2 37-year-old woman was transferred to our hospital with suspected biliary tract stones with acute ancreatitis and a periampullary tumor. She had been uffering from epigastric pain intermittently for the ast 3 years. No icteric sclera or abdominal mass was oted on physical examination. Blood chemistry reults all were within normal limits. The patient’s seum amylase level was 183 U/L and her lipase level as 238 U/L (normal range for both, 190 U/L). An bdominal computed tomography scan showed galltones, a soft-tissue nodule in the common bile duct CBD), and a juxtapapillary cystic lesion (Figure A). uodenoscopy revealed a bulge of the papilla of Vater esembling a submucosal tumor about 3 cm in size. An ndoscopic retrograde cholangiogram showed multile gallstones, CBD, and intrahepatic duct stones. In ddition, a contrast-filled cystic lesion about 4 cm in ize was noted in the papilla with multiple small filling efects within it (Figure B, arrow). A magnetic resoance cholangiogram showed the same findings. The atient underwent surgical intervention with a proviional diagnosis of large choledochocele of the diverticular ubtype. A cholecystectomy was performed first. After dentifying the CBD and pancreatic duct, a small orifice was ound near the ampulla of Vater and bile material was jected while palpating the cyst. Several yellowish stones ere noted within the cyst. Transduodenal resection of the yst and sphincteroplasty were performed. Histopathology howed the cystic space was lined partially by bile duct pithelium. The patient was symptom-free at the 2-year ollow-up evaluation. Choledochoceles or type III choledochal cysts are xtremely rare. Choledochoceles consist of cystic (type ) or diverticular (type B) dilatation of the terminal ntramural portion of the CBD protruding into the duoenum. Type B is less common and constitutes 21% of holedochoceles. The common clinical presentations of holedochoceles are intermittent upper-abdominal pain nd jaundice. Stones in the choledochocele or CBD may nduce acute pancreatitis and cholangitis.