Objective: To analyze the clinicopathological features of pancreatic neuroendocrine neoplasms (P-NENs).
Methods: From January 2006 to December 2010, 64 patients with P-NENs were diagnosed in the Department of Pathology, West China Hospital, Sichuan University. Immunohistochemical staining of neuroendocrine markers, synaptophysin (Syn) and chromogranin A (CgA), were first made to determine whether the tumor had neuroendocrine properties, then the P-NENs were classified as neuroendocrine tumor (NET), neuroendocrine carcinoma (NEC) and mixed adenoneuroendocrine carcinoma (MANEC, G3) according to the morphological changes and proliferative activity (Ki 67 expression).
Results: Of all the 64 cases detected, 60 were NETs and four were NEC. Most of the tumors were single solitary masses, and more than half of the tumors arose in the head of the pancreas, while about one third in the tail. The positive rates of CgA and Syn immunostaining were 96.9% and 95.3%, respectively. The tumor stages of the 64 patients were as follows: stage I, 44 cases; stage II, 11 cases; stage III, one case; and stage IV, 8 cases. The median age of patients in the study was 45.56 years. Of all the P-NENs, 38 cases were functional ones, presenting with characteristic clinical syndrome owing to hormone hypersecretion, while 26 cases were nonfunctional ones with no distinct clinical syndrome. 58 patients underwent surgical operation. The 5-year progression-free survival rate was 91.4%.
Conclusions: P-NENs may occur anywhere in the pancreas, and the clinical manifestations may not be easy to distinguish from other diseases. Diagnosis depends on pathological examination. Surgery is the major approach option, and the clinical prognosis is rather good. The tumor histological grade and distant metastasis are independent prognostic factors in P-NENs.