A 75-year-old woman was referred to our hospital with a primary complaint of dysphagia and was diagnosed with esophageal achalasia. She suffered from perforation of the esophagus after balloon dilatation; however, she was discharged after the symptoms improved. After 1 year and 6 months, she returned to our hospital following a flare-up of symptoms. CT and oral contrast examination revealed a dilated S-shaped deformed esophagus with a maximum diameter of 7.5 cm. Because esophageal perforation occurred during the initial dilatation, further dilatation could not be performed, and there was a high risk of perforation during myotomy or peroral endoscopic myotomy; therefore, an esophagectomy was performed. As the patient had malnutrition and low cardiopulmonary function, one-stage esophagectomy and reconstruction had a high risk of perioperative complications, and hence a two-stage divided surgery was used. The patient had a good postoperative course and was discharged on the 31st postoperative day. Following discharge, her food intake increased, and at 1 month after discharge, she was able to consume approximately 1,300–1,400 kcal/day orally. An esophagectomy is highly invasive and is rarely performed for patients with esophageal achalasia, but our case suggests that it should be considered depending on the examination findings and treatment course.

A 64-year-old male visited a clinic due to left lower quadrant abdominal pain for 2 days. He was referred to our hospital for retroperitoneal emphysema observed on abdominal CT. Blood tests showed severe inflammation. Contrast-enhanced CT of the abdomen showed increased density of the adipose tissue and pneumoperitoneum around the celiac and superior mesenteric arteries. Peritonitis was localized, and conservative treatment was initiated. A nasal decompression tube was inserted under fluoroscopic guidance, and the tip was guided to the end of the descending duodenum. The tube was placed for intermittent continuous suction and the patient was treated with total parenteral nutrition, proton pump inhibitors, pancreatic enzyme inhibitors, and antibiotics. Inflammation gradually improved and the patient started oral intake on treatment day 17. On treatment day 29, upper gastrointestinal endoscopy was performed, and a diverticulum with granulation tissue was observed in the transverse duodenum. Diverticular perforation of the transverse duodenum is rare, and there are very few reports of cases with conservative treatment. Our case shows that conservative management of this condition is feasible with careful observation.

We report a case of follicular lymphoma of the extrahepatic bile duct. A 70-year-old man was taken to a local hospital for epigastric pain, jaundice, and an itching sensation, and was diagnosed with extrahepatic cholangiocarcinoma. Pylorus-preserving pancreaticoduodenectomy was performed at our hospital, and a histopathological examination showed follicular lymphoma of the extrahepatic bile duct. He was treated with adjuvant chemotherapy. Seven years after surgery, recurrence of lymphoma was diagnosed and was again treated with chemotherapy. The patient is alive without recurrence at 14 years after surgery. Follicular lymphoma of the extrahepatic bile duct is extremely rare, with only 9 cases reported in the literature. Malignant lymphoma of the extrahepatic bile duct is difficult to diagnose preoperatively, and is mostly diagnosed incorrectly as cholangiocarcinoma or pancreatic head carcinoma. However, treatment and prognosis of malignant lymphoma differ from these diseases, which makes it important to obtain a correct diagnosis using a preoperative examination, especially by biopsy.

A 60-year-old man was referred to our hospital due to a protruded lesion of the gallbladder detected in a medical checkup. Endoscopic US showed diffuse small protruded lesions in the gallbladder. MRCP showed an anatomical anomaly in which the cystic duct formed a common trunk with the posterior segmental branch that ran into the common bile duct alone. No pancreatobiliary maljunction was observed. The possibility of a latent malignancy could not be ruled out, and laparoscopic cholecystectomy was performed. Intraoperative cholangiography was conducted from the cystic duct for early detection of possible misidentification of the bile duct. The cystic duct and posterior segment branch were visualized, and contrast medium also flowed into the pancreatic duct. The amylase concentration of the bile in the gallbladder was 43,875 U/l and the lipase concentration was 12,450 U/l. On the day after surgery, postoperative back pain appeared, and laboratory data showed increased serum amylase and C-reactive protein. Swelling of the pancreas and surrounding fat opacity were detected on CT, and acute pancreatitis was diagnosed. The patient recovered with conservative treatment. Pathological examination revealed hyperplastic change in the mucosa of the gallbladder without malignant findings. This case shows that visualization of the pancreatic duct by cholangiography during laparoscopic cholecystectomy may be a cause of development of pancreatitis.

A 44-year-old woman with a chief complaint of pain due to bruising in the upper abdomen visited her local doctor. Intra-abdominal bleeding and intestinal injury were suspected, and she was referred to our hospital. Based on CT findings, acute generalized peritonitis due to pancreatic injury or ruptured pancreatic cyst was suspected, and emergency surgery was performed. The histopathological findings of the partially resected cyst wall revealed a mucinous cystic neoplasm. Eleven days after the initial surgery, pancreaticoduodenectomy was performed. Mucinous cystadenocarcinoma (MCC) was diagnosed from the resected specimen. There is no evidence for a benefit of chemotherapy after radical surgery for ruptured MCC. In our case, S-1 therapy was selected and the patient has been recurrence-free in a short period of observation.

Four years have passed since the first outbreak of the Coronavirus Disease 2019 (COVID-19) pandemic, but no consensus has been reached regarding its relationship with ulcerative colitis (UC). We experienced a case of UC that worsened after the patient contracted COVID-19 and required emergency surgery. The patient was a 62-year-old man who was undergoing drug treatment for UC. Symptoms such as bloody stool and abdominal pain worsened after onset of COVID-19. The dose of immunosuppressants was increased, but there was no improvement in symptoms and renal function worsened. It was determined that drug treatment had reached its limit, and 29 days after onset of symptoms, laparoscopic subtotal colectomy and ileostomy were performed. Pathological findings of the resected specimen revealed acute inflammation due to UC. Various mechanisms of organ damage caused by COVID-19 have been proposed, including direct damage by the virus and indirect damage mediated by an immune response. In such cases, early surgery should be considered when drug treatment becomes difficult.