Progression of a benign epithelial ampullary tumor to adenocarcinoma.

Benign tumors of the extrahepatic biliary ducts are rare. The high recurrence rate following local resection of these benign tumors is well known, but the development of one into a malignant tumor has received little attention. The recurrence 4 years after local excision of a benign periampullary tumor that developed into a well-differentiated papillar adenocarcinoma is described in this case report. Radical resection was performed by means of a pancreatoduodenectomy. The literature concerning the progression of benign extrahepatic tumors to adenocarcinomas is reviewed.