A stent-graft technique was developed by Parodi et al. and has been used clinically for thoracic endovascular aortic repair (TEVAR) since the 1990s. We evaluated how the new stent-graft technology contributed to expanding aortic surgery and improving surgical outcomes of aortic surgery. TEVAR was performed in a limited number of institutes in the early 2000s and was greatly enhanced by the approval of commercially available stent grafts in 2008. Its performance increased steadily thereafter, with 0 cases performed in 1999, 1658 in 2009, and 6461 in 2019. The ratio of TEVAR was 0% in 1999, which increased to 13.9% in 2009 and 28.5% in 2019, respectively. TEVAR has greatly contributed to the improvement of surgical outcomes, especially in non-dissection ruptured aneurysms and type B acute aortic dissection. TEVAR was performed in 53% of ruptured aneurysms, and the 30-day mortality rate improved to 13.9% in 2019 due to a 30-day mortality rate of 12.5% in TEVAR. The effect of TEVAR was more remarkable in patients with acute type B aortic dissection, where the 30-day mortality rate was 5.7%, and the procedure was performed in 75% of cases. The overall 30-day mortality rate improved to 7.0% for all patients with type B acute aortic dissection in 2019. The expansion of TEVAR using stent grafts greatly increased the number of aortic surgeries and played a significant role in improving surgical outcomes. Stent-graft technology has influenced the field of aortic surgery.

INTRODUCTION: Neoadjuvant gemcitabine plus S-1 (GS) therapy for resectable pancreatic cancer has been shown to prolong overall survival significantly compared with upfront surgery. Herein, we report two opposite cases of patients with resectable pancreatic cancer who underwent distal pancreatectomy after neoadjuvant GS therapy.

CASE PRESENTATION: In Case 1, a 49-year-old female with a 12 mm tumor in the pancreatic body (cT1N0M0, cStage IA, union for international cancer control [UICC] 8th edition) underwent two courses of neoadjuvant GS therapy followed by an open distal pancreatectomy. Pathological examination revealed no residual cancer and the patient was diagnosed with a pathological complete response (pCR) without recurrence 31 months after surgery. However, in Case 2, a 74-year-old male with a 12 mm tumor in the pancreatic body (cT1N0M0, cStage IA, UICC 8th edition) also underwent two courses of neoadjuvant GS therapy, and then a laparoscopic distal pancreatectomy was performed. Pathological examination showed invasive pancreatic ductal adenocarcinoma with a 20 mm tumor. The tumor exhibited invasion into the lumen of the splenic vein and retroperitoneal tissue (ypT1N0M0, ypStage IA, UICC 8th edition). Adjuvant chemotherapy with S-1 was started, but 4 months postoperatively, a significant rise in serum CA19-9 levels was observed with multiple hepatic metastases and portal venous tumor thrombus. Gemcitabine plus nab-paclitaxel (GnP) therapy was started, however, the tumor progressed rapidly. The patient died 6 months after surgery.

CONCLUSIONS: Neoadjuvant GS therapy is potentially expected to have a significant therapeutic effect as the pCR. Nevertheless, even after surgical resection, some patients still exhibit extremely poor prognosis. Therefore, it is necessary to clarify their clinical characteristics.

INTRODUCTION: Esophageal carcinosarcoma is a rare malignant neoplasm composed of both carcinoma and sarcoma components. Here, we report a case of esophageal carcinosarcoma in a patient with cancers of the transverse colon and stomach who underwent simultaneous resection of all 3 malignancies.

CASE PRESENTATION: A 71-year-old man presented with dysphagia and was diagnosed with carcinoma in the mid-thoracic esophagus. Laboratory data showed normal tumor markers—carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC), and carbohydrate antigen 19-9 (CA19-9). Esophagoscopy confirmed the presence of a polypoid tumor in the middle thoracic esophagus. Endoscopic biopsy specimens were reported as spindle cell carcinoma. Colonoscopy revealed a semicircular tumor in the transverse colon. Simultaneous esophagectomy and regional lymphadenectomy and transverse colon resection using video-assisted thoracoscopic surgery (VATS) and hand-assisted laparoscopic surgery (HALS) were planned. Intraoperative findings revealed advanced cancer in the upper part of the stomach, which was also resected. Macroscopically, there was an 11-cm type 1 tumor in the middle thoracic esophagus and a 3.5-cm type 3 tumor in the gastric cardia. Microscopically, the esophageal tumor was composed of well-differentiated squamous cell carcinoma and spindle-shaped cells resembling leiomyosarcoma and was diagnosed as carcinosarcoma. Spindle-shaped sarcomatous cells were positive for vimentin and α-smooth muscle actin (αSMA) by immunohistochemistry. Most of the tumor showed highly atypical sarcomatous component that reached deep into the submucosa, and regional lymph node metastases were observed. Gastric cancer was a moderately differentiated tubular adenocarcinoma that penetrated the serosa and reached the peritoneal cavity. The transverse colon tumor was a well-differentiated adenocarcinoma invading the muscularis mucosa.

CONCLUSIONS: We report a rare case of triple cancer, including esophageal carcinosarcoma. Simultaneous resection of esophageal carcinosarcoma with multiple cancers should be carefully considered based on the patient’s condition and reconstruction method.

INTRODUCTION: Solitary fibrous tumor (SFT) is a mesenchymal tumor and accounts for less than 2% of all soft tissue tumors. It is most commonly found in the pleura and has a relatively good prognosis.

CASE PRESENTATION: A 53-year-old woman was diagnosed with thyroid cancer and underwent a plain CT scan for preoperative examination. A mass measuring 23 mm in maximum diameter was incidentally found near the greater curvature of the stomach. Although its continuity with the stomach was unclear, an additional 18F-fluorodeoxyglucose positron emission tomography (FDG-PET)/CT scan revealed abnormal accumulation of Sstandardized uptake value (SUV) of max 4.2 at the same site. Percutaneous biopsy and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) were anatomically difficult, so a laparoscopic resection was performed as a diagnostic treatment. The specimen measured 28 mm in maximum diameter and was elastically hard. There was a proliferation of small- to medium-sized spindle cells, and no atypical cells were observed. No tumor components were found at the resection margin. The diagnosis of SFT was therefore made. The patient was discharged 2 days after surgery. Although it would have been difficult to diagnose the tumor based on preoperative imaging alone, we were able to perform minimally invasive tumor removal by laparoscopic surgery and make a diagnosis.

CONCLUSIONS: Although the prognosis of SFT is generally good, its treatment has not been established. In particular, SFT originating from the greater omentum is extremely rare. We report this case along with some relevant literature.

INTRODUCTION: Myoepithelioma-like tumor of the vulvar region (MELTVR) is a mesenchymal neoplasm first reported in 2015 and typically develops from the inguinal to the vulvar regions of adult women.

CASE PRESENTATION: Here we report the case of a 42-year-old woman who presented with right inguinal tumor. The tumor had recently increased in size continuously. Computed tomography (CT) showed a homogeneous neoplastic lesion along the uterine cord in the right inguinal region and marginal resection was performed. Pathological examination revealed a well-defined tumor. And there were areas of epithelial-like tumor cells arranged in a reticular or cord-like pattern against a background of mucinous stroma, and areas of spindle-shaped cells growing in mucinous substrate with transition from epithelial cells. The nucleus was irregular in size and shape. Necrotic nests were scattered in the tumor. Immunohistological examination showed that the tumor cells were positive for epithelial membrane antigen (EMA), estrogen receptor (ER), and progesterone receptor (PgR). Alpha-smooth muscle actin (α-SMA) was slightly positive. The tumor was negative for cytokeratin AE1/AE3, p63, desmin, CD34, S100, glial fibrillary acidic protein (GFAP), and SOX10. Loss of INI1 protein expression was also confirmed. The patient was suspected of having high-grade myoepithelioma on pathological diagnosis at our hospital. However, immunohistological findings led to the diagnosis of MELTVR. The patient underwent additional wide excision and has been alive 10 months postoperatively without recurrence.

CONCLUSIONS: Due to its rarity, it is difficult to make preoperative diagnosis of MELTVR. Awareness of this condition can contribute to accurate diagnosis and appropriate management in adult female patients presenting with swelling extending from the inguinal to the vulvar regions.

INTRODUCTION: Tamoxifen (TAM) is a well-established treatment for hormone receptor-positive breast cancer with a known side-effect profile that includes hot flashes, genital bleeding, and diarrhea (0.1%–5%). Other notable side effects include liver damage, abnormal vaginal discharge, depression, dizziness, and headaches of unknown frequency. However, blood cell count reduction has not yet been reported as a side effect in Japan.

CASE PRESENTATION: A 46-year-old female patient was diagnosed with right breast cancer (cT1N0M0). The patient underwent partial right breast resection and sentinel lymph node biopsy. Owing to the positive surgical resection margin, a mastectomy was performed. Pathological analysis of the surgical specimen confirmed invasive ductal carcinoma (estrogen receptor [ER]: 95%, progesterone receptor [PgR]: 85%, HER2: 2+ [fluorescence in situ hybridization, FISH negative]), with macrometastasis in one sentinel lymph node. Postoperative treatment included chemotherapy (dose-dense adriamycin and cyclophosphamide [AC] to dose-dense paclitaxel [PTX]), irradiation, and TAM. While initial blood test results before starting TAM showed mild anemia (Hb: 8.9 g/dL Grade 2), a follow-up blood test 5 months after initiating TAM revealed a significant decrease in blood cell counts (white blood cell [WBC]: 2600/μL Grade 2, neutrophil [neu]: 0.55 × 10³/μL Grade 3, Hb: 7.7 g/dL Grade 2, platelet [PLT]: 13.3 × 10⁴/μL). Considering the onset of symptoms following TAM administration, drug-induced pancytopenia was suspected. TAM and its concomitant medication pregabalin were discontinued. However, the blood cell counts continued to decline, necessitating further investigation. Myelodysplastic syndrome (MDS) was suspected, leading to multiple bone marrow biopsies. However, no definitive hematological disorder was diagnosed. The patient received transfusions and granulocyte colony-stimulating factor (G-CSF) injections based on the blood cell count. Approximately 4 months after the onset of neutropenia, gradual recovery was observed and spontaneous remission occurred. Given the rarity of spontaneous recovery from MDS, TAM is considered a potential causative agent of the observed decline in blood cell counts.

CONCLUSIONS: We report a case of suspected drug-induced cytopenia associated with tamoxifen administration.

INTRODUCTION: Von Willebrand disease (VWD) is the second most common inherited coagulation disorder, and appropriate perioperative management is necessary when considering major surgery. There are few reports of patients with VWD who have undergone hepatectomy, especially minimally invasive hepatectomy. To our knowledge, this is the first reported case of a patient with VWD who successfully underwent robotic hepatectomy with von Willebrand factor (VWF) and factor VIII (FVIII) supplementation.

CASE PRESENTATION: A 75-year-old female was referred to our hospital because of a liver tumor that was diagnosed during follow-up after hepatitis C treatment. She had also been diagnosed with VWD in her 30s. CT and MRI showed a 24-mm mass in segment 8 of the liver, bordered by the middle hepatic vein (MHV). To ensure safe perioperative management, replacement therapy with a VWF- or FVIII-containing concentrate was administered from preoperative day 1 to POD 14. Robotic extended segmentectomy (segment 8) was performed, with resection of the MHV. Liver parenchyma was dissected using the crush and clamp technique under the Pringle maneuver. Estimated intraoperative blood loss was 160 mL, and total operative time was 601 min. The patient needed 2 units of fresh frozen plasma on POD 1; however, no other transfusions, including red blood cells, were required. Although the patient presented with postoperative ascites and was treated with diuretics, she was discharged on POD 20 without any bleeding event. The final pathological finding was intrahepatic cholangiocarcinoma.

CONCLUSIONS: We encountered a patient with intrahepatic cholangiocarcinoma and VWD who was successfully treated with anatomical hepatectomy by robotic-assisted laparoscopic surgery under perioperative replacement therapy with a VWF- or FVIII-containing concentrate. With appropriate perioperative management, major hepatectomy can be applied for VWD patients despite their high risk of postoperative hemorrhagic complications.

INTRODUCTION: Thromboangiitis obliterans (TAO) has become increasingly uncommon in Japan due to declining smoking prevalence. However, in advanced cases with severely compromised distal vasculature, achieving durable limb salvage remains a formidable surgical challenge.

CASE PRESENTATION: A 51-year-old man with a 12-year history of TAO presented with rest pain and a necrotic ulcer on the 2nd toe. He had recently ceased smoking after a 31-year history. Imaging demonstrated complete occlusion of the popliteal and tibial arteries, with foot perfusion reliant on corkscrew collaterals. The ankle-brachial index was 0.43, and skin perfusion pressure (SPP) was critically low. A severely diseased plantar artery was identified as a potential distal target. Given the high risk of graft failure, a hybrid strategy combining in situ bypass and surgical distal venous arterialization (DVA) was preoperatively planned. To mitigate perioperative vasospasm, a lumbar sympathetic block was administered 1 week prior to surgery. An in situ bypass using the ipsilateral great saphenous vein was constructed from the superficial femoral artery to the plantar artery. DVA was established via retrograde puncture of the plantar vein, balloon angioplasty for valve sites, and end-to-side anastomosis to the bypass graft. Early duplex ultrasonography revealed anastomotic stenosis at the DVA site as well as stenosis at valve sites, both of which were successfully managed with a single endovascular procedure. The toe stump healed completely within 3 months. The graft remained patent for 2 years, and SPP was preserved even after graft occlusion. Notably, graft failure coincided with DVA occlusion, suggesting its critical role in maintaining flow. At 42 months postoperatively, the patient remained ulcer-free with favorable perfusion, pain-free ambulation, and full return to work.

CONCLUSIONS: Preoperatively planned surgical DVA, in conjunction with sympathetic modulation and timely postoperative intervention, may offer a durable limb salvage strategy in advanced TAO with limited distal targets.

INTRODUCTION: Undifferentiated embryonal sarcoma (UES) of the liver (UESL) is a tumor that is rare in adults. UESL is composed of undifferentiated mesenchymal tumor cells, with characteristic normal bile duct cells found at the tumor periphery. We present a rare case of UESL containing an adenocarcinoma component in one part of the tumor.

CASE PRESENTATION: A 68-year-old male had a tumor with an 8-cm diameter in the left lateral liver segment. CT showed a cystic tumor with a solid component and a heterogeneous area. In the solid component, the contrast effect was weak in the arterial phase and uniform in the late phase. Imaging suggested that the internal tumor area was necrotic or hemorrhagic. We diagnosed it as hemorrhagic hepatocellular carcinoma or combined hepatocellular–cholangiocellular carcinoma. The patient exhibited normal liver function. Left lateral segmentectomy was performed. Macroscopically, the tumor was cystic, with hemorrhagic/necrotic deposits and a solid portion composed of tumor cells. Histopathologically, the tumor had 2 components. One was a nonepithelial tumor comprising immature spindle-shaped and stellate plaques, with positivity for the mesenchymal markers vimentin and CD68 and negativity for myogenic, neurogenic, and other markers. This component was diagnosed as UES. The other component comprised epithelial and adenocarcinoma tissues with differentiated bile duct cells. The tumor was mainly composed of UES cells, with the adenocarcinoma component located predominantly in the periphery.

CONCLUSIONS: We present a unique case of UESL containing UES cells and adenocarcinoma cells at the periphery. A combination of UESL and adenocarcinoma is extremely rare, even among hepatic carcinosarcomas.

INTRODUCTION: Esophageal retention cysts are rare, benign lesions that can mimic submucosal tumors. Their clinical presentation and imaging characteristics may lead to diagnostic challenges, particularly when fluorodeoxyglucose-positron emission tomography/CT (FDG-PET/CT) shows increased uptake, raising suspicion of malignancy.

CASE PRESENTATION: A 77-year-old man presented with epigastric pain. Upper gastrointestinal endoscopy revealed an esophageal mass, prompting referral to our hospital. Endoscopic ultrasonography (EUS) identified a hypoechoic submucosal tumor with multiple cystic components in the lower esophagus. However, EUS-guided fine-needle aspiration (EUS-FNA) did not yield a definitive diagnosis. CT scan demonstrated a 60-mm space-occupying lesion (SOL) in the lower thoracic esophagus with peripheral contrast enhancement and a central low-density area. MRI revealed a SOL in the lower esophagus with high signal intensity on T2-weighted images and moderate signal intensity on T1-weighted images. The lesion contained cystic components exhibiting high T2 and low T1 signal intensities. FDG-PET/CT revealed intense FDG uptake, increasing from maximum standardized uptake value (SUVmax) 11 to 18 over time. Given the large size of the tumor, symptomatology, and inability to exclude malignancy—particularly high-risk gastrointestinal stromal tumor—surgical resection was performed. Laparoscopic esophagectomy was conducted using intraoperative endoscopy for tumor identification. The esophagus was transected proximally using a linear stapler, followed by extracorporeal gastric conduit reconstruction and the overlap technique was used to perform an esophagogastric anastomosis. Postoperatively, anastomotic leakage was detected on day 3, requiring emergency reoperation. The leak had resolved by POD 26, and the patient was discharged on day 48 after the second surgery (day 51 after the initial surgery). Histopathological examination revealed multiple cysts of varying sizes within the lamina propria, lined by columnar epithelium, with no evidence of malignancy. The final diagnosis was esophageal retention cyst.

CONCLUSIONS: This case highlights the diagnostic challenge of esophageal retention cysts with high FDG uptake. While PET/CT is essential in oncologic imaging, FDG accumulation does not always indicate malignancy.

INTRODUCTION: Immunoglobulin G4-related disease (IgG4-RD) rarely involves the esophagus, typically causing stenosis that presents significant diagnostic and therapeutic challenges. Due to its rarity and its mimicry of other conditions, obtaining a definitive preoperative diagnosis can be difficult. This report details a case of IgG4-RD-induced esophageal stenosis with initial diagnostic ambiguity, which was successfully managed with mediastinoscopy-assisted esophagectomy (MAE), highlighting this minimally invasive approach in a patient with comorbidities.

CASE PRESENTATION: A 70-year-old male with comorbidities, including obstructive pulmonary disorder, presented with progressive dysphagia and epigastric discomfort. Endoscopy revealed a persistent mid-esophageal ulcer and a non-passable circumferential stricture; multiple biopsies were nondiagnostic for malignancy or infection. Given the refractory nature of the stenosis, MAE with gastric conduit reconstruction was performed. The postoperative course was uneventful, and the patient achieved symptom resolution without medication. Histopathological examination of the resected esophagus confirmed IgG4-RD, showing obliterative phlebitis and a dense infiltrate of IgG4-positive plasma cells (80/high-power field; IgG4/IgG ratio 80/85).

CONCLUSIONS: This case underscores that IgG4-RD should be considered in the differential diagnosis of refractory esophageal stenosis, even with initially inconclusive biopsies. While serum IgG4 measurement has low sensitivity, it is still recommended. For benign esophageal stenosis of unclear etiology, particularly in patients with significant comorbidities, MAE can be a useful and potentially curative surgical option, offering symptom resolution and the possibility of a drug-free outcome.

INTRODUCTION: Intra-aortic balloon pumping (IABP), Impella, and veno-arterial extracorporeal membrane oxygenation (VA-ECMO) are common percutaneous devices used to manage hemodynamic instability in patients with cardiogenic shock. These devices play a critical role in providing circulatory support. However, they may fail to achieve sufficient left ventricular unloading in patients with aortic valve regurgitation (AR), potentially complicating treatment strategies. In such challenging cases, an extracorporeal left ventricular assist device (LVAD) may serve as an effective alternative solution.

CASE PRESENTATION: A 61-year-old man presented with heart failure and cardiogenic shock, further complicated by AR. Despite intensive inotropic therapy, his condition deteriorated, leading to significant hepatic and renal dysfunction. Echocardiography revealed left ventricular dysfunction with an ejection fraction of 23.5%, as well as moderate aortic, mitral, and tricuspid valve regurgitation. Initial management with VA-ECMO proved inadequate, necessitating the implantation of an extracorporeal LVAD. This intervention resulted in marked improvements in hemodynamics and multi-organ function. Subsequently, the patient underwent successful surgical procedures, including aortic valve replacement, mitral and tricuspid annuloplasty, and pulmonary vein isolation. He was discharged on day 51.

CONCLUSIONS: This case highlights the challenges in managing cardiogenic shock with AR, where conventional devices like IABP, Impella, and VA-ECMO may exacerbate the condition. The use of an extracorporeal LVAD provided effective left ventricular unloading, enabling successful preoperative optimization and surgery. This case supports the utility of LVAD as a bridge to surgery in patients with cardiogenic shock and AR, suggesting a need for further research into optimal management strategies in such complex cases.

INTRODUCTION: Parastomal hernias with loss of domain are those in which it is difficult to return the hernia contents to the abdominal cavity and close the hernia orifice using standard mesh repair methods. We encountered a case in which abdominal wall closure was achieved safely by reducing the hernia content through bowel resection.

CASE PRESENTATION: The patient, a 50-year-old man, had a history of ulcerative colitis with a complex anal fistula, resulting in construction of a stoma with double orifices using the sigmoid colon. He presented requesting surgery because his parastomal hernia had increased greatly in size, and stoma management became difficult. Abdominal CT showed a large hernia with an incisional hernia volume to peritoneal volume ratio >80%. Total colectomy was performed, and a stoma was reconstructed at another site. The hernia orifice was closed using a fascia lata graft. No postoperative abdominal compartment syndrome was observed. Six months later, abdominal CT showed a small hernia of the abdominal wall; however, the stoma was easily managed, and the patient’s quality of life improved.

CONCLUSIONS: Bowel resection for volume reduction may be an effective option for the repair of incisional hernias with loss of domain.

INTRODUCTION: Primary sternal osteomyelitis (PSO) is a rare disease that occurs without any contiguous focus of infection, and there are few reports of acute mediastinitis due to PSO. In this report, we describe a case of PSO with acute mediastinitis successfully treated with a minimally invasive approach.

CASE PRESENTATION: A 71-year-old man visited his local doctor for anterior chest pain. He had no history of trauma or chest surgery. He was treated conservatively because of a few abnormalities on CT. However, his symptoms worsened, and a CT was re-taken 13 days later. The CT showed an abscess on the left side of the anterior mediastinum and subcutaneous tissues, as well as destruction of the sternum. With the diagnosis of acute mediastinitis and mediastinal abscess, thoracoscopic and subcutaneous drainages of the abscess were performed. After surgery, blood culture examination showed methicillin-sensitive Staphylococcus aureus, and we judged the mediastinitis to be caused by PSO. The thoracic drain was removed on postoperative day 39, the open subcutaneous wound closed spontaneously, and the patient was discharged on postoperative day 45. He continued oral antibiotics for the next 2 months, and the abscess cavity completely resolved.

CONCLUSIONS: Although PSO is rare, it can lead to mediastinitis and should be suspected when anterior chest pain is present. Our case of PSO with acute mediastinitis progressed rapidly over a few days but could be treated with minimally invasive thoracoscopic and subcutaneous drainages, without the need for invasive sternal debridement and drainage.

INTRODUCTION: Nasojejunal tube placement is a rare cause of small bowel intussusception. It is usually treated with tube removal, but a few cases require surgical reduction. We report a case of small bowel intussusception due to a nasojejunal tube shortly after surgery for ileal atresia, in which surgical reduction was required despite removal of the tube.

CASE PRESENTATION: A female infant underwent intestinal anastomosis for type III-A ileal atresia on the day of birth. A nasojejunal tube was placed for abdominal decompression until the temporary anastomotic passage obstruction improved. Bowel dilatation was successfully resolved; however, bilious gastric residuals suddenly increased again on postoperative day (POD) 11. Sonography revealed small bowel intussusception around the nasojejunal tube. As spontaneous reduction did not occur after tube removal, surgical reduction using the Hutchinson technique was performed on POD 20, including the release of adhesions between the intussusceptum and intussuscipiens of the jejunal intussusception. The patient experienced an uneventful course after surgical reduction.

CONCLUSIONS: Sonography should be performed to screen for small bowel intussusception in patients presenting with bilious vomiting during nasojejunal tube placement. The prompt removal of the tube following a diagnosis of small bowel intussusception (SBI) is essential to prevent adverse events, such as adhesions between the intussuscepted bowel loops. If intussusception does not resolve shortly after tube removal, surgical intervention is indicated.

INTRODUCTION: Fish bone ingestion is common but rarely causes complications such as abdominal wall abscesses, which can mimic malignancies such as sarcomas on imaging. Abscesses require drainage and antibiotics, while sarcomas need wide excision. Therefore, the differentiation between abscesses and sarcomas is important and often requires multidisciplinary involvement.

CASE PRESENTATION: A 70-year-old woman presented with anorexia and a painful abdominal mass. Laboratory tests showed inflammation but normal tumor marker concentrations. The abdominal wall mass was hard and poorly mobile. Ultrasound showed a heterogeneous, mosaic-like internal structure, and CT and positron emission tomography-CT findings strongly suggested a malignant tumor such as sarcoma. We performed surgery and confirmed the presence of an abdominal wall abscess with small intestinal penetration caused by an ingested fish bone. The small intestine was partially resected, and pathology showed no malignancy. The patient recovered well and was discharged on postoperative day 9. The final diagnosis was an abdominal wall abscess caused by an ingested fish bone that perforated the small intestine.

CONCLUSIONS: We present a rare case of an abdominal wall abscess caused by penetration of the small intestine by an ingested fish bone.

INTRODUCTION: Colorectal cancer (CRC) can metastasize to various sites, including the liver, lungs, ovaries, adrenal glands, and lymph nodes. Approximately 1%–2% of patients with CRC develop para-aortic lymph node metastases. Herein, we report a case of surgical resection of an isolated, metachronous, retrocaval lymph node recurrence of rectal cancer above the renal vein.

CASE PRESENTATION: A 77-year-old woman was diagnosed with a solitary metachronous retrocaval lymph node metastasis from rectal cancer. The patient underwent robot-assisted laparoscopic abdominoperineal resection. The pathological status was T3, N0, M0, or Stage IIA. No recurrence was observed for 13 months after the initial surgery. CT revealed a 24-mm tumor on the dorsal side of the inferior vena cava (IVC). Tumor resection was performed, including right adrenalectomy, Spiegel lobectomy, and partial resection of the IVC. Pathological findings revealed adenocarcinoma metastasis to a solitary lymph node, which invaded the IVC and Spiegel lobe.

CONCLUSIONS: This is the first report of a surgical resection of a retrocaval lymph node metastasis from CRC that invaded both the IVC wall and the liver.

INTRODUCTION: Atezolizumab plus bevacizumab combination therapy (atezo-bev) has been widely used worldwide as the first-line treatment for unresectable hepatocellular carcinoma (HCC). Intratumoral hemorrhage has been reported as a rare adverse event of atezo-bev. However, no previous cases of HCC rupture during atezo-bev have been reported. Herein, we demonstrate a case of tumor rupture in a patient with recurrent HCC following atezo-bev, who was successfully managed with transcatheter arterial embolization (TAE).

CASE PRESENTATION: An 80-year-old man with multiple recurrent HCCs (at least 4 lesions with a maximum tumor diameter of 35 mm protruding from the liver surface) developed epigastralgia immediately after the first cycle of atezo-bev. CT revealed a ruptured HCC in the left lateral lobe. TAE was performed, and the patient continued to receive atezo-bev without any subsequent tumor bleeding.

CONCLUSIONS: Tumor rupture should be considered in patients with HCC following atezo-bev treatment.

INTRODUCTION: Incisional hernia is one of the postoperative complications after abdominal surgery including laparoscopic liver resection. There is often intractable ascites after liver resection, especially for patients with severe cirrhosis. In the present study, we report the case of ruptured incisional hernia due to the pressure from massive ascites, which was successfully repaired using an anterolateral thigh (ALT) flap.

CASE PRESENTATION: A 78-year-old man had hepatocellular carcinoma and underwent laparoscopic left lateral sectionectomy. There was no short-term postoperative complication during hospital stay and at discharge, but approximately 5 months postoperatively, massive ascites gradually accumulated that was intractable, and resistant to diuretic drugs. There was eventually rupture of incisional hernia at the umbilical port scar, caused by strong compression from this ascites. One year postoperatively, the umbilical skin was seen to be perforated and there was intestinal prolapse. Hernia repair using artificial prosthesis was at risk of infecting ascites and leading to peritonitis. In collaboration with plastic surgeons, we therefore planned incisional hernia repair using an ALT flap. There was severe adhesion between the hernia sac and the small intestine, therefore we had to find the edge of the defective rectus sheath with careful dissection. After resection of the hernia sac, the peritoneum could be closed by continuous suture. The ALT flap obtained by plastic surgeons was elevated through an inguinal subcutaneous tunnel, rotating around the preserved perforator of the lateral circumflex femoral artery. Then, we sutured the edge of the rectus sheath and the ALT skin flap. Operation time was 265 min and the amount of intraoperative bleeding was 15 mL. After the operation, the patient felt dramatic improvement of hernia symptoms and he was discharged on the 16th postoperative day without any complications. Ascites was resolved by use of diuretic drugs and cell-free and concentrated ascites reinfusion therapy.

CONCLUSIONS: Intractable ascites is often a problem in cirrhotic patients after liver resection and can become difficult to treat when complicated by abdominal wall incisional hernias. We successfully performed hernia repair using an ALT flap without the use of artificial materials for ruptured incisional hernia caused by intractable ascites.

INTRODUCTION: Inflammatory myofibroblastic tumors (IMTs) are rare mesenchymal neoplasms characterized by spindle cell proliferation and inflammatory infiltration, but with an unclear etiology. Although IMTs most commonly arise in the lungs, extrapulmonary cases have been documented at various anatomical sites. Approximately 50% of IMTs harbor anaplastic lymphoma kinase (ALK) rearrangements; however, the genetic landscape of ALK-negative cases remains largely unknown. We report a rapidly growing IMT in the right rectus abdominis muscle and present whole-exome sequencing (WES) findings that revealed novel genetic mutations beyond ALK rearrangements.

CASE PRESENTATION: A 38-year-old woman with no significant medical history presented with a rapidly enlarging mass in the right lower abdomen. Computed tomography showed a well-defined tumor on the dorsal side of the right rectus abdominis muscle exhibiting progressive enhancement. Fine-needle biopsy initially suggested the presence of proliferative fasciitis. Owing to rapid tumor growth from 40 to 61 mm within 3 months, laparoscopic surgical resection was performed, including a portion of the posterior sheath and rectus abdominis muscle. Pathological examination confirmed the presence of an IMT and revealed spindle cell proliferation, nuclear atypia, and inflammatory infiltration. Immunohistochemical analysis revealed positivity for smooth muscle actin (SMA) and ALK, partial positivity for desmin, and negativity for cluster of differentiation 34 (CD34) and cytokeratin, compatible with an IMT. WES identified 7 genetic mutations, none of which have been previously reported for IMT in the catalogue of somatic mutations in cancer (COSMIC) database, suggesting novel genetic associations.

CONCLUSIONS: This case highlights a rare and rapidly growing IMT in the rectus abdominis muscle and underscores the value of molecular analysis in understanding the pathogenesis of IMT. Identification of novel mutations through WES expands the genetic landscape of IMT and may provide insights into tumorigenesis and potential therapeutic targets. Further research is required to explore the clinical implications of these mutations in IMT progression and treatment.

INTRODUCTION: Portal vein (PV) and splenic vein (SV) stenosis are known complications of pancreatoduodenectomy (PD) and often lead to portal hypertension. PV stenosis extending to the SV confluence can result in sinistral portal hypertension (SPH), characterized by gastrointestinal varices and splenomegaly in the presence of normal liver function. There is no standardized treatment strategy for SPH following PD.

CASE PRESENTATION: A 42-year-old female underwent robot-assisted PD for a pancreatic neuroendocrine tumor without immediate PV complications. Postoperatively, the patient experienced fluid retention; however, this did not pose a problem, and no therapeutic intervention was necessary. Two months later, imaging revealed PV stenosis and SV obstruction. Eleven months after surgery, the patient presented with melena, and imaging confirmed the presence of gastroesophageal varices with severe PV stenosis and complete SV obstruction. Endoscopic variceal ligation was performed, and the hemodynamic status of the portal system was assessed using computed tomography during arterial portography (CTAP). CTAP showed communication between the superior mesenteric vein and the SV via the middle colic vein. Therefore, we decided to perform PV stenting. The stent was successfully placed, resulting in a significant improvement in the esophageal varices. The patient was discharged on postoperative day 4, receiving anticoagulant therapy, with no further complications.

CONCLUSIONS: This case demonstrates the efficacy of PV stenting after careful hemodynamic assessment in a patient who developed SPH due to PV stenosis and SV obstruction following PD.

INTRODUCTION: Omphalocele is a congenital abdominal wall defect that is characterized by herniation of the abdominal viscera through the umbilical ring. Compared with gastroschisis, omphalocele is less frequently associated with ileal atresia. This report describes a preterm newborn with a minor omphalocele complicated by ileal atresia, a complication that may have been previously underestimated.

CASE PRESENTATION: A 5-day-old preterm male infant (gestational age 34 weeks, birth weight 2005 g) presented with delayed meconium passage and persistent bilious gastric aspirates. Antenatal ultrasound revealed an umbilical cyst without any other anomalies. On day 4, a gastrointestinal series examination revealed dilated small bowel loops and a small-caliber colon. Surgical exploration revealed bowel contents entrapped within a 2.2-cm minor omphalocele. The infant was diagnosed with type IIIa distal ileal atresia and colonic atresia, and end-to-end anastomosis was performed. The patient was discharged at a corrected age of 6 weeks on a hypoallergenic semi-elemental formula (50 mL per meal) and partial parenteral nutrition. He was successfully weaned off parenteral nutrition by a corrected age of approximately 10 months. His weight gain was stable, although it remained at approximately the 3rd percentile, and no obvious neurodevelopmental complications were observed.

CONCLUSIONS: This case highlights the importance of recognizing that even minor omphaloceles can be associated with ileal atresia. In neonates with minor omphaloceles, symptoms of feeding intolerance should prompt consideration of this complication.

INTRODUCTION: Although pancreatic cancer rarely co-occurs with autoimmune pancreatitis (AIP), distinguishing between AIP relapse and pancreatic cancer remains difficult, potentially leading to delayed diagnosis. A recent nationwide survey in Japan indicated that pancreatic cancer underlies a significant proportion of cancer-related deaths among patients with AIP.

CASE PRESENTATION: Here, we present two cases of pancreatic cancer that initially mimicked AIP relapse. Case 1: An 89-year-old man with a long-standing history of pancreatic enlargement began steroid therapy for suspected AIP based on elevated serum IgG4 levels. Although IgG4 levels initially decreased following the treatment, they subsequently rose again, accompanied by worsening pancreatic swelling. Endoscopic ultrasound-fine-needle aspiration (EUS-FNA) revealed adenocarcinoma. Case 2: A 76-year-old woman with AIP, diagnosed based on focal pancreatic body enlargement and elevated IgG4, experienced multiple steroid-responsive relapses over 8 years. While tapering steroids, a new pancreatic nodule was detected on MRI, which was characterized by high signal intensity on diffusion-weighted imaging. Although the initial EUS-FNA was negative for carcinoma, a repeat biopsy 10 months later confirmed pancreatic cancer. Both patients underwent laparoscopic or robotic distal pancreatectomy with lymphadenectomy, and histopathological analysis confirmed pancreatic cancer arising in severely AIP-affected pancreatic tissue.

CONCLUSIONS: In patients showing clinical or radiological worsening during AIP follow-up, repetitive diagnostic evaluations are warranted to facilitate the timely detection of underlying pancreatic cancer.

INTRODUCTION: Transmesocolic hernia of the ascending colon is an extremely rare cause of small bowel obstruction. Due to its rarity and nonspecific clinical features, preoperative diagnosis of internal hernia is challenging.

CASE PRESENTATION: We report the case of a 95-year-old female patient (body mass index: 19.5) without a history of abdominal surgery, who presented with vomiting and abdominal pain. The patient had a medical history of cerebral infarction, pneumonectomy, hypertension, hyperlipidemia, and dementia. Laboratory test results revealed leukocytosis and mild inflammation. Abdominal CT revealed closed-loop ileus on the left side of the ascending colon with localized small bowel dilatation. Chest CT indicated aspiration pneumonia. Based on these findings, a preoperative diagnosis of an internal hernia with strangulated ileus and aspiration pneumonia was made, necessitating an emergency surgery. Intraoperatively, a segment of the jejunum located 50–70 cm from the ligament of Treitz was herniated through a congenital defect in the ascending mesocolon. The ischemic jejunal bowel was resected and the mesenteric defect was closed. The operative time was 81 min with minimal blood loss. The patient experienced no surgical complications and was discharged on postoperative day 50, following treatment for aspiration pneumonia.

CONCLUSIONS: Although transmesocolic hernias of the ascending colon are extremely rare, they should be considered in the differential diagnosis of small bowel obstruction, particularly in older, thin female patients without a history of abdominal surgery. Early diagnosis and timely surgical intervention are essential for achieving favorable outcomes.

INTRODUCTION: Segmental arterial mediolysis (SAM) is a rare, non-atherosclerotic, non-inflammatory arteriopathy characterized by lysis of the arterial media, leading to aneurysm formation and possible rupture. Although visceral arteries are typically involved, SAM-induced omental bleeding is extremely uncommon. While transcatheter arterial embolization (TAE) has been reported, surgical resection offers both definitive hemostasis and histopathological confirmation.

CASE PRESENTATION: A 56-year-old man presented with upper abdominal pain without a history of trauma. Contrast-enhanced CT revealed a hematoma and fusiform dilation of an omental artery, suggesting omental hemorrhage. As he was hemodynamically stable, initial conservative management was chosen. However, a follow-up CT on day 7 demonstrated aneurysm enlargement, prompting laparoscopic partial omentectomy. Intraoperative findings included a 5-cm hematoma in the central omentum. Histopathological examination showed vacuolization of the tunica media and loss of the internal elastic lamina, confirming the diagnosis of SAM. The patient had an uneventful postoperative course and was discharged on the 3rd postoperative day.

CONCLUSIONS: This rare case of SAM-related omental bleeding was successfully treated with laparoscopic partial omentectomy. Tailored treatment strategies including laparoscopic surgery are essential for optimal outcomes in SAM.

INTRODUCTION: Distal cholangiocarcinoma is a malignant tumor that arises from the epithelial cells of the bile duct. Several risk factors associated with cholangiocarcinoma have been identified. Multiple distal cholangiocarcinomas may occur in patients with several risk factors for cholangiocarcinoma. However, synchronous multiple distal cholangiocarcinomas in the absence of risk factors are rare. Here, we presented a case of multiple tumors on the bile duct diagnosed as distal cholangiocarcinoma with synchronous intramural bile duct metastasis.

CASE PRESENTATION: A 67-year-old man was referred to our hospital for evaluation of jaundice. Contrast-enhanced computed tomography revealed an enhanced tumor on the common bile duct. Endoscopic retrograde cholangiography showed bile duct stenosis due to a nodular tumor of the common bile duct. We performed subtotal stomach-preserving pancreaticoduodenectomy under diagnosing distal cholangiocarcinoma. The patient was discharged on the 23rd postoperative day. Macroscopic findings of the resected specimen showed a 27-mm nodular-infiltrating tumor at the middle bile duct and a 3-mm nodular tumor at the lower bile duct. The distance between the tumors was 10 mm. Pathological examination revealed that the larger tumor was primarily composed of poorly differentiated adenocarcinoma, with a moderately differentiated component at the periphery of the tumor. The smaller tumor was entirely composed of poorly differentiated adenocarcinoma, which was similar to the poorly differentiated component of the larger tumor. Additionally, microscopic lymphovascular infiltration was observed in the vicinity of both tumors. These two lesions were separated by nontumoral biliary epithelia without atypia. The results of immunohistochemical staining using CK7/20, MUC1/2, and p53 antibodies substantiated the homology of these tumors. These results suggested that the smaller tumor was synchronous intramural bile duct metastasis of distal cholangiocarcinoma rather than independent multiple lesions.

CONCLUSIONS: In the cases of multiple tumors being synchronously identified on the bile duct, it is crucial to ascertain the relationship between those tumors. Recent developments in immunohistochemical staining and genetic analysis may further facilitate the assessment of the association between multiple distal cholangiocarcinomas.

INTRODUCTION: Pulmonary hamartoma (PH) is the most frequent benign tumor of the lung; however, the induction of malignant tumors and malignant transformation has been reported.

CASE PRESENTATION: The patient was a woman in her 80s.Two transbronchial biopsies were performed for a 20-mm nodule in the S⁸ segment of the right lung, which showed a growing trend, and both were diagnosed as PH. Subsequently, she discontinued her outpatient visits but returned 4 years later with a complaint of blood in her sputum, and the right lung tumor had increased to 66 mm. In addition, a 35-mm tumor was found in the left lung S¹⁺² segment and a 35-mm tumor in the liver, and a diagnosis of cT3N0M1c stage IVB combined with large-cell neuroendocrine carcinoma was made. After chemotherapy, all tumors had shrunk, and no new lesions were detected, so the disease was judged to be oligometastatic, with localized metastases. Therefore, the patient underwent surgical resection of the primary tumor and radiotherapy for the metastases. As a result, the patient was alive and recurrence-free 8 months postoperatively.

CONCLUSIONS: The possibility of accidental malignant transformation of components or surrounding tissues cannot be ruled out in PH, and careful follow-up and aggressive surgical resection should be considered, especially for lesions that increase in size over a short period.

INTRODUCTION: Loss-of-domain in large incisional hernia needs to be addressed by mesh-augmented repair combined with a combination of component separation techniques: progressive pneumoperitoneum (PPP) and chemical component separation with botulinum toxin A. In this case report, successful management of an iatrogenic Staphylococcus aureus peritonitis caused by PPP with nevertheless definitive treatment of a giant loss-of-domain ventral hernia is presented.

CASE PRESENTATION: A female patient with M1-3W3 recurrent incisional hernia with a loss-of-domain of 47% was prepared for definitive ventral hernia repair by chemical component separation with botulinum toxin A-infiltration and PPP via an intraperitoneally placed central venous catheter. A significant increase of inflammatory markers was found after 28 days. An emergency CT scan was performed, which showed the PPP and perihepatic/perisplenic contrast-enhancing fluid collections. Exploratory laparoscopy and laparotomy revealed no bowel perforation but fibrinous peritonitis due to an iatrogenic PPP-catheter-associated peritonitis. Despite the fibrinous peritonitis, we decided to proceed with definitive ventral hernia repair (Rives-Stoppa-Sublay-Herniotomy with transversus abdominis release (left) and anterior component separation (right), 42 × 30 cm permanent polypropylene mesh). Initial calculated antibiotic treatment was performed with piperacillin/tazobactam. Microbiologic examinations revealed Staphylococcus aureus in the intraoperative specimens on postoperative day 1 and the antibiotic treatment was changed to intravenous flucloxacillin for 14 days after surgery. The further hospital stay was uneventful and the patient was discharged on the 20th postoperative day.

CONCLUSIONS: The presented case demonstrates the possibilities in complex ventral hernia repair to achieve a satisfying outcome for the patients. Even in cases with infectious complications, a single-stage procedure might be performed safely and a complete reconstruction of the abdominal wall might be achieved. The risk of chronic mesh infection in contaminated situations, especially during the presence of Staphylococcus aureus, remains uncertain and has to be weighed against possible benefits.

INTRODUCTION: Approximately 20% of patients who contract coronavirus disease (COVID-19) pneumonia require oxygen therapy; of these patients, approximately 5% progress to acute respiratory distress syndrome, necessitating mechanical ventilation. The incidence of secondary infections among patients with COVID-19 is relatively low (16% for bacterial infections and 6.3% for fungal infections), but is predominantly observed in those with severe respiratory failure. Microvascular damage in COVID-19 can also lead to thrombus formation, causing infarctions, and in some cases, necrotizing pneumonia with cavity formation. Pulmonary resection may be necessary in patients who develop pneumothorax or empyema. Management options in complicated COVID-19 continue to evolve and should be individualized. Here, we present a case of Aspergillus empyema with refractory pleural fistula following COVID-19 pneumonia.

CASE PRESENTATION: The patient was hospitalized in the intensive care unit for respiratory failure caused by COVID-19 pneumonia and developed a right pneumothorax 1 month after admission, with a halo sign in the middle lobe on computed tomography. Persistent massive air leakage and hypoxia developed, even with mechanical ventilation. Initially, to reduce the massive air leakage, endobronchial silicone spigot (endobronchial Watanabe spigot: EWS) were placed in the right B2 and middle lobe bronchi to stabilize the severe respiratory failure and septic shock. After EWS placement, the air leak decreased, with gradual improvement in the patient’s multi-organ failure status. Subsequently, the patient underwent a right middle lobectomy and upper lobe wedge resection. Histopathology confirmed an active Aspergillus infection in the resected lung, and voriconazole was administered postoperatively. Air leakage persisted postoperatively, necessitating repeat surgery and, finally, thoracoplasty and negative pressure wound therapy. The patient was eventually discharged with home oxygen therapy.

CONCLUSIONS: This case illustrates the successful treatment of invasive pulmonary aspergillosis with refractory pulmonary fistula and empyema following COVID-19 pneumonia using a combination of endoscopic and surgical interventions. In cases of severe COVID-19 pneumonia, clinicians must remain vigilant for secondary infections, including aspergillosis. EWS placement can be effective in reducing significant air leakage and stabilizing patients’ condition.

INTRODUCTION: Gastric adenocarcinoma with enteroblastic differentiation (GAED) is associated with a poor prognosis because of high rates of liver and lymph node metastases. While systemic chemotherapy is the standard treatment for gastric cancer (GC) with liver metastases, several studies suggest that hepatectomy, when combined with multimodal treatment, may provide a survival benefit. However, the role of surgical resection for GAED with liver metastases remains controversial.

CASE PRESENTATION: A 71-year-old man presented with abdominal pain and nausea. Endoscopy revealed a type 2 tumor at the greater curvature of the gastric body. Contrast-enhanced computed tomography showed thickening and enhancement of the gastric wall, bulky lymph node metastases, and bilobar hepatic lesions, with the largest tumor measuring 60 mm in diameter. Histological examination of the stomach and liver tumors revealed adenocarcinoma composed of cuboidal or columnar cells resembling a primitive intestine-like structure with clear cells. Immunostaining showed heterogeneous cytoplasmic positivity for alpha-fetoprotein and spalt-like protein 4, leading to a diagnosis of GAED with liver metastases. Because the tumor was positive for human epidermal growth factor receptor 2 (HER2), chemotherapy with capecitabine, cisplatin, and trastuzumab was administered. After six cycles, the tumors had significantly decreased in size, and curative-intent surgery was performed, including distal gastrectomy, left lateral sectionectomy, and partial hepatectomy, successfully eradicating all five liver metastases. Histological examination of the liver metastases revealed extensive necrosis and fibrosis with no viable tumor cells. Adjuvant chemotherapy with the same regimen was continued for 1 year. At the time of this writing, the patient had remained recurrence-free for more than 2 years postoperatively.

CONCLUSIONS: We report a rare case of GAED with multiple liver metastases successfully treated with aggressive surgical resection following systemic chemotherapy. Trastuzumab-based chemotherapy may be a viable treatment option for HER2-overexpressing GAED. In addition, radical surgery for GAED with liver metastases might prolong the survival if the chemotherapeutic regimen was effective.

INTRODUCTION: Postoperative Staphylococcus and streptococcal toxic shock syndrome (TSS) are associated with significant morbidity and mortality rates. As a result, surgical awareness is required to recognize and treat TSS appropriately. We report a pediatric case of TSS after thoracentesis for a pneumothorax.

CASE PRESENTATION: A 14-year-old boy was diagnosed with a right pneumothorax and underwent thoracentesis with a trocar catheter. After 2 days, the patient developed a fever, headache, vomiting, and diarrhea. No obvious contamination of the drain puncture wound was observed. He was diagnosed with acute gastroenteritis and received intravenous treatment. On the 4th day after drainage, his blood pressure decreased. Due to suspected septic shock, he was transferred to the intensive care unit and administered antibiotics, immunoglobulin, and a hypertensive agent. His treatment response was good, and his general condition improved relatively quickly. On the 6th day, the patient was discharged from the intensive care unit. Although the air leak from the thoracic drain disappeared on day 3, the drain remained in place until day 8. Blood cultures obtained at the time of septic shock were all negative; however, pleural fluid and thoracic drain tip cultures detected Staphylococcus aureus, and the production of TSS toxin-1 and enterotoxin type C was confirmed. Retrospectively, the patient was diagnosed with TSS triggered by the insertion of a thoracic drain. He was discharged from the hospital on day 11. After discharge, he experienced skin desquamation of the axilla and buttocks. The patient also reported diffuse erythematous eczema on day 3 after drainage. He received antimicrobial therapy for 14 days and recovered fully without any complications.

CONCLUSIONS: TSS can occur after simple, routine procedures such as thoracentesis. Symptoms such as fever, rash, vomiting, and diarrhea should raise concern for TSS and prompt further exploration and cultures, even in benign-appearing postoperative wounds.

INTRODUCTION: Dextrocardia, a condition characterized by the heart’s anomalous positioning to the right, is frequently associated with venous abnormalities, but arterial anomalies are rare. In particular, systemic arterial supply to the posterior basal segment of a normal lung in dextrocardia is an exceedingly rare finding, with only one previously reported case.

CASE PRESENTATION: A 72-year-old female with a history of colorectal and gastric cancer surgeries presented with an abnormal chest X-ray showing a left lung shadow. She was asymptomatic, with no hemoptysis, cough, or dyspnea. Contrast-enhanced chest CT revealed dextrocardia and a thick anomalous artery branching from the aorta, running as the 9th intercostal artery, and supplying the S10 region of the left lung. Venous drainage was through a hypertrophic V10 branch of the pulmonary vein, with no evidence of sequestration or arteriovenous fistulas. Bronchoscopy excluded bronchial anomalies, confirming the diagnosis of anomalous systemic arterial supply to the posterior basal segment of a normal lung. Due to the patient’s carotid arteriosclerosis and risk of fatal hemoptysis, video-assisted thoracoscopic surgery was performed. The anomalous artery was transected, and visibly engorged pleural regions were partially resected. The procedure was completed in 46 min with minimal blood loss. Histopathology showed normal lung tissue with vascular wall thickening. Follow-up imaging after 2 years revealed no vascular abnormalities, and the patient remains healthy 7 years postoperatively, with no aneurysmal changes at the surgical site.

CONCLUSIONS: We experienced a pulmonary artery originating from the aorta with perfusion only in a part of the basal segment of the lung complicated by a right thoracic heart. When preoperative angiography showed only segmental stain, it is considered safe and sufficient to resect only to the extent of the surface vasodilatation grossly during surgery.

INTRODUCTION: Duodenocaval fistula (DCF) is a rare, life-threatening disease with a mortality rate of approximately 40%. There are several types of etiologies for DCF. Among these, duodenal ulcers are the most dangerous, with a mortality rate of 63.6%. This report describes a case of DCF caused by a duodenal ulcer that was successfully diagnosed and treated, and discusses why duodenal ulcer-induced DCF results in severe outcomes, with a review of the literature.

CASE PRESENTATION: A 64-year-old male patient was transferred to our hospital for surgical treatment of DCF. An emergency laparotomy was performed. We opened the abscess cavity, repaired the perforation site and inferior vena cava, and performed gastrojejunostomy. After the operation, anastomotic leakage was suspected. Although we treated him with antibiotics and antifungal drugs, his condition did not improve, and he experienced elevated total bilirubin and inflammation. Therefore, we decided to perform a reoperation on postoperative day (POD) 30, including cholecystectomy, insertion of a C-tube into the common bile duct for biliary drainage, enterostomy, and peritoneal irrigation and drainage. After that, the patient continued antibiotic and antifungal therapy, with periodic drain flushing and replacement. His condition slowly improved, and he was transferred to another facility for rehabilitation on POD 158.

CONCLUSIONS: DCF caused by duodenal ulcers has a higher mortality rate than that caused by other etiologies. Therefore, initiating broad-spectrum antibiotics and antifungal therapy early may be beneficial. Also, it is reasonable to perform simple, rapid, and minimally invasive surgery in an emergency setting. However, even in emergency situations, duodenal decompression, cholecystectomy, and biliary drainage should be performed to prevent anastomotic leakage and biliary complications.

INTRODUCTION: Hepatic angiomyolipoma (AML) is a rare, benign mesenchymal tumor with variable imaging features, often complicating differentiation from malignancy. We report a case of hepatic AML that showed progressive enlargement due to intratumoral hemorrhage, without detectable fat on imaging.

CASE PRESENTATION: A woman in her 70s with no history of chronic liver disease had previously undergone surgery for lung adenocarcinoma and for localized nodular hyperplasia of the liver. Routine follow-up imaging revealed an enlarging liver mass in the right hepatic lobe, leading to her referral for further evaluation. Tumor markers were within normal ranges, and liver function remained intact. Non-contrast CT showed a low-attenuation nodule, and contrast-enhanced CT demonstrated ring-like peripheral enhancement with a hypovascular center. Magnetic resonance imaging showed low signal on T1-weighted images and high signal on T2-weighted images, with no signal loss in opposed-phase imaging. Ultrasonography demonstrated a low echogenicity within the tumor and high echogenicity in the surrounding area, with no clear contrast effect. The preoperative diagnosis suggested either a hematoma or a necrotic nodule. Given the progressive growth and inconclusive imaging, malignancy could not be excluded. A laparoscopic hepatectomy was performed for definitive diagnosis. The resected tumor was a 2.3 × 2.0 × 1.4 cm well-demarcated, light brown mass with areas of hemorrhage and cystic change. Histopathology confirmed hepatic AML with tumor hemorrhage and extramedullary hematopoiesis.

CONCLUSIONS: Hepatic AML may exhibit progressive growth despite lacking typical imaging features such as intratumoral fat or vascularity, making preoperative diagnosis difficult. In cases where malignancy cannot be ruled out, surgical resection should be considered after careful evaluation of both benign and malignant possibilities.

INTRODUCTION: Situs inversus totalis is a rare congenital disorder defined as mirror-image transposition of the thoracoabdominal organs, and surgical strategies remain controversial owing to the associated anatomical abnormalities. Although laparoscopic and robot-assisted surgeries are gaining popularity, no reports have been published on robot-assisted gastrectomy and sigmoid colectomy for situs inversus totalis at the same time.

CASE PRESENTATION: A 77-year-old woman with situs inversus totalis presented to our hospital with type 0-IIa+IIc sigmoid colon cancer and type 0-IIc gastric cancer. Therefore, we decided to perform robot-assisted gastrectomy and sigmoid colectomy. The port positions were the same for both procedures, and the robot rolled in from the opposite side of the body. The surgery was successful, and the postoperative course was uneventful.

CONCLUSIONS: While we did not experience any challenges during distal gastrectomy, we experienced difficulty in dissecting toward the root of the inferior mesenteric artery during sigmoid colectomy. To address this problem, port transportation can be improved.

INTRODUCTION: Intradiaphragmatic abscesses are extremely rare; therefore, making a correct preoperative diagnosis is difficult. Furthermore, their pathogenesis is not well understood because of the limited number of reported cases.

CASE PRESENTATION: A 62-year-old Japanese male who had undergone cholecystectomy for acute cholecystitis complicated by cholelithiasis 1 year previously presented to our hospital with a fever and right chest pain. Laboratory investigations revealed an elevated inflammatory response. Preoperative computed tomography suggested an intra-abdominal abscess and right pyothorax, and surgical drainage was performed via laparoscopic and thoracoscopic approaches because there was no laboratory improvement after intravenous antibiotic therapy. Intraoperative findings showed a localized bulge in the right diaphragmatic dome without an abscess in the liver or the subdiaphragmatic area. A whitish pus was drained through an incision. By contrast, in the thoracic cavity, serous pleural effusion, fibrin precipitation, and localized bulge on the same diaphragmatic site as the abdominal bulge were found without abscess formation. Pus was not drained by puncture aspiration, and no incision was made. The pus culture was positive for Escherichia coli. A combined abdominal and thoracic approach allows for correct diagnosis and appropriate treatment. The patient’s general condition improved postoperatively, and he remained well without evidence of recurrence of the intradiaphragmatic abscess 18 months later for follow-up chest computed tomography.

CONCLUSIONS: Despite the extremely rare nature of the disease, if an intradiaphragmatic abscess is suspected preoperatively, a combined abdominal and thoracic approach may be useful for making the correct diagnosis and carrying out appropriate treatment.

INTRODUCTION: Postoperative chylothorax after thoracic surgery is relatively rare, and cardiac tamponade accompanied by the former is a scarce phenomenon. Although there have been scarce reports of such cases in cardiac surgery, reports on general thoracic surgery are exceedingly rare.

CASE PRESENTATION: A 57-year-old male with suspected lung cancer underwent right upper lobectomy and selective mediastinal lymph node dissection. Postoperatively, he developed chylothorax that was unresponsive to conservative management, and thoracic duct ligation was planned for postoperative day 13. However, on postoperative day 12, he experienced cardiopulmonary arrest secondary to chylopericardial tamponade. Although cardiac rhythm was restored by pericardiocentesis, resuscitation required 80 minutes. The patient ultimately died of multiple organ failure on postoperative day 23.

CONCLUSIONS: To our knowledge, this is the first report of postoperative death due to chylopericardial tamponade accompanied by postoperative chylothorax. Although this is a scarce complication, it can be fatal, and thoracic surgeons who perform pulmonary resection with mediastinal lymph node dissection should be aware of this phenomenon. In cases of postoperative chylothorax with concurrent pericardial effusion, the possibility of developing chylopericardial tamponade should be considered, and active consideration of pericardial drainage is recommended.

INTRODUCTION: Non-absorbable sutures or Teflon pledgets (model number: 00801741041341, Bard, Franklin Lakes, NJ, USA) are sometimes used for protection of the bronchial stump to prevent bronchial fistula. However, there have been reports of foreign body-related bronchial granulation in the distant phase. Treatment of this rare complication is challenging, and there are no reports in the literature of cases that ultimately underwent curative surgical excision.

CASE PRESENTATION: A 63-year-old man underwent a right lower lobectomy with ND2a-2 for typical pulmonary carcinoid 20 years ago. Twelve years after the operation, the right intermediate bronchus gradually became obstructed with granulation tissue from the right lower bronchial stump. Therefore, we eliminated the obstruction and placed a 2-cm Dumon stent (model number: 20300BZY00250000, Novatech SA, La Ciotat, France) in the intermediate bronchus. However, the inner lumen of the stent gradually became filled with the granulation tissue, and 6 years after the stenting, the patient was referred to the hospital owing to massive hemoptysis and obstructive pneumonia. Although transcatheter bronchial arterial embolization was performed for a pseudoaneurysm, blood-tinged sputum remained present, and aspiration pneumonia had spread to the right upper lobe. Bronchoscopy showed that a non-absorbable suture, which was used for the protection of the bronchial stump 20 years ago, was buried in the obstructive tissue. After antibiotic treatment for the pneumonia, we performed a right middle lobectomy as well as the removal of the stent and the threads as a curative treatment.

CONCLUSIONS: Non-absorbable suture sometimes causes granulation tissue in the distant phase, and absorbable sutures are preferable for the bronchial stump. For the treatment, complete excision at an appropriate time is required based on the severity of the symptoms.

INTRODUCTION: Colon leiomyosarcoma (CLMS) is an extremely rare neoplasm and the information regarding its clinical characteristics and specific treatment was still unclear.

CASE PRESENTATION: A 73-year-old female who had been diagnosed with transverse CLMS underwent laparoscopic surgery. The resected specimen showed that the tumor contained proliferation of spindle-shaped cells and arranged in fascicular pattern, which was immunohistochemically positive for smooth muscle actin and desmin. Moreover, the tumor bottom was not continuous with the muscularis propria and had a clear border in the submucosa layer. According to these findings, we finally diagnosed it as primary CLMS arising from the muscularis mucosa (MM). No recurrence was noted 24 months after surgery.

CONCLUSIONS: This literature demonstrates CLMS arising from MM and suggests that its pathological diagnosis is associated with disease prognosis.

INTRODUCTION: Choroidal metastasis from colorectal cancer is extremely rare, accounting for approximately only 4% of all choroidal metastases. However, with the increasing incidence and improved survival rates of colorectal cancer, the importance of diagnosing and treating ocular metastases is growing. We report a case of choroidal metastasis from colorectal cancer and review the relevant literature.

CASE PRESENTATION: A 67-year-old man underwent curative surgery and adjuvant chemotherapy for ascending colon cancer. Two years later, pulmonary recurrence was detected and surgically resected. At 2 years and 5 months postoperatively, he developed visual impairment in the left eye, which led to the diagnosis of choroidal metastasis. A combination of systemic chemotherapy and local radiotherapy resulted in tumor shrinkage and relief of ocular pain. With additional local treatments administered in response to subsequent recurrences, the patient achieved long-term survival—5 years and 6 months after surgery and 3 years after the diagnosis of choroidal metastasis. A review of 22 reported cases of choroidal metastasis from colorectal cancer published since 2000 revealed that most patients had multi-organ metastases at the time of diagnosis. The average survival following the diagnosis of ocular metastasis was 10.4 months, indicating a poor prognosis. By contrast, local treatments—such as radiotherapy and intravitreal injections—contributed to symptom relief and the maintenance of quality of life. This case represents a valuable example of long-term survival achieved through combined local therapies.

CONCLUSIONS: Although choroidal metastasis from colorectal cancer is rare, clinical management should consider the possibility of ocular involvement. A multidisciplinary approach combining systemic therapy with local treatments is essential for maintaining quality of life and prolonging survival.

INTRODUCTION: Pembrolizumab was approved for the treatment of microsatellite instability (MSI)–high pancreatic cancer that is unresponsive to systemic chemotherapy. However, pancreatic cancer has a low prevalence of MSI-high status (<1%). We report a rare case of MSI-high pancreatic tail cancer successfully treated with pembrolizumab, which enabled conversion surgery to be performed.

CASE PRESENTATION: A 78-year-old male patient received the diagnosis of unresectable metastatic (UR-M) pancreatic tail cancer with para-aortic and anterior mediastinal lymph node metastases. Tests found high MSI due to the loss of MSH2 and MSH6 expression. Following 6 courses of pembrolizumab, he achieved a partial response. Pembrolizumab was discontinued after immune-related renal dysfunction developed during the 7th course. Fluorodeoxyglucose positron emission tomography/computed tomography demonstrated decreased uptake in the anterior mediastinal and para-aortic lymph nodes, allowing a radical resection to be performed. The patient underwent a radical antegrade modular pancreatosplenectomy with a left adrenalectomy and para-aortic lymph node sampling. Currently, at postoperative month 6, he is alive and recurrence-free. The present case is an extremely rare instance of MSI-high, unresectable pancreatic cancer that was removed by curative resection after pembrolizumab therapy.

CONCLUSIONS: The present rare case of conversion surgery for MSI-high UR-M pancreatic tail cancer, achieving a pathological partial response after pembrolizumab treatment, highlights the potential of pembrolizumab against this specific molecular subtype of pancreatic cancer and underscores the clinical significance of proactively testing for MSI to identify candidates for immunotherapy and curative conversion surgery.

INTRODUCTION: Although seminomas typically arise in the testes, primary mediastinal seminomas are classified as extragonadal germ cell tumors. Diagnosis is often challenging and requires not only blood tests and imaging but also a tumor biopsy. However, diagnosis may be particularly difficult when the tumor shows nonspecific pathological features or is accompanied by granulomatous changes.

CASE PRESENTATION: The patient was a 25-year-old man who had been experiencing labored breathing when leaning forward for the past month. Physical examination revealed distended jugular veins and neck edema. Chest computed tomography revealed an irregular mass measuring 80 mm in the anterior mediastinum, suggesting invasion of the superior vena cava. Additionally, fluorodeoxyglucose-positron emission tomography showed high accumulation in the same area, with a maximum standardized uptake value of 11.3. A tumor biopsy was performed under thoracoscopic guidance for definitive diagnosis. Histopathological examination of the resected specimen revealed a seminoma with granulomatous changes. Based on these findings, a diagnosis of anterior mediastinal seminoma with superior vena cava syndrome was made. It was classified as having a good prognosis, and the patient received three courses of induction chemotherapy with etoposide, cisplatin, and ifosfamide. Complete remission was achieved. Since then, the patient has been monitored every 3 months, with no recurrence or metastasis observed for approximately 2 years.

CONCLUSIONS: Immunohistochemical analysis plays a crucial role in the accurate diagnosis of mediastinal seminomas, especially in cases with unusual histological features such as granulomatous changes. Recognizing the immunoprofile of seminomas and differentiating them from thymomas and lymphomas is essential for avoiding diagnostic pitfalls.

INTRODUCTION: A staple line granuloma (SG) in the lung, which arises adjacent to a staple line after lung surgery, is often difficult to differentiate from a stump recurrence. We report two cases of lung tumors that were suspected of being SGs, and the tumors resolved after the use of oral tranilast.

CASE PRESENTATION: Case 1 is a 71-year-old woman who underwent a right S8 segmentectomy for lung adenocarcinoma (pT1miN0M0, stage IA1). A follow-up chest computed tomography (CT) scan, which was performed 9 months after surgery, revealed a mass adjacent to the staple line. The lesion disappeared by the 3rd month after administration of tranilast with no recurrence. Case 2 is a 70-year-old woman who underwent wedge resection for metastatic lung cancer originating from renal cancer. A follow-up chest CT scan, which we obtained 8 months after surgery, revealed a nodule adjacent to the staple line. The lesion disappeared by the 4th month after administration of tranilast with no recurrence.

CONCLUSIONS: Administration of tranilast can be a safe and effective diagnostic treatment for SG, when the treatment is performed with strict imaging follow-up and histologic biopsy in mind.

INTRODUCTION: Intussusception in adults is a rare condition, and gastric cancer prolapsing into the duodenum is an even rarer phenomenon. We present a case of early gastric cancer originating in the gastric body with duodenal intussusception and discuss the clinical considerations based on the patient’s overall condition and existing literature.

CASE PRESENTATION: A 69-year-old man with a 30-mm tumor arising from the posterior wall of the gastric body was scheduled for elective surgery. During hospitalization for diabetes mellitus management, he developed sudden epigastric pain and nausea. Upper gastrointestinal endoscopy revealed tumor prolapse into the duodenum, leading to a diagnosis of ball valve syndrome. After successful endoscopic reduction, open local gastrectomy was performed. Pathological examination confirmed a well-differentiated tubular adenocarcinoma, classified as pT1b (SM2) N0M0, pStage IA.

CONCLUSIONS: Gastric cancer with duodenal intussusception is often early-stage and characterized by well-differentiated tubular adenocarcinoma. Depending on the patient’s condition, endoscopic resection or limited surgical resection may be viable treatment options for this rare condition.

INTRODUCTION: Hepatoid carcinoma (HC) is a rare type of malignant tumor that shares similar serological, morphological, and immunohistochemical features with hepatocellular carcinoma. Pancreatic HC exhibits aggressive biological behavior and is classified as pure type, combined type, and mixed type. Unlike the pure type, the combined and mixed types refer to HC with other histological components. While the most common component is the neuroendocrine tumor (NET), no case of coexistence of neuroendocrine carcinoma (NEC) and NET with hepatoid differentiation has been reported. We herein report an extremely rare case of coexisting NEC and NET of the whole pancreas with hepatoid differentiation.

CASE PRESENTATION: A 15-year-old woman had epigastric pain and impaired glucose tolerance, without any medical or family history. Computed tomography (CT) revealed a 6.4-cm mass in the pancreatic head, an enhanced mass throughout the pancreas, and a 1.0-cm liver lesion. Positron emission tomography (PET)/CT and somatostatin receptor scintigraphy (SRS) suggested a NET in the pancreatic body and tail, and a NEC in the pancreatic head. Biopsies confirmed NEC in the pancreatic head and liver with possible hepatoid differentiation. The patient underwent combination chemotherapy with carboplatin and etoposide. Due to the partial response achieved with chemotherapy, which led to significant tumor shrinkage on CT and no uptake on PET/CT in the pancreatic head tumor, the patient proceeded with conversion surgery, including a total pancreatectomy with portal vein resection and partial hepatectomy. However, serum α-fetoprotein (AFP) levels rapidly rose, and multiple liver metastases of NEC were detected on CT at 5 months after surgery. Liver metastases worsened despite further chemotherapy. The patient died 10 months after surgery.

CONCLUSIONS: We herein present an extremely rare case of coexisting NET and NEC of the whole pancreas with hepatoid differentiation. Due to a remarkable response to chemotherapy, conversion surgery was performed. However, early recurrence of liver metastases accompanied by a rapid increase in serum AFP levels occurred, and the prognosis was poor. Pancreatic HC should be considered when encountering a bulky tumor of the pancreas with elevated serum AFP levels, and further case series and analysis are needed to determine the appropriate treatment strategy.

INTRODUCTION: Idiopathic multicentric Castleman disease (iMCD) is a rare lymphoproliferative disorder characterized by systemic inflammation and chronic immunosuppression. When solid malignancies such as gastric cancer arise in patients with iMCD, perioperative management becomes particularly challenging due to nutritional decline, reactive lymphadenopathy, and elevated surgical risk.

CASE PRESENTATION: A 75-year-old man with a 26-year history of suspected iMCD treated with low-dose corticosteroids presented with epigastric discomfort. Endoscopy revealed a Borrmann type 2 lesion, and biopsy confirmed poorly differentiated adenocarcinoma. CT showed mild lymphadenopathy along the lesser curvature and left gastric artery, as well as systemic involvement. Inguinal node biopsy confirmed polyclonal plasma cell proliferation consistent with iMCD. The patient also met the Asian Working Group for Sarcopenia (AWGS) criteria for severe sarcopenia. A multidisciplinary team initiated preoperative respiratory rehabilitation, nutritional support, and resistance exercise therapy. Curative distal gastrectomy with D2 lymphadenectomy was performed without complications. Histopathology revealed pT2N0M0 (pStage IB) disease. Tocilizumab was started 3 months postoperatively, and the patient remains recurrence-free at 24 months.

CONCLUSIONS: This case highlights that, even in patients with long-standing iMCD and sarcopenia, carefully staged multimodal perioperative care—including accurate nodal evaluation and individualized systemic therapy—can enable successful curative surgery for advanced gastric cancer.

INTRODUCTION: Soft tissue metastasis of breast cancer is very rare. Specifically, metastasis to the upper arm has only been reported in 10 cases, including this one, to the best of our knowledge. Distant lymph node metastasis of breast cancer is also infrequent, with only one documented case of brachial lymph node metastasis.

CASE PRESENTATION: We report a case of soft tissue or lymph node metastasis in the right upper arm, diagnosed 3 years after surgery for right breast cancer. The patient, a 79-year-old woman, was receiving postoperative hormone therapy for right breast cancer. She presented with edema and numbness in the right upper arm during a routine follow-up examination 3 years post-surgery. Ultrasonography revealed a 20 mm mass in the right brachial muscle, which was diagnosed as adenocarcinoma via fine-needle aspiration, suggesting breast cancer metastasis. Further examination showed that the mass was in close proximity to the nerves and veins, but no definitive evidence of invasion was observed. Surgical resection was performed. The tumor was particularly adherent to the nerve, complicating resection. While no gross residual tumor was noted, histopathological analysis indicated positive surgical margins. After surgery for soft tissue or lymph node metastasis, the patient continued hormone therapy postoperatively. However, approximately 1 year and 3 months later, tumor recurrence at the resection site and skin metastasis were observed. Consequently, hormone therapy was modified, and oral cyclin-dependent kinase 4/6 (CDK4/6) inhibitors were initiated.

CONCLUSIONS: Metastasis of breast cancer to soft tissue and the brachial lymph nodes is extremely rare. Diagnosis may be delayed in asymptomatic cases, and when metastasis is in close proximity to surrounding structures, such as the nerves, histological diagnosis can be challenging. Metastatic soft-tissue tumors are associated with a poor prognosis; therefore, early diagnosis and appropriate multimodal treatment are crucial.

INTRODUCTION: Gastric neuroendocrine carcinoma (G-NEC) is a rare but highly aggressive malignancy that often presents with distant metastases and significantly worsens prognosis. Recent studies have suggested that conversion surgery after chemotherapy may improve outcomes in initially unresectable gastric cancers; however, evidence regarding its application in G-NEC remains limited. We report a rare case of advanced G-NEC with multiple liver metastases that was treated with R0 resection through conversion surgery after chemotherapy.

CASE PRESENTATION: A 73-year-old man presented with postprandial heartburn and abdominal pain. Upper gastrointestinal endoscopy revealed a type 3 tumor with submucosal tumor-like elevation. Endoscopic biopsy confirmed G-NEC, and computed tomography revealed lymph node enlargement and seven liver lesions, leading to a diagnosis of T2N1M1 (Stage IVB). The patient was initially treated with etoposide and cisplatin (EP) for unresectable G-NECs. Following 13 courses of chemotherapy, significant tumor reduction was observed, with the disappearance of lymph node metastasis and marked shrinkage of liver metastases. Because all lesions, including liver metastases, were deemed resectable, conversion surgery was performed. The surgical approach consisted of laparoscopic distal gastrectomy with D2 lymph node dissection, laparoscopic left medial hepatic segmentectomy, partial hepatectomy, and cholecystectomy. Pathological examination revealed residual tumor cells at the primary site; however, no viable tumor cells were detected in the lymph nodes or liver resection specimens, indicating a marked response to chemotherapy. R0 resection was confirmed at the final staging of T2N0M0 (Stage IB).

CONCLUSIONS: This case highlights the fact that effective chemotherapy may render initially unresectable G-NECs amenable to curative conversion. Successful R0 resection and a substantial response of liver metastases to EP chemotherapy demonstrated the potential viability of this approach in achieving improved patient outcomes.

INTRODUCTION: Thymomas have the potential to locally invade and metastasize, occasionally infiltrating adjacent structures, such as the great vessels and the heart. Although direct extension is the primary mechanism of vascular invasion, rare cases of intravascular growth have also been reported.

CASE PRESENTATION: We present the case of a 50-year-old woman diagnosed with a thymoma that extended intraluminally into the left brachiocephalic vein (LBCV), forming a tumor thrombus. The patient was referred to our hospital after chest computed tomography (CT), which revealed an anterior mediastinal tumor with a filling defect adjacent to the superior aspect of the tumor. Initially, the defect was thought to be a blood clot because of the preserved vascular wall structure. However, follow-up CT scans conducted 2 weeks later revealed persistence of the defect and a slight increase in size, leading to the diagnosis of a tumor thrombus. Further imaging, including contrast-enhanced CT and magnetic resonance imaging, confirmed thymoma invasion of the LBCV, necessitating surgical intervention. The patient underwent a median sternotomy and tumor resection with combined partial resection of the LBCV and right upper lobe. Intraoperatively, a dilated thymic vein continuous with the tumor was identified. The tumor thrombus was visible through the LBCV wall, aiding in the determination of its extent. The LBCV was clamped proximally and distally, and the dilated thymic vein was ligated and divided. Subsequently, thymectomy encompassing the tumor and partial resection of the LBCV wall were performed to remove the thrombus. Microscopically, the tumor was classified as a type B2 thymoma. No evidence of continuity between the tumor thrombus and the thymic vein was observed. No postoperative complication was observed. Nine months after surgery, the patient experienced recurrence with pleural dissemination and underwent resection.

CONCLUSIONS: Thymomas can invade vessels through intravascular growth, and contrast-enhanced CT is important for accurately diagnosing such cases. In this instance, preoperative identification of the tumor thrombus enabled a comprehensive surgical approach, resulting in complete resection of the tumor and thrombus, without the need for embolization. This case underscores the significance of meticulous imaging and surgical planning in the management of complex thymomas to ensure optimal patient outcomes.