Malignant change in a duodenal adenoma in familial adenomatous polyposis: report of a case.

Patients with FAP (familial adenomatous polyposis) are known to be at high risk for duodenal cancer. Although the adenoma-carcinoma sequence is thought to exist in the duodenum, clinical observation of the development of duodenal adenoma to cancer has rarely been reported. We outline a 44-yr-old postcolectomy man with FAP who underwent regular gastroduodenoscopy annually or biannually and was found to be harboring duodenal ampullary cancer 5 yr after colectomy. Endoscopic and pathological examination of the ampullary lesion during these 5 yr revealed progression of pathology from adenoma to carcinoma. Pathology of the surgical specimen confirmed ampullary cancer. This in vivo demonstration of the adenoma-carcinoma sequence highlights the current limitations of duodenal surveillance in FAP.