A rare case of retroperitoneal paraganglioma located in the neck of the pancreas: a case report and literature review.

Paraganglioma (PGL) is an uncommon tumor located in the head, neck and abdomen. The majority of the tumor is benign and the patient has no obvious clinical symptoms. However, PGL located in the pancreas is rather rare and tends to mimic Castleman's disease, pancreatic neuroendocrine tumors and pancreatic primary tumor. Herein, we reported a patient with PGL that occurred in the neck of the pancreas. A 75-year-old Chinese female presented to our hospital with a complaint of upper abdomen pain for two weeks and she had good past health. The laboratory findings and physical examination were all normal. Preoperative computed tomography (CT) and magnetic resonance imaging revealed a tumor located in the neck of the pancreas and a tentative diagnosis of Castleman's disease or PGL was made. We resected the tumor by laparoscopic surgery. Postoperative pathology and immunohistochemistry confirmed that the tumor was a PGL. The patient was recovered well after a postoperative follow-up of 6 months. PGL located in the neck of the pancreas is difficult to be diagnosed accurately and clinicians have difficulties in distinguishing PGL from Castleman's disease, pancreatic neuroendocrine tumors and pancreatic primary tumor. Fifteen cases were listed to show the characters of PGL located in the pancreas and we also presented the difference among PGL, Castleman's disease and pancreatic neuroendocrine tumor. We showed our experience of treating such a rare tumor hoping to help clinicians correctly diagnose and treat PGL.