Primary papillary hyperplasia of the gallbladder and cystic and common bile ducts.

A unique case of primary papillary hyperplasia of the gallbladder and cystic and common bile ducts occurring in a young female without calculi, ulcerative colitis, or primary sclerosing cholangitis is reported. The papillary lesion involved the mucosa of the entire gallbladder and of the cystic and common bile ducts. Histologically, the gallbladder mucosal folds were close to one another and taller than normal. They were lined by normal-appearing columnar cells and pencil-like cells. The papillary projections of the common bile duct were lined only by columnar cells with prominent subnuclear vacuoles. No endocrine cells or cytologic atypia were noted. The differential diagnoses, including secondary hyperplasia, multiple adenomas, and papillomatosis of the gallbladder, are discussed.