Difficult preoperative diagnosis of pancreatic hamartoma

Abstract

We describe a patient with a pancreatic hamartoma. The patient is a 65-year-old woman followed for a hepatic cyst. She was asymptomatic, but a pancreatic tumor was incidentally found and she was referred for further evaluation. Serum tumor markers and hormone levels were within normal limits. Dynamic computed tomography scan showed a well-demarcated tumor in the head of the pancreas measuring 1.5cm in maximum diameter. An arterial phase image shows a relatively well-circumscribed nodule with enhancement in the portal venous phase. Endoscopic ultrasonography-fine needle aspiration was non-diagnostic. The patient underwent pylorus-preserving pancreatoduodenectomy with a preoperative diagnosis of a pancreatic neuroendocrine tumor. A well-demarcated solid nodule was found in the head of the pancreas. Microscopically, the lesion consisted of disarranged ductal and acinar cells embedded in fibroinflammatory stroma but lacked concentric elastic fibers in the duct walls, peripheral nerves, and islets of Langerhans. The histological diagnosis was pancreatic hamartoma. Pancreatic hamartoma is a rare tumor and it is very difficult to obtain a preoperative histological diagnosis. We report a patient with a pancreatic hamartoma resembling a non-functional pancreatic neuroendocrine tumor.