Signet-ring-cell carcinoma of the ampulla of Vater: a case report.

We encountered a rare variant of carcinoma of the ampulla of Vater in a 68-year-old man with postprandial abdominal pain and nausea. Ultrasonography and computed tomography showed a dilated common bile duct and main pancreatic duct. At duodenoscopy, the papilla of Vater was enlarged, and biopsy specimens taken from the papilla revealed signet-ring-cell carcinoma. Endoscopic ultrasonography showed a hypoechoic tumor without pancreatic invasion. Pylorus-preserving pancreatoduodenectomy was performed. Histologic examination of resected specimens indicated lymphatic and vascular invasion, but surgical margins were tumor-free. The patient is alive and disease-free 10 months after the operation.