Immunohistochemical Expression of Neuron Specific Enolase-Positive Cells in Gastric Adenocarcinomas

ABSTRACT

In order to correlate the frequency of neuroendocrine cells with pathologic parameters in gastric adenocarcinomas, immunoperoxidase staining for neuron specific enolase was performed on 250 consecutive cases of surgically resected gastric adenocarcinomas(201 advanced gastric carcinomas[AGCs], 49 early gastric carcinomas[EGCs] and 2 cases of gastric carcinoid tumors. Of the 252 cases of gastric carcinomas, pure exocrine carcinomas were 174 cases(69%), pure neuroendocrine(NE) carcinomas 2 cases(0.8%), mixed exocrine and NE carcinomas 32 cases(12.7%), and exocrine carcinomas with occasional NE cells 44 cases(17.5%). The frequency of gastric carcinomas with NSE-positive cells increased with age proportionally. NSE positivity was higher in polypoid or fungating tumors(AGC Borrmann type I, II, EGC I and IIa) than ulcerative or scirrhous tumors. There was no significant difference in frequency of NSE-positive cells by histologic type and differentiation of gastric adenocarcinomas. The above findings reflect that most gastric carcinomas are heterogeneous in their constituents and suggest that both exocrine and neuroendocrine carcinomas are the expression of the extreme ends of the exocrine-endocrine differentiation spectrum based on the assumption that they develop from the pluripotent stem cells differentiating into both exocrine endocrine carcinomas.