A 67-year-old man visited our hospital with a complaint of dysphagia. Upper gastrointestinal endoscopy revealed a type 2 tumor surrounded with a type 0-IIc tumor in the lower thoracic esophagus, and biopsy revealed squamous cell carcinoma and neuroendocrine cell carcinoma. With a diagnosis of lower thoracic esophageal carcinoma (cT3N2M0 cStage III), the patient underwent thoracoscopic subtotal esophagectomy with gastric tube reconstruction via a retrosternal route, along with two-field and #101 lymph node dissection after two courses of FP (5-fluorouracil+CDDP) therapy as neoadjuvant chemotherapy. Two months after surgery, CT revealed multiple lymph node metastases and liver metastases. IP (CPT-11+CDDP) therapy was given based on the assumption that the metastases were of neuroendocrine cell carcinoma, but the patient developed Trousseau’s syndrome. IP therapy was continued, but the metastatic disease progressed and the patient died 7 months after surgery. We report this case as an example of mixed neuroendocrine and non-neuroendocrine neoplasms of the esophagus with rapid progression of postoperative metastatic recurrence accompanying Trousseau’s syndrome.

A 79-year-old woman underwent laparoscopic distal gastrectomy and Roux-en-Y reconstruction for gastric cancer. Gastrojejunal anastomosis was performed with the overlap method. The patient suffered vomiting on postoperative day (POD) 3. Upper gastrointestinal endoscopy performed on POD 8 showed jejunal mucosa protruding into the remnant stomach, and the patient was diagnosed with intussusception in the gastrojejunal anastomosis. Endoscopic repositioning by pushing the edge of the jejunum was unsuccessful, and thus, surgical repositioning was performed on POD 22. Intraoperative findings confirmed that the stump of the ascending jejunal limb was invaginated into the remnant stomach. The jejunal intussusception could not be repositioned by the Hutchinson technique; therefore, the ascending jejunum was resected and a new gastrojejunal anastomosis was constructed. There are few reports of intestinal invagination at the anastomosis of the jejunum after distal gastrectomy. This case suggests that immediate reoperation should be considered when such an invagination is diagnosed.

A 64-year-old man was admitted to our hospital with a chief complaint of tarry stools. He had a history of distal gastrectomy for duodenal ulcer 40 years ago. Emergency upper endoscopy was performed due to suspicion of bloody contents in the remnant stomach on CT, and a raised lesion was found on the anterior wall of the lesser curvature of the remaining stomach. Bleeding from the ulcer at the apex was observed, and hemostasis was performed by soft coagulation. Later endoscopic US showed that the lesion was a submucosal tumor with inner hypoechoic areas, which was difficult to differentiate from a gastrointestinal stromal tumor or leiomyoma. Because the tumor was unstable, endoscopic fine needle aspiration cytology was not performed. The tumor was resected by laparoscopic endoscopic cooperative surgery (LECS) about 8 months after the initial diagnosis. The pathological findings revealed cystic dilated glands with no atypia proliferated under the mucosa, and the tumor was diagnosed as a hamartomatous inverted polyp (HIP). We report this case as an example of HIP in a remnant stomach that was discovered after hemorrhage and resected by LECS.

The patient was a 74-year-old man who became easily agitated and had abnormal behavior during his vit to our hospital for treatment of chronic myelogenous leukemia, and he was diagnosed with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. His symptoms improved after treatment with steroid pulse and immunoglobulin therapy, and he was subsequently diagnosed with gastric cancer after a systemic examination. Since the pathological diagnosis after ESD resection was adenocarcinoma with neuroendocrine carcinoma and lymphatic invasion, laparoscopic distal gastrectomy (D1+) was performed as a curative resection. Anti-NMDAR encephalitis is caused by specific antibodies to NMDAR. Many patients with this disease have a tumor, including carcinoma, and tumor resection is effective for treatment, in addition to steroid pulse and immunoglobulin therapy. Careful systemic examinations are required to find tumors in patients with anti-NMDAR encephalitis.

A 49-year-old male presented to our hospital with a liver tumor. CT revealed a slightly enhanced liver tumor of 30 mm in diameter in segment 6. The patient had a history of surgery for ameloblastoma 24 years ago and for metastatic lung tumors 4 years ago. Thus, laparoscopic partial liver resection was performed based on medical guidelines. Pathologically, the tumor was diagnosed as metastatic ameloblastoma. This case serves as an important reminder to consider metastatic ameloblastoma in an investigation of possible causes of a liver tumor after treatment for ameloblastoma.

A 69-year-old man had undergone ileocecotomy and postoperative chemotherapy for multiple liver metastases. Thereafter, he was admitted to our hospital for percutaneous transhepatic portal vein embolization (PTPE) and liver resection. Two days after PTPE, a coronavirus disease 2019 (COVID-19) cluster occurred at the hospital and the patient developed COVID-19 four days after PTPE. His respiratory condition worsened just before use of a respirator, despite treatment with antiviral drugs, steroids, and anticoagulants in the early period. His symptoms improved and oxygen administration was stopped at four weeks after onset, and his general condition had improved by eight weeks after onset. Therefore, we reassessed the preoperative examination and performed extended right hepatectomy, partial hepatectomy, and microwave coagulation therapy. These procedures did not cause respiratory disturbance, clotting, or marked liver damage after surgery. This case shows that missing the opportunity of curative surgery can be avoided after COVID-19 with careful consideration of patient and social factors. This is an important observation during the COVID-19 pandemic.

A 55-year-old man was admitted to our hospital with a complaint of abdominal distension. Contrast-enhanced CT showed a 14-cm mass in the upper left abdomen and a 17-cm mass in the pelvic cavity, as well as numerous intra-abdominal nodules. A percutaneous needle biopsy was performed for the upper abdominal tumor, and gastrointestinal stromal tumor (GIST) with multiple peritoneal dissemination was diagnosed. Imatinib mesylate therapy was started, and after two years of this therapy, the tumors in the upper left abdomen and pelvic cavity had shrunk to 6 cm and 8 cm, respectively. Five years after the start of the therapy, exploratory laparoscopy and biopsy of the disseminated lesions were performed. The biopsy showed no residual tumor and PET-CT showed no accumulation. We judged that radical resection was possible, and surgery was performed. A histopathological examination revealed a 5-mm c-kit positive tumor in the muscularis propria of the upper jejunum. All other lesions were calcification and fibrous tissue only. Postoperative imatinib was continued and there has been no recurrence for 24 months after the surgical resection.