A nonfunctional neuroendocrine tumor of the pancreas - a case report.

Pancreatic neuroendocrine tumors (pNETs) represent about 1-5% of the pancreatic tumors, having an annual incidence of about 1/100 000, with difficult positive and differential diagnostic, especially in nonfunctioning tumors. We present a case of large dimensions (10/8 cm) pancreatic tail NET developed in a 65-year-old woman, incidentally discovered while she was examined for a strangled inguinal hernia. The patient had no specific tumor signs and the imagistic examination did not reveal any metastases. The histopathological and especially the immunohistochemical examinations were decisive for the diagnosis, treatment and prognostic establishment. The tumor showed intense positivity for chromogranin, synaptophysin, CD56, CD117, CK19, MNF-116 and negative for CK5/6 and CK7. The proliferative index established through the Ki-67 assessment was around 3%, while p53 was positive in 25-30% of tumor cells nuclei.