Gastric carcinoids: Review a propos of two cases

Abstract

SUMMARY
Gastric carcinoids are neoplasms originating from the
endocrine cells of the gastric wall and represent less than
1% of all gastric tumours. Their frequency appears to be
rising in parallel with the increasing use of upper
gastrointestinal endoscopy and the development of
techniques for specific immunohistochemical study of
gastric biopsies. The pathophysiological classification of
gastric carcinoids into three types is clinically useful. The
majority (75-80%) belong to Type I, which is associated with
chronic atrophic gastritis type A. They develop as a response
to chronic hypergastrinaemia, causing sequentially hyperplasia,
dysplasia and neoplasia of the ECL (enterochromaffin-
like) cells. They follow a benign clinical course and
only exceptionally metastasize. Type II carcinoids (5-13%)
are also associated with hypergastrinaemia and develop in
patients with the Zollinger-Ellison syndrome as part of
multiple endocrine neoplasia type 1 (MEN1). They have a
slightly higher malignant potential than type I carcinoids.
Type III includes the sporadic gastric carcinoids (14-25%)
which are invasive tumours with metastases often present
at the time of diagnosis. They are not associated with hypergastrinaemia
and require more aggressive surgical treatment
than types I and II. We review the current management
approaches and report two cases of gastric carcinoids, one
demonstrating that classification of these tumours is not
always straightforward and the other highlighting the
importance of extensive endoscopic sampling in the setting
of multiple gastric polypoid lesions. Key words: carcinoid, neuroendocrine tumour, gastric
tumour, gastric polyp, atrophic gastritis, enterochromaffinlike
cells, gastrin, gastrinoma