Neuroendocrine differentiation in human gastric carcinoma

Abstract

BACKGROUND Distinguishing between neuroendocrine carcinoma and adenocarcinoma may be difficult. METHODS In the current prospective study blood and tumor tissue from patients with gastric carcinoma were collected. The tissue was fixed in different ways to allow examination for neuroendocrine markers by multiple methods such as various histochemical and immunohistochemical methods and electron microscopy. Blood and tumor homogenates were examined by radioimmunoassay for specific hormones and general neuroendocrine markers. RESULTS Based on examination of general neuroendocrine markers such as chromogranin A (by immunohistochemistry, Northern blot analysis, and tissue concentration), neuron specific enolase (immunohistochemistry) as well as electron microscopy, it was possible to conclude that approximately 10% of the tumors were actually neuroendocrine malignant tumors. Among these tumors, the enterochromaffin-like (ECL) cell was the most preponderant cell of origin (Sevier-Munger positive and serotonin negative immunoreactive tumor cells with secretory granules resembling those observed in normal ECL-cells). As reported previously, tumors of the diffuse type (according to the classification of Laurén) most often were reclassified as neuroendocrine carcinomas. CONCLUSIONS The current study shows that neuroendocrine and particularly ECL cell-derived tumors are more common in the stomach than previously recognized. Cancer 1998;83:435-444. © 1998 American Cancer Society.