Upper gastrointestinal tumors, including ampullary adenomas, occur frequently in patients with familial adenomatous polyposis (FAP). Guidelines recommend upper gastrointestinal endoscopy in FAP for surveillance of gastric and duodenal adenomas. However, adenomas can rarely arise from biliary epithelium in patients with FAP. Here, we describe a case of tubular adenoma at the hepatico-jejunal anastomosis with intraductal extension in a patient with FAP and previous pancreaticoduodenectomy. This report illustrates a unique case and emphasizes the need for data on postoperative surveillance in patients with FAP, particularly following pancreaticoduodenectomy.