Serotonin expression in gastric neuroendocrine tumors and in foci of endocrine cell hyperplasia

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Introduction: The most abundant neuroendocrine (NE) cell population of the human oxyntic mucosa is the enterochromaffin-like (ECL) cells, followed by ghrelin, somatostatin and serotonin cells, respectively. All types of ECL cell carcinoids (ECL-CCs) contain serotonin cells but in a varying frequency. Hitherto, only foci of ECL and ghrelin cell hyperplasia have been described in the peritumorous mucosa of types I and II ECL-CCs. It is established that hypergastrinaemia can cause ECL cell hyperplasia but it does not affect serotonin cells. The vesicular monoamine transporter 2 (VMAT 2) is used as an immunohistochemical marker for ECL cells.

Aim(s): To elucidate the incidence and distribution pattern of serotonin immunoreactive (IR) cells in various types of human gastric NE tumors (GNETs), and in their surrounding mucosa in relation to VMAT 2.

Materials and methods: Altogether 58 GNETs [types I (n=33), II (n=3), III (n=9) ECL-CCs, ghrelinomas (n=2) and poorly differentiated NE carcinomas (n=11)], as well as their adjacent tumor free mucosa, were included. Consecutive sections were immunohistochemically analyzed.

Conference: 7th Annual ENETSConcerence (2010)

Presenting Author: Tsolakis A

Authors: Tsolakis A, Falkmer S, Grimelius L,

Keywords: enterochromaffin-cell carcinoids, immunohistochemistry, serotonin cell hyperplasia, VMAT 2,