Periampullary adenomyoma: report of two cases.

Adenomyoma is a rare nonneoplastic lesion of the biliary tract. We report two cases of adenomyoma; one located in the duodenum, and the other located in the ampulla Vateri. Both patients presented with jaundice, and preoperative endoscopic and radiologic procedures could not show whether the tumor was benign or malignant. Despite intraoperative frozen section in one patient, the diagnosis of adenomyoma was not confirmed until after pancreaticoduodenectomy.