Primitive neuroectodermal tumor of the pancreas.

The primitive neuroectodermal tumor (PNET) of the pancreas, a member of Ewing's sarcoma family of tumors, is extremely rare. We treated a 37-year-old Japanese man who had a solitary pancreatic tumor 40 mm in diameter and multiple hepatic tumors with surgical resection. The PNET was positive for CD99 on immunohistochemical staining. Fluorescence in situ hybridization (FISH) was also performed, which revealed a Ewing sarcoma breakpoint region 1 (EWSR1) 22q12 rearrangement. According to the Japan-Ewing protocol, chemotherapy with Ifomide (ifosfamide), etoposide, vincristine, and cyclophosphamide was given after surgery. To the best of our knowledge, to date 13 PNET cases have been reported with a mean age for all patients of 19.3 years old. Surgical resection was performed in most cases and some patients received postoperative chemotherapy. The clinicopathologic characteristics and management of this extremely rare disease are also discussed.