A case of bile duct diverticulum with repeated acute cholangitis due to diverticular stone fall

A 34-year-old man presented to the emergency department with a chief complaint of epigastric pain. Endoscopic ultrasound detected a 5 mm stone in the common bile duct. After endoscopic sphincterotomy, the black stones and debris were removed with balloon catheter. Abdominal ultrasonography detected no gallbladder stones; hence, the patient was followed up. However, 3 months later, the patient again developed acute cholangitis caused by common bile duct stones and underwent endoscopic stone removal. Cholangiography under balloon occlusion revealed a left hepatic duct diverticulum with an internal defect. Intraductal ultrasonography showed a hyperechoic lesion with acoustic shadow in the diverticulum, suggesting a stone or debris. Therefore, the patient was considered to have had repeated acute cholangitis because of the presence of falling diverticular stones. The patient underwent left hemihepatectomy plus segmentectomy 1 and cholecystectomy. Histopathologically, it was a true diverticulum without internal epithelial atypia. Many debris were seen in the diverticulum. Gallbladder stones were not observed. Eventually, the patient was discharged from the hospital with no postoperative complications and no recurrence of cholangitis after 20 months.