Melanotic schwannoma of the pancreas: report of a case.

We report a case of pancreatic melanotic schwannoma mimicking an epithelial cystic neoplasm of the pancreas. A 67-year-old Japanese woman underwent routine ultrasonography, which showed a large cystic mass in the head of the pancreas. Contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) showed an inhomogeneous, round cystic mass, which was encapsulated, in the head of the pancreas. We performed pyrolus-preserving pancreatoduodenectomy under the tentative diagnosis of a cystic neoplasm of the pancreas. The histopathologic diagnosis was benign melanotic schwannoma. The patient is now well after 43 months of follow-up. We describe the CT and MRI findings in detail, and review the literature on previously reported cases of pancreatic schwannoma.