We report the case of a 76-year-old man who had undergone thoracoscopic subtotal esophagectomy for lower thoracic esophageal cancer three years ago. He was admitted to our hospital because of persistent leakage of intestinal fluid from the site of removal of the jejunostomy tube. The fistula was closed endoscopically using clips. Four days later, the patient complained of abdominal distention and breathlessness, which then progressed to respiratory distress and tachycardia, especially while sitting. A CT scan showed a large amount of free air in the abdominal cavity and bilateral small pneumothorax. Fluoroscopy showed no leakage. We performed abdominal drainage for decompression and inserted a right thoracic tube. Abdominal distention continued until placement of a left thoracic tube. Pneumoperitoneum was thought to be secondary to pneumothorax because of communication between the thoracic and abdominal cavities caused by esophageal cancer surgery. Thus, we diagnosed the case as tension pneumoperitoneum secondary to spontaneous pneumothorax. This case shows that the possibility of communication between the thoracic and abdominal cavities must be taken into account after surgery for esophageal cancer.

A 70-year-old woman presented to her family doctor with sudden upper abdominal pain. Blood tests showed an elevated inflammatory response, and she was referred to our hospital for consultation. Abdominal CT showed a 66-mm area of hyperintensity in the round ligament of the liver, and we diagnosed abscess of the round ligament of the liver. Percutaneous abscess drainage and antibiotic administration resulted in prompt resolution of symptoms and normalized the inflammatory response. One month after diagnosis, we performed single-port laparoscopic surgery. In this surgery, we placed a port in the right lower abdomen and resected the round ligament of the liver along with a 40-mm large abscess scar. The patient had severe periodontitis, and since the abscess culture revealed oral resident bacteria, we assumed that the infection represented transarterial infection of periodontal origin. Abscess of the round ligament of the liver is rare, and surgical resection is recommended for treatment. We safely conducted a less invasive single-port laparoscopic surgery for giant abscess of the ligament of the liver by performing the surgery after percutaneous drainage and antibiotic treatment.

A 61-year-old man underwent right trisegmentectomy combined with diaphragmatic resection for hepatocellular carcinoma (HCC) at age 52, and thoracoscopic left upper and lower lobe partial resection for lung metastases at age 56. At age 59, PIVKA-II was elevated, transcatheter arterial chemoembolization was performed for diagnosis of intrahepatic recurrence, and PIVKA-II also decreased. In the next year, PIVKA-II re-elevated and a tumor of 5 cm was found in the right gastrocnemius muscle. Needle biopsy was performed for diagnosis of skeletal muscle metastasis. Extended tumor resection and latissimus dorsi musculocutaneous flap and skin graft were performed. The histopathological diagnosis was metastasis of HCC, moderately to poorly differentiated, and venous invasion was observed. The patient is alive without recurrence 16 months after the last surgery. While skeletal muscle metastasis of HCC is rare, this case shows that a favorable prognosis is possible after tumor resection.

A 69-year-old man who had undergone endoscopic sphincterotomy and cholecystectomy for choledocholithiasis and cholelithiasis 17 years earlier visited his private doctor with a complaint of upper abdominal pain and elevated liver enzymes. ERCP revealed an irregular stenosis of 1 cm in diameter in the lower bile duct. Repeat biopsies were obtained from the stenosed area of the bile duct, but malignant cells could not be confirmed histologically. However, malignant biliary stenosis was strongly suspected, based on imaging studies. Therefore, we performed subtotal stomach-preserving pancreaticoduodenectomy with lymph node dissection. The resected specimen had formed a thickened wall in the intrapancreatic lower bile duct macroscopically, and histopathological findings revealed thickened fibrous tissue with prominent proliferation of nerve fibers without malignancy. The tumor cells were S-100- and neurofilament-positive, immunohistochemically. The final pathological diagnosis was a neuroma of the intrapancreatic bile duct. Neuromas located in the intrapancreatic bile duct are very rare and these tumors are difficult to diagnose and treat.

A 68-year-old woman was referred to our hospital for evaluation of abdominal pain. CT images revealed a 40-mm mass in the body and head of the pancreas, and a diagnosis of unresectable pancreatic cancer was made due to involvement of the portal vein (PV) and splenic vein and abutting to the celiac artery, common hepatic artery and splenic artery at >180°. After 6 cycles of chemotherapy, CT showed a partial response and tumor markers normalized; thus, total pancreatectomy with celiac axis resection (TP-CAR) with PV resection was planned as a conversion surgery. TP-CAR basically requires arterial reconstruction for hepatic flow. However, planned TP-CAR without arterial reconstruction was performed due to preservation of the aberrant arteries. Pathological findings revealed R0 resection, and there was no recurrence at 16 months follow-up. We report here a successful case of TP-CAR without arterial reconstruction due to preservation of the aberrant arteries.

We report a resected case that was diagnosed as an intraductal tubular carcinoma (ITC) of the pancreas preoperatively. A 67-year-old man was referred to our hospital. CT showed a dilated main pancreatic duct (MPD) with an intraductal tumor. Dilatation of the papilla Vater and mucus discharge from the orifice of the major papilla were not detected on ERCP. MRCP revealed a cork-of-wine-bottle appearance. EUS showed an intraductal mass of approximately 17 mm, occupied the MPD. A biopsy revealed tub1 and tub2. The preoperative diagnosis was ITC and pylorus preserving pancreaticoduodenectomy was performed. A histopathological examination showed that solid proliferating tumor cells with tubular formation filled the entire MPD. Anaplastic change was detected in the part of the tumor. Immunohistological findings showed that the tumor cells were positive for MUC1 and MUC6, and negative for MUC2 and MUC5AC. The case was diagnosed as ITC, pT1N1aM0: Stage IIB, according to the Seventh Edition of the General Rules for the Study of Pancreatic Cancer in Japan. The patient is doing well 5 years after surgery, without recurrence.

A 80-year-old woman visited our hospital with a complaint of abdominal pain and vomiting. Her abdomen showed muscular guarding with tenderness in the right lower quadrant. Abdominal CT showed an area of poor contrast of the small intestine in the right lower abdomen with surrounding ascites. We diagnosed strangulation ileus in the small intestine and performed emergency surgery. In surgery, the cord was found to be continuous from the posterior wall at the umbilicus into the abdominal cavity, and the small intestine was strangulated. The strangulation was released when the cord was resected. The cord was continuous to the anterior of the ileal mesentery about 20 cm proximal from the ileocecal valve. No Meckel’s diverticulum was found. Histopathological examination revealed that the cord contained an artery and vein, and was diagnosed as vitelline vascular remnants. Vitelline vascular remnants without Meckel’s diverticulum are often found in the presence of ileus, making diagnostic imaging and preoperative diagnosis difficult. Prophylactic resection of vitelline vascular remnants may be desirable if a diagnosis can be made or if they are discovered by chance during surgery.

The patient in the first case was a 73-year-old man diagnosed with cT4b (duodenum, kidney) N2M1a (PUL) cStage IV ascending colon cancer. He was treated with right hemicolectomy, right nephrectomy, and pancreas-sparing duodenectomy (PSD). The second case was a 73-year-old woman diagnosed with cT4b (duodenum, kidney) N2M0 cStage IIIb ascending colon cancer. She was also treated with right hemicolectomy, right nephrectomy, and PSD. Both cases had massive duodenal invasion. However, the tumor was completely resected through the combination with the PSD procedure. No severe complications occurred in either case. The conventional surgical strategy for locally advanced ascending colon cancer with massive duodenal invasion is a combination of pancreatoduodenectomy (PD) and colectomy. However, surgeons must be aware that with PD, there are high risks for severe complications. PSD can be performed in cases with massive duodenal invasion. The procedure may reduce postoperative complications and preserve pancreatic function, compared with PD. Therefore, PSD should be considered in colon cancers with massive duodenal invasion.

A 67-year-old woman underwent surgery and postoperative radiation therapy for cervical carcinoma 38 years ago. She underwent colonoscopy at another hospital because a physical examination revealed positive fecal occult blood. Radiation proctitis and a slight elevated lesion in the same area were detected, and a pathological study of the biopsy sample revealed a group 3 finding. She was referred to the Department of Gastroenterology at our hospital. Endoscopic treatment was difficult due to poor intestinal mobility, poor endoscopic manipulation, and the unclear extent of the lesion. A pathological study of the biopsy performed 6 months after colonoscopy revealed group 4. She was referred to our department for a surgical treatment. We diagnosed suspected rectal carcinoma (Type 0-IIb, cTisN0M0) with radiation proctitis and performed a Hartmann operation. Pathological findings of the resected specimen showed a flat extension of highly differentiated adenocarcinoma in the mucosa and adenocarcinoma on the wall of the cyst extending from the submucosa to the muscularis propria. A diagnosis of radiation-induced advanced rectal carcinoma (Type 0-IIb, pT2N0M0, fStage I) with surrounding radiation injury was made. This case shows that care is needed to avoid a delay in treatment because the preoperative diagnosis of radiation-induced colorectal carcinoma is difficult.

We herein present a case of clinical complete response using nivolumab for anorectal malignant melanoma with lymph node recurrence. An 84 year-old male was referred to our hospital with a chief complaint of hematochezia and anal pain, which was finally diagnosed as anorectal malignant melanoma. Preoperative studies showed no distant metastases, and the patient underwent laparoscopic abdominoperineal resection. Although pathological exams revealed that the tumor had invaded the submucosa with multiple lymph node metastases, adjuvant chemotherapy was not used. Six months after surgery, a CT scan demonstrated right lateral lymph node swelling, which led to a diagnosis of recurrent malignant melanoma. Administration of nivolumab was started as treatment for the metastatic lesion. Although immune-related adverse events occurred, CT at 24 months after surgery showed that the recurrent tumor had disappeared, so the case was judged as a clinical complete response. In this report, we described a rare case of clinical complete response using nivolumab for recurrent anorectal malignant melanoma. Anorectal malignant melanoma is a rare disease with an extremely poor prognosis. This case suggests that nivolumab may provide a superior survival benefit.