Primary pancreatic paraganglioma: a report of two cases and literature review.

Paraganglioma is a rare tumor of paraganglia, derived from neural crest cells in sympathetic or parasympathetic ganglions. Primary paraganglioma originating from the pancreas is rare. We report two patients with paraganglioma in the head of the pancreas, in whom computed tomography showed a sharply marginated, hypervascular tumor with cystic areas. Significant intratumoral vessels and early contrast filling of the draining veins from the mass were not found. Although the pancreatic paraganglioma was located at the pancreatic head, the bile ducts often revealed no dilation, and sometimes the main pancreatic duct was mildly dilated. These findings are helpful in differentiating pancreatic paraganglioma from other pancreatic neoplasms. It is often difficult to distinguish between nonfunctional pancreatic paragangliomas and pancreatic endocrine tumors. In many reports,pancreatic paragangliomas show the retroperitoneal extension of a paraganglioma into the pancreas rather than a true pancreatic neoplasm. In surgical treatment, we could select simple excision of the tumor rather than radical surgery.