Primitive neuroectodermal tumor of the pancreas. A case report of an extremely rare tumor.

Primitive neuroectodermal tumor (PNET) of the pancreas is extremely rare. Although the diagnosis of PNET is suggested by the light microscopic appearance of the tumor, it should be confirmed by the immunohistochemical evaluation of the c-myc expression and if possible, further determination of the particular chromosome translocation, t(11;22)(q24,q12). In this report, we present a male patient with pancreatic PPNET who had been followed up for 50 months. The related literature is also reviewed. In our case, the pathologic diagnosis was based on the positive immunoreactivity for CD99 in many of the tumor cells. The complementary cytogenetic studies were not possible in the private setting of the patient's treatment. The patient was 31 years old when first operated. Within 4 months of the first operation he had local recurrence. In the third year of his follow-up he had been discovered to have pulmonary metastases and another metastatic tumor in his lung was diagnosed the year after. The metastatic foci were primarily treated by surgical resections. He had chemotherapy after each resection of pulmonary metastatic foci. After 50 months of the initial surgical intervention, he succumbed to widespread thoracic and bone metastases. Because of the extreme rarity of PPNET in the pancreas, and its rather protracted course, we think our case may further contribute to the ever expanding database for this particular entity.