Pancreatic neuroendocrine neoplasms: a clinicopathological analysis of 72 cases

Abstract

Objective To explore the clinicopathological characteristics of pancreatic neuroendocrine neoplasms (P-NENs) and the prognosis. Methods The clinicopathological data of 72 patients with P-NENs in Sun Yat-Sen Memorial Hospital from December 2011 to September 2017 were analyzed retrospectively, and the gender, age, tumor size, local infiltration, neural invasion and distant metastasis were collected. According to the diagnostic criteria of P-NENs (Chinese edition 2013), tumor classification was determined by histological mitotic figure count and cell proliferation index (Ki67) proliferation activity. Expressions of Syn, CgA, NSE and CD56 were determined by immunohistochemical staining. Results Seventy-two patients with P-NENs were enrolled, including 33.3% male(n=24) and 66.6% female (n=48), and the median age was 56 years old (range: 12-76). 24 patients (33.3%) were NET G1, 44 patients (61.1%) were NET G2 and 4 patients (5.6%) were NET G3. The mean size of tumor was 38.2±19.2 cm3 ( range: 0.1-371 cm3). Immunohistochemistry staining positive rates for Syn, CgA, NSE and CD56 were 98.6%, 95.8%, 88.9% and 90.3% respectively. Tumor classification was correlated with tumor size, local infiltration, perineural infiltration and distant (liver) metastasis (all P<0.05). There was no statistically significant differences on positive rate of Syn, CgA, NSE and CD56 among G1, G2 and G3. Conclusions Tumor classification, size, local invasion, perineural infiltration and distant (liver) metastasis were all important clinicopathological features and prognostic factors of P-NENs. Syn, CgA and Ki67 were essential immunohistochemical markers to diagnose P-NENs. Key words: Pancreatic neoplasms; Neuroendocrine tumors; Immunohistochemistry; Prognosis