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.