Duodenal adenomas are uncommon, however, when present a proportion have dysplasia associated with the adenoma and therefore require treatment. The options range from less invasive endoscopic treatments to a pancreaticoduodenectomy. This case report describes two patients with adenomas involving the ampulla of Vater. One patient had familial adenomatous polyposis, the other was a renal transplant patient with a large adenoma. Both patients’ adenomas contained high-grade dysplasia. Both patients underwent a pancreaticoduodenectomy. Histology of both specimens demonstrated that the adenoma had migrated up the bile duct for at least 7 mm, and the pancreatic duct for 8 mm in one patient. Limited resection of ampullary adenomas may leave residual adenomatous tissue in the bile duct with the risk of recurrent adenomatous disease and malignant transformation.