Villous adenomas of the duodenum and an unusual variant.

We report two cases of villous adenoma of the duodenum, one arising from the main papilla and the other from the accessory papilla. Both were managed by local resection. In one case endoscopic biopsies and intraoperative frozen sections were negative for carcinoma but histology of the locally resected specimen revealed a focus of invasive adenocarcinoma. Villous adenomas of the duodenum have a high risk of malignant change and foci of carcinoma can be missed on endoscopic biopsy. The literature is reviewed and the clinical, diagnostic, pathological and therapeutic aspects of villous adenomas of the duodenum are discussed.