Heterotopic pancreatic tissue associated with type 1 choledochal cyst, cystolithiasis and gall bladder stones: a rare entity with review of literature.

Choledochal cyst is a rare congenital malformation, particularly when associated with stones in cyst (cystolithiasis), gallstones and heterotopic pancreatic tissue within the cyst wall. The current case represents a 5-year-old boy with abdominal pain, pale colored stools, and jaundice. Magnetic resonance cholangiopancreatography showed a cystic lesion, arising from common bile duct with cystolithiasis and cholelithiasis. He underwent excision of choledochal cyst and gallbladder with Roux-en-Y hepaticojejunostomy. Microscopic examination showed a cyst wall composed of fibrocollagenous tissue lined by cuboidal to low columnar epithelium. The subserosal layer of cyst wall showed presence of heterotopic exocrine pancreatic tissue comprising of pancreatic acinar cells and ducts. We report the first case of heterotopic pancreatic tissue associated with choledochal cyst and cystolithiasis and cholelithiasis occurring at the same time.