiation therapy was administered as adjuvant treatment. Five years after treatment, there has been no recurrence of the myocardial myxoid-type liposarcoma.

CONCLUSIONS: Complete resection of cardiac metastatic lesions from myxoid liposarcoma was achieved, resulting in favorable outcomes. Early detection of localized cardiac metastases using MRI may enable aggressive surgical interventions.

INTRODUCTION: Superior herniation of the mediastinal thymus is a rare cause of neck mass, characterized by intermittent migration of normal thymic tissue into the suprasternal region due to increased intrathoracic pressure. Generally, thymus resection is discouraged to avoid inducing athymia and subsequent immunodeficiency in the child. To date, no prior cases of tracheostomy combined with partial thymectomy have been reported. We present a case in which partial resection of the thymus was necessary to facilitate a tracheostomy.

CASE PRESENTATION: A 3-month-old female infant diagnosed with Larsen syndrome, a rare congenital connective tissue disorder, presented with respiratory failure necessitating mechanical ventilation at birth. Despite successful extubation and subsequent management with noninvasive positive pressure ventilation, she experienced recurrent episodes of apnea and oxygen desaturation. Examination revealed an anterior midline neck swelling, synchronized with respiratory movements, originating from the suprasternal notch. Ultrasound, computed tomography, and magnetic resonance imaging of the neck confirmed the presence of a normal mediastinal thymus extending into the suprasternal region. Given the risk of upper airway stenosis after the otolaryngological evaluation, an early tracheostomy under general anesthesia was planned. Upon incising the thickened cervical fascia, the thymus was visualized on the anterior surface of the trachea. The thymus and its surrounding adhesions were separated, with resection of the upper pole, followed by closure of the hernia orifice. The tracheostomy was then performed as planned. The postoperative course was uneventful, marked by gradual respiratory improvement and resolution of the intermittently visible swelling during inspiration. Cannula exchanges were completed without complications, and the patient was discharged home with a heat moisture exchanger 3 months after surgery.

CONCLUSIONS: We encountered a case of superior herniation of the normal mediastinal thymus in a patient with Larsen syndrome. While speculative, connective tissue abnormalities may contribute to this condition. In cases requiring tracheostomy, partial thymectomy and closure of the hernia orifice may be necessary to maintain fistula patency postoperatively.

INTRODUCTION: Gallbladder carcinosarcoma is extremely rare, with fewer than 100 cases reported from its first description in 1907 until 2022. Collision carcinoma is a type of synchronous carcinoma in which 2 independently arising tumors come into contact or partially invade each other.

CASE PRESENTATION: A man in his 80s was referred to our hospital with the primary complaints of weight loss and decreased appetite. Contrast-enhanced computed tomography revealed a large lobular tumor with heterogeneous enhancement, measuring 66 mm in maximum diameter, located in the fundus of the gallbladder. The mass showed clear signs of liver invasion, raising immediate concerns of malignancy. Magnetic resonance imaging provided additional crucial details. The lesion exhibited low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Notably, diffusion-weighted imaging demonstrated restricted diffusion, a characteristic often associated with malignant processes. These findings strongly suggested gallbladder cancer with liver invasion. The patient underwent cholecystectomy and hepatectomy involving segments 4, 5, and 8 of the liver. A subsequent pathological examination revealed a complex and unusual tumor composition. The hepatic lesion showed nests of varying sizes with a medullary growth pattern, which is characteristic of intrahepatic cholangiocarcinoma. In contrast, the gallbladder lesion displayed features of adenosquamous carcinoma with a partial sarcomatoid morphology, indicative of gallbladder carcinosarcoma. Intriguingly, the interface between these 2 distinct tumor types exhibited unique characteristics. In some areas, normal hepatocytes were interspersed between the 2 types of tumor cells. Other regions demonstrated an invasive tendency of tumor cells towards each other. This unusual pattern led to the diagnosis of a collision tumor, a rare occurrence in which 2 independent primary malignancies coexist in the same organ or site.

CONCLUSIONS: This was an extremely rare case of collision carcinoma involving both intrahepatic cholangiocarcinoma and gallbladder carcinosarcoma. The unique pathological findings and rarity of this tumor combination make this case particularly noteworthy. We present this case to contribute to the limited literature on such rare tumors, aiming to facilitate a better understanding and management of similar cases in the future.

INTRODUCTION: Congenital portosystemic shunt (CPSS) is a condition in which portal blood flow bypasses the liver and directly enters the systemic circulation. CPSS is often diagnosed during childhood, but it can also be incidentally diagnosed in adulthood during imaging for other conditions. Reports of surgical treatment of CPSS in adult patients are rare.

CASE PRESENTATION: A 60-year-old woman was referred to our department for further evaluation of a dilated pancreatic duct and diagnosed with ampullary carcinoma. She had a tendency toward somnolence and had taken sodium valproate for multiple seizures for 10 years. Serum ammonia level was elevated and contrast-enhanced computed tomography revealed a shunt vessel between P7 of the intrahepatic portal vein and the right hepatic vein (RHV). She was diagnosed with CPSS. Angiography showed moderate development of the intrahepatic portal system and an acceptable portal pressure increase during shunt clamping, which allows the shunt to be resected. Imaging also revealed multiple hepatic nodules with irregular shapes which was considered as focal nodular hyperplasia. Pancreatoduodenectomy (PD) with shunt closure and hepatic mass biopsy was performed. The shunt was located between P7 and RHV. The shunt was clamped at first. PD was performed while the shunt was clamped. After removing specimen, the portal pressure was 9 mmHg: this was within the acceptable range to resect the shunt. No evidence of intestinal congestion was observed, therefore the shunt vessel was closed using an automatic suturing device. On the first postoperative day, the serum ammonia level normalized. Six months after-surgery, she remained under outpatient clinic observation with no cancer recurrence. The preoperative tendency toward somnolence significantly improved.

CONCLUSIONS: We report a case of symptomatic CPSS coexisting with duodenal ampullary carcinoma. The shunt closure with simultaneous PD was feasible in this case. CPSS is recommended to treat even in adult cases because it is potentially symptomatic.

INTRODUCTION: The ileo-ileal knot is a rare condition in which 2 ileal loops form a knot, leading to obstruction, ischemia, and the need for urgent surgical intervention. It is challenging to diagnose preoperatively, with 2 closed loops on CT scan as its characteristic feature. This case revealed 3 nearly situated closed loops, which offers insights into the diagnosis and management of the ileo-ileal knot.

CASE PRESENTATION: A 69-year-old female patient presented with a 3-h history of upper abdominal pain and repeated vomiting. Contrast-enhanced CT scan revealed a poorly enhanced small-bowel obstruction, with 3 nearly situated closed loops. The patient was diagnosed with a strangulated small-bowel obstruction, likely caused by an unusual internal hernia. Emergency laparoscopic surgery was performed. Due to the difficulty in assessing the intestinal condition and the risk of injury, the procedure was converted to open surgery. Direct evaluation during laparotomy confirmed the diagnosis of an ileo-ileal knot. The knot was untied, further improving bowel color and peristalsis and allowing bowel preservation. Based on the retrospective evaluation of the reconstructed CT scan images and intraoperative findings, the 3 closed loops comprised 2 tied loops and 1 knotting loop. The patient initially recovered. However, she was readmitted on postoperative day 24 due to bowel obstruction caused by fibrosis near the terminal ileum. After undergoing ileocolic resection, the patient recovered uneventfully.

CONCLUSIONS: An ileo-ileal knot should be considered in cases of strangulated bowel obstruction with more than 2 closed loops. Because the intraoperative assessment of the knot is challenging, laparoscopic surgery can be difficult. Therefore, early conversion to laparotomy should be considered.

INTRODUCTION: Anti-MDA5 (melanoma differentiation-associated gene 5) antibody-positive dermatomyositis is a severe subtype of dermatomyositis associated with rapidly progressive interstitial lung disease, which carries an extremely high mortality rate. Prompt diagnosis and therapeutic intervention are crucial for survival. Here, we report a rare case of occult breast cancer in a patient with anti-MDA5 antibody-positive associated interstitial pneumonia. Following the control of the lung disease with immunosuppressive therapy, the patient successfully underwent neoadjuvant chemotherapy (NAC) and curative surgery.

CASE PRESENTATION: A 63-year-old woman presented with progressive dyspnea. Imaging tests revealed diffuse ground-glass opacities in both lungs and enlarged left axillary lymph nodes. Blood tests showed elevated KL-6 levels and anti-MDA5 antibodies. Although no skin lesions or myositis were observed, she was diagnosed with anti-MDA5 antibody-positive associated interstitial pneumonia. Immunosuppressive therapy, including steroid pulse therapy, tacrolimus, cyclophosphamide pulse therapy, and plasma exchange, was initiated, leading to an improvement in her lung condition. She was then initially referred to the department of plastic surgery for further evaluation of the enlarged left axillary lymph node. Excisional biopsy of the enlarged left axillary lymph node revealed triple-negative occult breast cancer (cTXN1M0, Stage IIA). After the patient was referred to our department, NAC was initiated, achieving a clinical partial response while avoiding exacerbation of the interstitial pneumonia. After completing NAC, a left axillary lymph node dissection was performed, and the final pathological diagnosis was ypTXN2aM0 (Stage IIIA). Postoperative radiotherapy was omitted due to the risk of worsening the interstitial lung disease, and capecitabine was administered for 6 months. The patient has remained recurrence-free for 3 years following treatment.

CONCLUSIONS: This case highlights the successful management of triple-negative breast cancer under the constraints of anti-MDA5 antibody-positive associated interstitial pneumonia. To ensure the smooth implementation of breast cancer treatment while controlling interstitial pneumonia, close collaboration with respiratory physicians was essential for a successful outcome.

INTRODUCTION: Perineural invasion (PNI) has been cited as an independent prognostic factor in colorectal cancer. We report the first case of an additional resection after ileocecal resection due to advanced lateral extension of PNI, with a review of the literature.

CASE PRESENTATION: A 67-year-old woman underwent colonoscopy due to positive fecal occult blood. Biopsy revealed a 20-mm type 2 tumor in the ascending colon near the ileocecal valve, which was a poorly differentiated adenocarcinoma. She underwent laparoscopic-assisted ileocecal resection and D3 dissection, and the surgery was completed routinely in which functional end-to-end anastomosis (FEEA) was performed extracorporeally. Postoperative course was good and she was discharged one week postoperatively. The pathology showed AI, type 3, 30 × 23 mm, 40%, por2>sig>tub2, pT3a (SS), int, INFb, v2, ly3, Pn1b, PM1, DM0, pN1. There was widespread cancerous extension along the intermuscular plexus within the intrinsic muscular layer of the ileum, and although grossly separated from the tumor by about 80 mm, the tumor was R1 resected with positive oral margins. Additional anastomotic resection was performed by laparotomy. Intraoperatively, the resected section was submitted to a rapid examination, which was confirmed to be negative, and the surgery was completed. The pathological examination revealed that the resected specimen showed an adenocarcinoma on the ileum side of the anastomosis, which infiltrated and proliferated within the intermuscular plexus by about 15 mm, although the tumor was not visually recognized on the resection specimen. Both bilateral margins were negative, resulting in R0 resection. Postoperative adjuvant chemotherapy was not requested by the patient. Thereafter, periodic imaging follow-up was performed and, nine months after the initial diagnosis, there was no increase in tumor markers and no evidence of recurrence on imaging.

CONCLUSIONS: Preventing R1 resection due to lateral extension of advanced PNI, which is very rare as in this case, is practically difficult given its frequency and residual bowel function. Instead, prompt additional resection and adjuvant therapy (which was not performed in this case) are essential to minimize the risk of recurrence.

INTRODUCTION: Restorative proctocolectomy with construction of an ileal J-pouch anal anastomosis is an established gold standard procedure for managing ulcerative colitis. One of the reported complications is a residual mucosal bridge as a result of leaving an apical bridge remnant when constructing the ileal J-pouch. However, now that the surgical procedure is well established, such complications rarely occur.

CASE PRESENTATION: A 12-year-old girl presented to our hospital because of anal pain. She had undergone three-stage surgery for ulcerative colitis refractory to medical therapy, the third stage (stoma closure) having been performed 1 month before the present admission. A computed tomography scan to investigate the possibility of a perianal or pelvic abscess showed no abscess, but revealed what appeared to be a thickening of the wall of the J-pouch, suggestive of pouchitis. Endoscopy revealed a mucosal bridge crossing the anterior and posterior walls of the J-pouch, with a stapler line near the posterior wall's root; however, there was no evidence of pouchitis. While creating the J-pouch (during the second stage of surgery for ulcerative colitis), we had ensured that an apical bridge was eliminated with a linear stapler. Moreover, a contrast enema of the J-pouch during the present admission demonstrated interruption of contrast in the J-pouch. These findings led us to conclude that the mucosal bridge had probably formed postoperatively, after J-pouch creation. The patient underwent endoscopic resection of the mucosal bridge in the J-pouch using an XXS wound retractor transanally. Both ends of the bridge were cut three times with a 5-mm stapler and the bridge was resected. The patient was discharged after surgery, having experienced immediate resolution of anal pain and no complications. Pathological examination of the resected specimen showed that the ileal wall had bent toward the J-pouch lumen with fibrous adherence on the serosal side, indicating that the mucosal bridge had developed unintentionally post-stoma closure. Preoperative computed tomography showed limited pouch expansion, whereas postoperative computed tomography showed sufficient expansion.

CONCLUSION: If anal pain develops following radical ulcerative colitis surgery (after ileal stoma closure), postoperative mucosal bridge formation should be included in the differential diagnosis.

INTRODUCTION: Primary cardiac tumors are rare, with malignant myxofibrosarcoma cases being particularly uncommon, while cardiac myxoma is a common diagnosis in clinical practice. We present a case of cardiac myxofibrosarcoma, whose clinical course was quite unusual.

CASE PRESENTATION: A 67-year-old woman with no prior history of cardiac tumors was admitted for dyspnea and was found to have a 60 mm tumor in the left atrium. Despite initial resection, the tumor recurred twice, and a subsequent pleural mass biopsy revealed metastasis of myxofibrosarcoma. Retrospective analysis confirmed that the pathological findings of all the resected tumors were consistent with myxofibrosarcoma. Chemotherapy with doxorubicin was initiated, but severe side effects led to its discontinuation. The tumors continued to grow, causing significant pain, and she passed away a year later.

CONCLUSIONS: The differential diagnosis of cardiac myxofibrosarcoma is challenging due to its similarity to benign myxomas. Accurate diagnosis requires thorough histological and immunohistochemical evaluation is essential.

INTRODUCTION: Spontaneous esophageal rupture is a rare but life-threatening condition with a high mortality rate. While conservative and endoscopic therapies have been reported, surgical treatment remains essential. The optimal approach involves esophageal defect repair and mediastinal drainage, which is performed via laparotomy, thoracotomy, laparoscopy, or a combination of these techniques. We report a case of laparoscopic intramediastinal omental filling for a spontaneous esophageal rupture that was challenging to close.

CASE PRESENTATION: A 62-year-old man presented with sudden-onset right-sided abdominal pain. Computed tomography and esophagography revealed a spontaneous rupture of the right wall of the lower esophagus. Laparoscopic surgery was performed 4 h following symptom onset. A partially necrotic area was identified in the lower esophagus. Given the difficulty of suturing the necrotic esophageal wall, the mediastinum was filled with the greater omentum to cover the perforation site. The patient had no significant postoperative complications and was discharged on the 24th postoperative day.

CONCLUSIONS: Laparoscopic omental filling repair is a viable option for esophageal rupture when primary suture closure is not feasible.

INTRODUCTION Postoperative lymphatic fistula is a relatively rare complication of abdominal and pelvic surgery. Lymphatic fistula is classified based on whether it contains lymphatic ascites with clear lymphatic fluid from the lumbar lymphatic trunks or chylous ascites with milky chyle fluid from the intestinal lymphatic trunk. These two lymphatic trunks eventually converge into the cisterna chyli, which is located at vertebrae T10–L3. In cases of lymphatic fistula following lymphadenectomy in this region, lymphatic leakage from either the intestinal or lumbar lymphatic trunk, or both, should be suspected. Here, we report the successful treatment of a refractory lymphatic fistula after para-aortic lymphadenectomy for rectal cancer by visualizing intestinal lymphatic leakage using enteral high-fat milk and lumbar lymphatic leakage using inguinal intranodal lymphangiography with indocyanine green (ICG).

CASE PRESENTATION: A 57-year-old male developed chylous ascites with elevated triglyceride levels after para-aortic lymphadenectomy. Conservative treatments, including dietary management with fasting, total parenteral nutrition, and administration of octreotide, were ineffective. Although lymphangiography with lipiodol identified lumbar lymphatic leakage, it failed to stop the lymphatic fistula. The intestinal lymphatic leakage site detected by enteral high-fat milk was sutured laparoscopically, and the lumbar lymphatic leakage site was glued with a fibrin sealant patch. However, persistent lymphatic leakage required repeated abdominal paracentesis. Open suturing of the lymphatic leakage site was performed using navigation with ICG and high-fat milk to resolve the lymphatic fistula completely. Lymphatic leakage from the intestinal lymphatic system was detected using enteral high-fat milk and from the lumbar lymphatic trunk using inguinal intranodal lymphangiography with ICG. A total of 5 mL of ICG (1.25 mg/mL) was injected into the inguinal lymph node. ICG leakage was identified at the lumber lymphatic trunk. The leakage site was sutured until the leakage disappeared. Four months after surgery, the ascites disappeared utterly.

CONCLUSIONS: This case demonstrates the efficacy of combining enteral high-fat milk and inguinal intranodal lymphangiography with ICG for accurate detection and differentiation of lymphatic leakage sources. Our dual lymphangiography technique aids in distinguishing leakage from either the intestinal lymphatic or lumbar lymphatic systems, which is critical for the successful treatment of complex lymphatic fistula.

INTRODUCTION: Persistent left superior vena cava (PLSVC), which is asymptomatic and occurs in 0.3%–0.5% of the general population, is typically detected incidentally but can complicate cardiac procedures owing to its potential to cause arrhythmias. This condition involves an additional venous return pathway to the right atrium, which can alter the cardiac anatomy and is associated with other cardiac aortic anomalies.

CASE PRESENTATION: A 75-year-old male patient required a central venous port for chemotherapy and radiation therapy for mid-thoracic esophageal cancer. Preoperative computed tomography images revealed that the PLSVC ran ventrally to the aortic and left pulmonary arteries, directly communicating with the right atrium. A peripherally inserted central catheter (PICC) port was planned. The catheter tip of the PICC port was placed within the left superior vena cava instead of the more common right superior vena cava, because the appropriate vessels could not be identified in the right upper arm. This anomaly necessitated a review of findings on the preoperative imaging and underscored the importance of early detection through echocardiography and radiographic guidance to prevent procedural complications. Reconstructed three-dimensional images and radiography-guided catheterization support the navigation of PICC port insertion.

CONCLUSIONS: PLSVC, which is often asymptomatic, requires careful preprocedural planning and imaging to ensure safe PICC port insertion.

INTRODUCTION: Mesothelioma arises from mesothelial cells. This tumor is very rare among pediatric abdominal neoplasms. We herein report an extremely rare case of acute abdomen with cystic mesothelioma of the peritoneum in a child.

CASE PRESENTATION: A 14-year-old boy was referred to our hospital for emergency surgery. Surgery revealed a primary tumor arising from the greater omentum. The tumor was macroscopically diagnosed as a benign omental lymphangioma and was resected en bloc with the greater omentum. A histopathological examination of the tumor revealed a simple columnar epithelium-like mesothelioma with poor cell-atypia. Immunohistochemical examination showed antibody reactivity in the cyst epithelium, including an anti-calretinin antibody. The final pathological diagnosis was a mesothelioma originating from the peritoneum.

CONCLUSIONS: In pediatric cases diagnosed with cystic lymphatic malformation, the possibility of peritoneal mesothelioma needs to be considered and carefully confirmed or ruled out.

INTRODUCTION: Recurrent tumors in colorectal cancer may be removed along with adjacent blood vessels to achieve R0 resection. However, it remains unclear whether to aggressively perform this procedure because it may cause serious intraoperative or postoperative complications.

CASE PRESENTATION: In Case 1, a 62-year-old man underwent radical surgery for rectosigmoid cancer. Three years later, computed tomography scans revealed a disseminated nodule near the left external iliac vessels. We resected the tumor and vessels that were reconstructed by bypass surgery. Histologically, the margins of the tumor were in contact with the adventitia of the vessels. In Case 2, a 63-year-old man underwent radical surgery for ascending colon cancer. A nodule was detected at the right iliac fossa 16 years later and appeared to invade the right femoral vessels. After systemic chemotherapy, the nodule was removed with partial resection of the right femoral artery and vein that were reconstructed by end-to-end anastomosis and bypass surgery, respectively. Histologically, the tumor was located 0.7 mm from the vessels. In Case 3, a 67-year-old woman underwent radical multivisceral resection for obstructive rectosigmoid cancer invading the adjacent organs. Fifteen months later, she developed local recurrence and subsequently received chemotherapy. She underwent en bloc resection of the tumor and the left internal iliac artery (IIA) near the bifurcation. The left external iliac artery was reconstructed by end-to-end anastomosis. Direct invasion of the IIA was proven histologically. In Case 4, a 74-year-old woman underwent radical surgery for ascending colon cancer with high microsatellite instability. Eight months later, a recurrent tumor was detected near the right external iliac vessels. After pembrolizumab and chemoradiotherapy, we resected the tumor and part of the external iliac vein; the defect was primarily closed with sutures. No viable tumor cells were found in the specimen. During the follow-up period (median: 52 months), 3 patients were alive without vascular surgery-related complications.

CONCLUSIONS: It is difficult to accurately evaluate whether a recurrent tumor from colorectal cancer directly invades vessels using preoperative imaging. However, the combined resection of recurrent tumor and vessels may be required to achieve R0 resection, considering a short distance even in invasion-negative cases.

INTRODUCTION: Cholangiolocarcinoma (CLC) with ductal plate malformation (DPM) is a rare primary liver cancer originating from the canals of Hering. It often exhibits intermediate behavior between hepatocellular carcinoma and intrahepatic cholangiocarcinoma. Diagnosing CLC with DPM is challenging due to overlapping imaging features with other liver malignancies.

CASE PRESENTATION: An 82-year-old man under surveillance for bladder cancer was incidentally found to have a liver nodule in segment 8. Over 6 years, the lesion grew from 10 mm to 41 mm and showed dynamic changes on imaging. Despite two inconclusive biopsies, a diagnosis of CLC with DPM was confirmed after a third biopsy and consultation with a specialized institution. The patient underwent a right hepatectomy, and pathological examination confirmed CLC with DPM. No evidence of recurrence was observed 19 months post-surgery.

CONCLUSIONS: This case underscores the importance of long-term follow-up and a multidisciplinary approach in managing rare hepatic malignancies. The clinical course provides valuable insights into the progression of CLC with DPM and may aid in diagnosing similar challenging cases.

INTRODUCTION: Segmentectomy is being accepted as a valid operative procedure for small peripheral non-small cell lung cancer. Understanding pulmonary artery (PA) variations is essential to ensure safe and reliable surgeries. Herein, we report a case of left S3 and S8 segmentectomy involving a complete interlobar branch of the left A3, a relatively rare anomaly reported in less than 0.56% of cases in previous studies.

CASE PRESENTATION: A woman in her sixties was referred to our hospital with two nodules in the left upper lobe anterior segment (S3, 1.1 × 0.8 cm) and the lower lobe anterior basal segment (S8, 1.8 × 1.7 cm), suggestive of double primary lung cancer. Preoperative thin-slice computed tomography (CT) and three-dimensional CT revealed a vascular anomaly in which the entire left A3 branched from the interlobar PA. Left S3 and S8 segmentectomies were performed via thoracotomy. The interlobar A3 branched at nearly the same level as the A6. After cutting the V3b and V3c veins, the intersegmental plane and the interlobar A3 were sequentially divided using staplers. To prevent torsion of the remaining lung, the edges of the apico-posterior segment (S1+2) and the lingular segment were loosely secured with silk sutures. The operative times were 4 h and 8 min with minimal blood loss. Pathological examination revealed that both nodules were squamous cell carcinomas of the lungs (pT1bN0M0, pStage IA2). The patient remained recurrence-free for over 1 year.

CONCLUSIONS: Complete interlobar branching of the left A3 is uncommon. During left S3 segmentectomy in cases involving an interlobar A3, the S1+2 and lingular segments may become solitary blocks, necessitating measures to prevent torsion.

INTRODUCTION: Surgical resection remains the gold standard for managing mediastinal cysts, including bronchogenic cysts, whereas needle aspiration serves as an alternative option that can facilitate preoperative volume reduction or, in certain selected cases, serve as a definitive treatment. However, it may lead to rare but potentially life-threatening complications such as mediastinitis; therefore, its indication should be carefully considered. This report details a case of a delayed intracystic hemorrhage 3 days after an endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), requiring emergency surgery with venoarterial extracorporeal membrane oxygenation (V-A ECMO) on standby, which was successfully managed using a confronting upside-down video-assisted thoracoscopic surgery (VATS) approach.

CASE PRESENTATION: A 64-year-old woman with exertional dyspnea was diagnosed with a superior mediastinal cyst compressing the trachea and esophagus. Preoperative EUS-FNA was performed to reduce the cyst volume and any mitigate potential complications during anesthesia induction. Three days later, she developed dyspnea due to a delayed intracystic hemorrhage, necessitating emergency surgery. VATS with a confronting upside-down monitor setup was performed under standby V-A ECMO. Despite a limited surgical field under 2-lung ventilation, a confronting upside-down VATS approach allowed sufficient visualization and maneuverability. The patient had an uneventful recovery, with no recurrence at 3 months.

CONCLUSIONS: A delayed intracystic hemorrhage is a potential risk following an EUS-FNA for mediastinal cysts. A confronting upside-down VATS approach provides sufficient maneuverability even for superior mediastinal tumors, despite a limited surgical field due to inadequate 1-lung ventilation. Placement of the camera port in the higher intercostal space was deemed particularly crucial.

INTRODUCTION: Heterotopic pancreas refers to pancreatic tissue located outside its normal position and lacking anatomical or vascular continuity with the pancreas. Gastric heterotopic pancreas (GHP) is generally asymptomatic, but in rare cases large GHP lesions can cause gastric outlet syndrome or gastroduodenal invagination. GHP may also occasionally cause acute pancreatitis and abscess formation in the gastric wall. This report describes a rare case of GHP with concurrent gastroduodenal invagination and gastric wall abscess treated via laparoscopic distal gastrectomy.

CASE PRESENTATION: A 46-year-old man was admitted to the hospital with abdominal pain and vomiting. Computed tomography revealed a 40-mm low-density mass in the gastric pylorus, and gastroduodenal invagination. Gastroscopy confirmed a submucosal lesion at the gastric pylorus causing pyloric stenosis. The patient underwent laparoscopic distal gastrectomy with Roux-en-Y reconstruction. Histopathological examination revealed a gastric submucosal lesion containing pancreatic tissue with acinar cells and ducts, without islets of Langerhans, leading to a diagnosis of Heinrich type II GHP. The submucosal lesion also contained inflammatory components such as neutrophils and foamy histiocytes, forming a gastric wall abscess. Finally, the patient was discharged on postoperative day 11 and is progressing well 7 months after surgery.

CONCLUSIONS: Herein we report the first case of laparoscopic distal gastrectomy for GHP with concurrent gastroduodenal invagination and gastric wall abscess resulting in a favorable outcome.

INTRODUCTION: Adult intussusception is rare, accounting for approximately 5%–16% of all cases. Unlike pediatric intussusception, which is predominantly idiopathic, most adult cases are associated with organic lesions, nearly half of which are malignant. Idiopathic intussusception without a lead point is uncommon but appears to be increasingly recognized. We report a case of idiopathic adult ileocolic intussusception that mimicked cecal carcinoma in imaging studies.

CASE PRESENTATION: A 63-year-old male with a history of gastric cancer recurrence presented with a 3-month history of abdominal pain. Contrast-enhanced computed tomography (CT) revealed circumferential thickening of the right colon, forming a “target sign,” and invagination of the ileocecal region into the right colon, suggesting ileocolic intussusception. Colonoscopy identified a nodular lesion presumed to be cecal carcinoma; however, the biopsy did not provide a definitive diagnosis of malignancy. Preoperative ¹⁸F-fluorodeoxyglucose-positron emission tomography (¹⁸F-FDG-PET/CT) revealed high FDG uptake at the leading edge of the intussusception; however, no findings indicative of metastatic disease were observed. The patient underwent elective surgery, and a right colectomy with lymph node dissection was performed. However, the intussusception was found to have spontaneously resolved at laparotomy. Histopathological examination showed mild intramural congestion in the ileocecal valve. Postoperative imaging confirmed the absence of any lead point lesion, resulting in a final diagnosis of idiopathic intussusception.

CONCLUSIONS: This case highlights the diagnostic limitations of CT and PET/CT in evaluating lead points in adult intussusception, as false-positive findings are common. Given the possibility of spontaneous resolution, a conservative approach, including repeat imaging immediately before surgery, may be suitable in select cases of adult intussusception.

INTRODUCTION: Pembrolizumab has been introduced to solid cancers with microsatellite instability (MSI)-high cases; however, its clinical experience for cholangiocarcinoma remains very limited. Here, we present a case who successfully underwent conversion surgery following pembrolizumab treatment for MSI-high perihilar cholangiocarcinoma, which pathologically exhibited complete response.

CASE PRESENTATION: A 69-year-old male with Bismuth IV perihilar cholangiocarcinoma with bulky lymphadenopathy was referred, who initially required left hepatic trisectionectomy, caudate lobectomy, bile duct resection, and portal vein resection and reconstruction (H123458-B-PV). During the waiting period after preoperative portal vein embolization, the right hepatic artery was involved by rapid tumor progression, needing a modification of the initially scheduled surgical procedure to additional hepatic artery resection and reconstruction (H123458-B-PV-HA). We revised the surgical decision of resectable to locally unresectable disease. He received systemic chemotherapy with gemcitabine and cisplatin as first-line, showing the best effect of stable disease followed by slight tumor progression and re-elevation of tumor marker after 5 courses of treatment. Cancer multi-gene panel analysis using percutaneous biopsy specimen showed the nature of MSI-high. Therefore, he received pembrolizumab treatment as second-line therapy, leading to a drastic downsize >30% in tumor diameter and normalization of the tumor marker as well after only 2 cycles of administration. After confirmation of keeping tumor shrinkage during 22 courses of pembrolizumab treatment without any severe adverse events, we decided to perform conversion surgery and performed left trisectionectomy, caudate lobectomy, and bile duct resection with portal vein resection (H123458-B-PV). Although the right hepatic artery was extensively fibrotic, there was no evidence of malignancy by frozen section histologic diagnosis. The pathological findings showed pathological complete response with no residual tumor cells. The patient is under periodical checkup without adjuvant chemotherapy, and no tumor recurrence was observed at 4 months postoperatively.

CONCLUSIONS: We experienced clinical partial response but pathological complete response after second-line pembrolizumab treatment for unresectable locally advanced perihilar cholangiocarcinoma with a biologic nature of MSI-high. Conversion surgery may be considered as a promising option for such effective case, whereas there is a possibility to avoid resection in the MSI-high setting.

INTRODUCTION: Colorectal cancer is a prevalent malignancy that necessitates personalized chemotherapy, especially with the advent of molecular-targeted drugs and immune checkpoint inhibitors. In Japan, immune checkpoint inhibitors have been approved for unresectable advanced and recurrent colorectal cancer; however, their use in preoperative therapy for colorectal cancer has not yet been approved. Globally, neoadjuvant immunotherapy has demonstrated promising outcomes in colorectal cancer cases with high immunogenicity, including microsatellite instability-high and deficient mismatch repair.

CASE PRESENTATION: We report a case of a microsatellite instability-high, clinically unresectable, locally advanced ascending colon cancer treated with immune checkpoint inhibitors, which showed significant tumor shrinkage, facilitating standard surgery while avoiding adjunct organ resection. The patient, a 70-year-old male, experienced chronic abdominal pain and diarrhea. Lower gastrointestinal endoscopy and computed tomography confirmed a diagnosis of ascending colon cancer with suspected invasion into the descending duodenum. Although curative resection was technically feasible with pancreatoduodenectomy, neoadjuvant chemotherapy was selected to reduce tumor size, considering the patient’s overall condition. Companion diagnostics revealed microsatellite instability-high status and BRAF^V600E mutation, leading to the initiation of chemotherapy combined with an immune checkpoint inhibitor (pembrolizumab). Subsequently, prolonged pembrolizumab administration was challenging due to suspected immune-related adverse events, including diarrhea and pruritus. However, significant tumor reduction was observed during a follow-up computed tomography scan, facilitating surgery approximately 6 months after treatment initiation. The perioperative period was uneventful, and the patient was discharged on the eighth day after operation. The final pathological results revealed complete tumor disappearance (histological effect of chemotherapy: Grade 3).

CONCLUSIONS: This case highlights the potential of neoadjuvant immunotherapy in reducing surgical invasiveness in patients with colorectal cancer.

INTRODUCTION: Chylothorax following esophagectomy is a relatively rare but significant complication, with incidences ranging from 1.1% to 3.8%. It typically arises from damage to the thoracic duct or associated lymphatic vessels during extensive lymph node dissection and thoracic surgery. Initial management usually relies on conservative approaches such as dietary modifications, drainage, and pharmacotherapy. If these methods are ineffective, surgical intervention becomes necessary. However, standardized guidelines for the optimal management of thoracic duct injuries are as yet lacking, with decisions made on a case-by-case basis. We describe a case of chylothorax following esophagectomy where lymphangiography played a crucial role in guiding the surgical approach.

CASE PRESENTATION: We report the clinical course of a 72-year-old male who developed chylothorax following esophagectomy for recurrent esophageal cancer. Despite initial conservative management, including octreotide and total parenteral nutrition, the patient’s condition required further intervention. Lymphangiography performed on postoperative day (POD)14 revealed a rare anatomical variation of the thoracic duct, leading to successful surgical ligation through a right cervical approach. The patient’s postoperative course was complicated by mediastinal fluid accumulation and resultant cardiac tamponade, necessitating emergency mediastinal drainage. Following the targeted surgical intervention, the drainage volume decreased, and the patient gradually resumed oral intake after swallowing function training. He was discharged on POD118.

CONCLUSIONS: Thoracic duct injury after esophagectomy is challenging, especially with anatomical variations. Lymphangiography enables precise localization, guides surgery, and improves outcomes in chylothorax patients. The literature confirms that its early use reduces hospital stays and complications. Tumor invasion or inflammation at or beyond T3 may increase surgical complexity and injury risk. Given its diagnostic and therapeutic benefits, lymphangiography should be integrated into the standard protocols for chylothorax, especially in cases in where conservative treatment fails or anatomical variations are suspected.

INTRODUCTION: When a thrombus extends to the suprahepatic inferior vena cava (IVC) in patients with Budd–Chiari syndrome (BCS) requiring liver transplantation (LT), there is a risk of thrombus migration during hepatectomy that can potentially lead to pulmonary embolism. Intraoperative pulmonary embolism can be life-threatening and may necessitate urgent thrombectomy. However, preventive strategies for pulmonary embolism during LT in BCS cases with IVC thrombosis have seldom been discussed in the literature. We report a case involving a 51-year-old woman with BCS complicated by thrombi extending into the suprahepatic IVC who underwent deceased donor LT (DDLT) for acute liver failure (ALF).

CASE PRESENTATION: A previously healthy 51-year-old woman with ALF secondary to BCS was admitted to our hospital. 19 days back, BCS was diagnosed at another hospital, where computed tomography revealed thrombi in the hepatic veins and IVC. She subsequently developed grade II hepatic encephalopathy and severe liver dysfunction. Conservative treatment was ineffective, and 4 days before the current admission, she experienced grade III hepatic encephalopathy and showed hepatofugal portal flow on ultrasonography. DDLT was performed on day 13 after admission. Median sternotomy was performed to clamp the suprahepatic IVC near the right atrium, mitigating the risk of thrombus migration during hepatectomy and allowing for urgent thrombectomy in case of pulmonary embolism. Additionally, because a large-for-size graft was being used, the median sternotomy enhanced visibility and provided adequate space, facilitating suprahepatic IVC anastomosis. Postoperatively, the patient experienced no complications related to the sternotomy and was discharged 58 days after surgery.

CONCLUSIONS: This case report highlights the potential utility of median sternotomy during LT for BCS, particularly for cases with concerns regarding thrombus migration from the suprahepatic IVC, the need for rapid thrombectomy in the event of pulmonary embolism, and anticipated challenges in suprahepatic IVC anastomosis due to large-for-size grafts.

INTRODUCTION: Splenic abscess is a rare but potentially life-threatening condition that can rupture, leading to pneumoperitoneum and symptoms that mimic gastrointestinal perforation in rare cases. This can significantly complicate accurate diagnosis and prompt treatment. A splenic abscess can become life-threatening by rupturing, which may cause diffuse peritonitis or sepsis.

CASE PRESENTATION: A 68-year-old man with uncontrolled diabetes presented with fever, chills, and abdominal pain. Initial evaluation at a previous hospital, including computed tomography (CT), suggested a lower gastrointestinal perforation, leading to his transfer to our facility. CT revealed a non-enhancing lesion with gas in the spleen and free intraperitoneal air; however, there was no clear evidence of gastrointestinal perforation. An emergency exploratory laparotomy was performed, which revealed purulent ascites and a ruptured splenic abscess without any gastrointestinal perforation. After thorough lavage to eliminate contamination, open abdominal management was initiated owing to a need for catecholamine support and an inability to completely rule out the possibility of gastrointestinal perforation. A second-look laparotomy confirmed that there was no further contamination or gastrointestinal tract perforation. Blood and abscess cultures revealed Escherichia coli, leading us to initiate targeted antibiotic therapy. The patient recovered successfully and was discharged on postoperative day 40 without any recurrence. Ruptured splenic abscess with pneumoperitoneum is rare and poses significant diagnostic challenges, particularly in patients with diabetes, owing to its clinical similarity to gastrointestinal perforation. This study highlights the utility of exploratory laparotomy and staged open abdominal management when gastrointestinal perforation cannot be ruled out.

CONCLUSIONS: Physicians should consider ruptured splenic abscesses in patients with pneumoperitoneum, particularly those with diabetes. Exploratory laparotomy with staged open abdominal management may represent an effective approach that facilitates safe monitoring and targeted treatment, thereby reducing the risk of fatal complications.

INTRODUCTION: Adult pancreatoblastoma (PB) is an extremely rare malignant pancreatic epithelial tumor. Although no standard treatment strategy has been established, complete resection is recommended for long-term survival. Here, we presented a case of an adult patient with PB who successfully underwent complete resection via robotic surgery. Furthermore, this is the first report of robotic surgery for PB, highlighting its novelty and potential clinical relevance.

CASE PRESENTATION: A 40-year-old man presented with epigastric pain, and image examination revealed a well-defined tumor in the pancreatic tail extending into the main pancreatic duct (MPD) and reaching the pancreatic neck. With no evidence of distant metastases, surgery was planned following 2 courses of gemcitabine and S-1 chemotherapy for tumor shrinkage. There were no significant changes in the tumor’s extension after chemotherapy, but no new lesions appeared, and robotic distal pancreatectomy was performed. Intraoperative findings confirmed the tumor extension into the MPD just above the superior mesenteric vein (SMV). The pancreas was sharply divided at the right edge of the SMV, and a negative transection margin was obtained. The pancreatic stump was closed by suture. The postoperative course was uneventful, and the pathological diagnosis confirmed PB with MPD and inferior mesenteric vein invasion.

CONCLUSIONS: We successfully resected an adult case of PB with tumor extension into the MPD via robotic surgery. Robotic surgery enabled precise pancreatic transection at the right edge of the SMV, ensuring a negative pancreatic transection margin in this case. In addition, robotic surgery contributed to the safe and secure suture closure of the pancreatic stump.

INTRODUCTION: Hepatocellular carcinoma (HCC) often requires repeated therapy and poses challenges in treatment selection, particularly in patients with impaired liver function. Although hepatic resection, radiofrequency ablation, and liver transplantation are standard local curative therapies, the position of radiotherapy, including proton beam therapy (PBT), remains relatively underexplored. Herein, we report an illustrative case of unresectable HCC treated with spacer placement surgery using a bioabsorbable spacer, followed by PBT.

CASE PRESENTATION: We report the case of a 77-year-old male patient diagnosed with a 6 cm HCC in segment 8, accompanied by impaired liver function, precluding hepatic resection. PBT was planned; however, because of the proximity of the gastrointestinal tract to the tumor, spacer placement was deemed necessary, and a bioabsorbable polyglycolic acid spacer was placed, followed by PBT. Owing to the sufficient space provided by the spacer, curative doses of PBT could be delivered to the tumor, and the patient survived for 26 months after spacer placement surgery without any sign of recurrence.

CONCLUSIONS: Bioabsorbable spacer placement surgery and subsequent PBT are feasible and promising treatment options for unresectable HCC with impaired liver function.

INTRODUCTION: Herein, we report a patient who underwent stent-graft implantation using the retrograde approach for a renal artery aneurysm.

CASE PRESENTATION: The patient was a 48-year-old man who underwent total arch replacement, thoracoabdominal aortic repair, aortic root replacement, and thoracic endovascular aortic repair for Marfan syndrome. A right renal artery aneurysm developed at the prosthetic graft anastomosis during observation. First, stent-graft implantation using the antegrade approach was performed. However, the delivery system could not be advanced to the right renal artery because of prosthetic graft kinking. Therefore, the procedure was discontinued. Next, the retrograde approach was used. A right hypochondral oblique incision was made. The right renal artery was exposed with the retroperitoneal approach, and a stent graft was retrogradely inserted into the renal artery and deployed between the prosthetic graft and the distal right renal artery to cover the aneurysm. The patient was followed up for 3 years after the surgery, and he did not develop any aneurysm.

CONCLUSIONS: Renal artery stent graft implantation using the retrograde approach can be a treatment option for renal artery aneurysms in patients with a hostile abdomen.

INTRODUCTION: Hepatic epithelioid hemangioendothelioma (HEHE) is a rare vascular tumor. Treatment strategy remains controversial because of its rarity. Liver resection is considered as the optimal treatment for solitary HEHE, while a small subset of patients have a solitary tumor. We present the rare case of a patient with solitary primary HEHE who experienced solitary recurrence following liver resection and underwent subsequent liver resection.

CASE PRESENTATION: A 55-year-old man was referred to our department with a suspected intrahepatic cholangiocarcinoma, based on imaging findings. Anatomic liver resection of segment 8 was performed, and the tumor was confirmed to be HEHE from the pathological findings. Fifteen months later, a solitary recurrence developed in segment 7. After a 5-month observation period, partial liver resection was performed, and the tumor was consistent with recurrent HEHE. The postoperative course was uneventful, and the patient remained recurrence-free for 9 months following the procedure.

CONCLUSIONS: Repeat liver resection may be a feasible treatment option for patients with solitary recurrent HEHE.

INTRODUCTION: Bioprosthetic valve failure after mitral valve replacement is a well-recognized phenomenon, with pannus overgrowth being one notable cause. The standard treatments include redo surgical mitral valve replacement and the less invasive transcatheter treatment, mitral valve-in-valve. However, the feasibility and safety of performing mitral valve-in-valve when pannus overgrowth has reduced the valvular opening to a mere pinhole remains uncertain.

CASE PRESENTATION: A 76-year-old woman, who had previously undergone mitral valve replacement, was admitted for congestive heart failure. Severe mitral stenosis and severe mitral regurgitation were diagnosed using transthoracic echocardiography. During redo mitral valve replacement, we observed that the prosthetic valve leaflets on the left atrial side were almost entirely covered with pannus tissue, leaving only a central pinhole for blood flow. Macroscopic and microscopic examination of the bioprosthesis revealed accordion-like leaflet deformation on the ventricular side.

CONCLUSIONS: Although the transcatheter valve-in-valve procedure is recognized as a less invasive treatment option for degenerated biological valves, in certain cases such as ours, open surgery becomes imperative as the most appropriate treatment.

INTRODUCTION: Obturator hernias are rare, accounting for 0.05%–1.4% of all hernias, and typically affect elderly, thin women. Bladder hernias, though uncommon, comprise 1%–4% of groin hernias, with bladder herniation through the obturator foramen being extremely rare. We report a case of an obturator hernia involving the urinary bladder, which was incidentally discovered during femoral hernia repair.

CASE PRESENTATION: A 70-year-old woman presented with a 2-day history of abdominal pain and vomiting. She had no urinary symptoms. Abdominal computed tomography (CT) revealed a right femoral hernia and an unexpected bladder herniation through the obturator foramen. Laparoscopic transabdominal preperitoneal (TAPP) repair was performed using 3 ports. The incarcerated bowel was reduced after incising the lacunar ligament. The prolapsed bladder was carefully dissected to prevent injury, and a dual-layered Bard mesh (Medicon, Franklin Lakes, NJ, USA) was placed to reinforce the defect. The patient recovered uneventfully and was discharged on the 7th postoperative day. No recurrence or urinary symptoms were observed several months postoperatively.

CONCLUSIONS: Bladder herniation through the obturator foramen is extremely rare and often asymptomatic, making preoperative diagnosis challenging. Surgeons should consider this condition during hernia repair to prevent intraoperative bladder injury. Preoperative imaging is crucial for safe and complete surgical management.

INTRODUCTION: Obstructive jaundice is often the first symptom of ampullary carcinoma, with a straightforward preoperative diagnosis. We report a rare case of ampullary carcinoma without jaundice as the initial symptom.

CASE PRESENTATION: A 53-year-old man was admitted with abdominal distension and recurrent vomiting. Esophagogastroduodenoscopy revealed a complete duodenal obstruction without malignant findings. Computed tomography revealed wall thickening in the second portion of the duodenum. The common bile duct and main pancreatic duct were not dilated. As there was no evidence of malignancy, we performed gastrojejunostomy as a bypass to improve the symptoms. Five months later, follow-up blood examinations showed elevated total bilirubin levels, and computed tomography revealed persistent thickening of the duodenal wall with exacerbated dilation of common bile duct and main pancreatic duct. Mucosal biopsies from the oral and anal sides of the stenosis revealed no malignancy. Due to a strong suspicion of malignant disease and difficulty in preoperative biliary drainage, we performed pancreatoduodenectomy. Pathological examination revealed mucinous adenocarcinoma with submucosal and subserosal invasion of the duodenum. We finally diagnosed this case as ampullary carcinoma.

CONCLUSIONS: The possibility of malignancy should be considered even in cases of duodenal obstruction that have not been diagnosed as malignant after repeated close examination.

INTRODUCTION: Primary pulmonary meningioma (PPM) is an exceptionally rare form of ectopic meningioma, with few cases documented in the literature, and even fewer reports of recurrence following surgical resection.

CASE PRESENTATION: This case study details a 69-year-old male patient diagnosed with PPM postoperatively, who experienced a recurrence 10 years after the initial surgery, necessitating a second surgical intervention. The postoperative pathological diagnoses from both surgeries confirmed transitional type primary pulmonary meningioma. The Ki-67 index from the first surgery was less than 1%, while the second postoperative pathology demonstrated a Ki-67 index of 5%.

CONCLUSION: The case emphasizes that, despite its benign classification, PPM has a potential for recurrence, underscoring the importance of ongoing, long-term follow-up in post-surgical management.

INTRODUCTION: Lymph node metastases after hepatocellular carcinoma (HCC) resection exist, although they are not common. However, solitary metastasis to the splenic artery lymph node with suspected pancreatic invasion after HCC resection is rare. In certain cases, surgical resection is performed to improve patient outcomes. We report a case of lymph node metastasis resected by laparoscopic distal pancreatectomy (LDP) in a patient with a unique anatomical anomaly known as portal annular pancreas (PAP).

CASE PRESENTATION: A 79-year-old Japanese man underwent laparoscopic left lateral segmentectomy for HCC. Two months after the surgery, alpha-fetoprotein levels remained elevated. Plain computed tomography revealed a swollen lymph node along the splenic artery involving the pancreas and the PAP. We suspected a solitary metastasis to the lymph node around splenic artery with pancreatic invasion. LDP was performed for complete resection of lymph node metastasis. Although the patient developed a grade B postoperative pancreatic fistula, he was discharged on postoperative day 33 under conservative treatment of antibiotics. He has remained recurrence-free for 4 years and 3 months after surgery.

CONCLUSIONS: LDP was successfully performed for lymph node metastasis around the splenic artery in an HCC patient and resulted in long-term survival. Surgeons should be aware of the unique anatomical characteristics of PAP during LDP.

INTRODUCTION: Ischemic colitis secondary to decompression sickness (DCS) is rare. Here, we present a case of ischemic colitis resulting in bowel necrosis following DCS.

CASE PRESENTATION: A 63-year-old male, with a history of hyperbaric oxygen (HBO) therapy for DCS 6 years ago, presented with limb and lower abdominal pain after a 55-m dive. The patient was diagnosed with DCS, and HBO therapy was initiated. However, due to worsening lower abdominal pain, contrast-enhanced computed tomography was performed on the second day. Imaging revealed a poorly enhanced segment extending from the rectum to sigmoid colon suggestive of bowel necrosis. Emergency surgery was performed, and the necrotic bowel segments were resected, followed by a descending colostomy. Pathological examination revealed ischemic colitis.

CONCLUSIONS: Ischemic colitis should be considered a differential diagnosis in patients with DCS presenting with abdominal symptoms. Surgical intervention may be required in patients with recurrent DCS, depending on the patient’s condition.

INTRODUCTION: Primary pulmonary myxoid sarcoma (PPMS) is a very rare low-grade sarcoma. It is known to have a characteristic chromosomal translocation at t(2;22)(q33;q12) and a distinctive genetic alteration, Ewing sarcoma breakpoint region 1 (EWSR1):cAMP response element binding protein 1 fusion. Most cases of PPMS reported so far have been found in the bronchi or bronchioles, and there are only a few cases of them arising from the peripheral lung parenchyma.

CASE PRESENTATION: A 58-year-old man was referred to our department for diagnosis and treatment because a computed tomography (CT) scan showed a 15 mm nodule in the left lung. For diagnosis and treatment, he underwent a video-assisted wedge resection. The tumor protruded from the lung parenchyma and had a very striking appearance. Histological features and immunostaining results were not enough to make the diagnosis. Fluorescence in situ hybridization (FISH) analysis was subsequently performed, which suggested EWSR1 gene rearrangement, leading to the final diagnosis of PPMS. The patient is alive 18 months postoperatively with no evidence of recurrence.

CONCLUSIONS: We encountered a rare case of PPMS arising from the peripheral lung parenchyma. In addition, our case was diagnosed as an overlap lesion of PPMS and angiomatoid fibrous histiocytoma. We can expect a good prognosis with surgical resection alone for the treatment of PPMS, but more accumulation of cases is desired for the establishment of an accurate diagnosis and prediction of the disease course.

INTRODUCTION: Perioperative mortality is significantly higher in cases of heart failure with severe left ventricular ejection fraction (LVEF) reduction, making it challenging to decide whether to proceed with surgery for early-stage breast cancer, which is not immediately fatal. However, the prognosis of heart failure has improved and breast cancer is increasingly becoming a prognostic factor. Herein, we report the case of a breast cancer patient with severe heart failure due to dilated cardiomyopathy (DC), who was deemed fit to undergo surgery under general anesthesia after obtaining sufficient informed consent and achieving improvement in heart failure symptoms during endocrine therapy.

CASE PRESENTATION: A 64-year-old female with a history of DC and sustained ventricular tachycardia, who had received cardiac resynchronization therapy with defibrillator implantation, underwent breast cancer surgery. She had been repeatedly hospitalized for heart failure with an LVEF of 19% and New York Heart Association (NYHA) Class III status, and heart transplant surgery was considered. However, a screening computed tomography scan revealed right breast cancer, and neither heart transplantation nor breast cancer surgery was performed. Endocrine therapy was initiated and failed 48 months after administration. Although the LVEF remained low at 21%, the NYHA classification improved to Class II, and she had not been hospitalized for heart failure for an extended period since her breast cancer diagnosis. Therefore, breast cancer surgery was performed under general anesthesia and no postoperative complications were observed throughout the course of the surgery.

CONCLUSION: Given that the prognosis for heart failure may statistically be better than that for breast cancer, early breast cancer surgery should be performed in patients with stable heart failure symptoms.

INTRODUCTION: Gastric adenocarcinoma with enteroblastic differentiation (GAED) is a rare subtype of gastric cancer known for its aggressive nature compared to conventional gastric adenocarcinoma. Due to its rarity and high malignancy, reports of successful medication therapy for Stage IV GAED are scarce. In this case, we report a GAED patient with peritoneal dissemination who responded well to combination chemotherapy with nivolumab, leading to the possibility of conversion surgery.

CASE PRESENTATION: A 74-year-old man presented with anemia and was diagnosed with GAED involving pancreatic infiltration and peritoneal dissemination. As first-line treatment, he underwent 9 cycles of S-1 and oxaliplatin chemotherapy combined with nivolumab. The tumor showed remarkable shrinkage. Staging laparoscopy revealed the disappearance of peritoneal nodules, and negative peritoneal cytology was confirmed intraoperatively. Consequently, conversion surgery was performed, involving laparoscopic distal gastrectomy with D2 lymph node dissection and Roux-en-Y reconstruction. Pathological examination showed ypT2N0M0, ypStage IB, with a chemotherapy response graded at 2a. Although peritoneal dissemination recurred 4 months after surgery, restarting nivolumab monotherapy significantly reduced ascites, and the patient maintained a partial response.

CONCLUSIONS: Stage IV GAED is associated with a poor prognosis; however, the advent of immune checkpoint inhibitors has expanded treatment options for these patients. In this case, we propose a personalized treatment strategy for GAED with peritoneal metastases that may improve clinical outcomes.

INTRODUCTION: In recent years, new molecularly defined tumor groups have been reported among tumors previously considered unclassifiable. Among them, gene fusions involving the CREB family of transcription factors, including cAMP-responsive element modulator (CREM), with genes encoding FET family RNA-binding proteins, such as Ewing sarcoma breakpoint region 1 (EWSR1), have recently been shown to be implicated in driving the pathogenesis of various tumor types. Here, we report our experience with a gastric mesenchymal tumor with epithelioid histology and an EWSR1::CREM fusion, which is rare but requires caution.

CASE PRESENTATION: A 58-year-old man with epigastric pain underwent esophagogastroduodenoscopy, which revealed a submucosal tumor, 40 × 30 mm in size, at the greater curvature of the upper gastric body. Surgical resection was scheduled because of easy bleeding from the tumor and because biopsy could not establish a diagnosis. The tumor was clinically considered benign because there was no significant accumulation on positron emission tomography scans. Therefore, we performed a local resection of the stomach. Histologically, the tumor consisted of a proliferation of keratin-positive, relatively uniform epithelioid cells arranged in sheets, with a scattering of lymphoid follicles in the surrounding area. Based on a pathology consultation, the tumor was diagnosed as a mesenchymal tumor with EWSR1::CREM fusion.

CONCLUSION: We experienced a gastric epithelioid mesenchymal tumor with EWSR1::CREM fusion genes. Since a malignant course has been reported in similar tumors in the stomach and abdominal cavity, such patients require careful follow-up.

INTRODUCTION: Congenital esophageal stenosis (CES) is a rare clinical condition found in 1 in 25000–50000 live births. Surgical treatment is required when endoscopic balloon dilatation is ineffective. Laparoscopic and thoracoscopic approaches are selected based on lesion location. Gastroesophageal reflux (GER) is often observed as a postoperative complication that necessitates additional fundoplication. We report a case of CES in the lower third of the esophagus that was treated with simultaneous thoracoscopic resection and Thal fundoplication using the right thoracic approach.

CASE PRESENTATION: The patient was a 6-month-old boy who presented with vomiting after consuming solid food. Although he had been previously treated by a physician, he was referred to our hospital for further examination because of persistent symptoms at 1 year and 7 months of age. As his oral intake was insufficient, he was thin compared with his twin brother. On esophagography, an abruptly narrowing lesion was found at the Th9-10 level, and congenital esophageal stenosis was diagnosed. Since balloon dilatation under upper gastrointestinal endoscopy was ineffective, the patient was treated surgically. Thoracoscopic esophagectomy (end-to-end anastomosis) and fundoplication (Thal procedure) were simultaneously performed via the right thoracic cavity. Although transient postoperative gastric paresis due to vagus nerve injury was observed, the patient improved with medical treatment and was discharged on postoperative day 14. He is currently able to ingest solid food orally, without GER.

CONCLUSIONS: CES can be a surgical indication for a thoracoscopic approach, depending on the site of the lesion. This is the first case in which anti-reflux surgery was performed simultaneously with thoracoscopic CES repair. We consider that this technique is useful for preventing not only GER, but also anastomotic leakage.

INTRODUCTION: While simultaneous complex surgical procedures such as right hemicolectomies with pancreaticoduodenectomies (RHPD) may increase overall surgical complexity, complications, and risk of death, it is the only cure for advanced ascending colon cancer (AACC) that has directly invaded the duodenum/pancreas. There are a few reports, especially from Japan. Here, we report an extremely rare case of a patient who underwent RHPD for AACC with direct invasion to the duodenum and liver and describe the patient’s long-term survival after en bloc resection.

CASE PRESENTATION: The patient was a 76-year-old man who presented with a chief complaint of right abdominal pain and weight loss of 12 kg over the past month. Colonoscopy revealed the entire circumference of a type 2 tumor in the ascending colon. Preoperative computed tomography showed a 12 cm mass lesion with wall thickening in the ascending colon which was also invading the second portion of the duodenum. MSI-H/dMMR was negative. RHPD and partial hepatectomy were performed with open surgery because of a preoperative diagnosis of clinical T4b (duodenum and liver) N1bM0 stage IIIc cancer. Although grade 2 adverse effects, which delayed gastric emptying was observed during the patient’s postoperative course, the patient’s condition resolved through conservative therapy. Oral intake started on postoperative day 17, and the patient was discharged on postoperative day 25. Capecitabine plus oxaliplatin was administered as adjuvant chemotherapy for 6 months. Hematoxylin and eosin staining revealed moderately differentiated adenocarcinoma invading the duodenum and liver. The patient was diagnosed as pathological T4b (duodenum and liver) N1bM0 stage IIIc cancer. No recurrence was noted up to 40 months after the surgery.

CONCLUSIONS: The only curative therapy for AACC with involvement of the duodenum is en bloc RHPD. Here, we described a case in which long-term survival was achieved by ensuring R0 with en bloc resection.