NEUROENDOCRINE DIFFERENTIATION IN HUMAN GASTRIC-CARCINOMA

BACKGROUND, Distinguishing between neuroendocrine carcinoma and adenoc arcinoma map be difficult. METHODS, In the current prospective study b lood and tumor tissue from patients with gastric carcinoma ware collec ted. The tissue was fixed in different ways to allow examination for n euroendocrine markers by multiple methods such as various histochemica l and immunohistochemical methods and electron microscopy. Blood and t umor homogenates were examined by radioimmunoassay for specific hormon es and general neuroendocrine markers. RESULTS. Based on examination o f general neuroendocrine markers such as chromogranin A (by immunohist ochemistry, 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 wer e actually neuroendocrine malignant tumors. Among these tumors, the en terochromaffin-like (ECL) cell was the most preponderant cell of origi n (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 Lauren) most often were reclassified as neuro endocrine carcinomas. CONCLUSIONS, The current study shows that neuroe ndocrine and particularly ECL cell-derived tumors are more common in t he stomach than previously recognized. Cancer 1998;83:435-44. (C) 1998 American Cancer Society.