Carcinoid tumor of the Vater's papilla presenting with chronic pancreatitis--a case report--.

Carcinoid tumors are common in the duodenum except for in the Vater's papilla [1-9]. We report here a case of carcinoid tumor arising in the Vater's papilla with repeated episods of pancreatitis. The patient is a 28 year-old-woman who had repeated abdominal pain with elevated serum amylase and had been treated as chronic pancreatitis. Computed tomography (CT) revealed a slight dilatation of the main pancreatic duct from the pancreatic head to the tail, and mild swelling of the pancreas. A submucosal tumor measuring 1.3 cm in diameter was detected in the ampulla of Vater by esophagogastroduodenscopy (EGD), and total papillectomy was performed under the suspicious of carcinoid tumor. The tumor was not encapsulated, 1.0 cm in diameter, undefined, and whitish in color. Histologically monomorphic tumor cells with lightly eosinophlic cytoplasm and round nuclei proliferate in trabecular and solid patterns. Immunohistochemically tumor cells were positive for neuron-specific enolase, chromogranin A and synaptophysin, and the tumor was diagnosed as carcinoid tumor. It should be noted that carcinoid tumor in the ampulla may occur with initial signs of acute or chronic pancreatitis.