Smooth Muscle Cell anomalies associated with Gastric ECL Cell Carcinoid

The histologic and immunohistochemical study of ECL cell gastric carcinoids and of the extratumoral gastric mucosa revealed four variants of smooth muscle cell abnormalities:
 (1) hypertrophy of muscularis mucosae trapped within the tumors, a finding occurring in 76.5% of cases;
 (2) proliferation of stromal smooth muscle cells originating from the muscularas mucosae and mostly associated with tumor invasion of the submucosa (seen in 93.9% of cases with abundant stromal component of the tumors);
 (3) occurrence of frequent, prominent aggregates of smooth muscle cells in the lamina propria of the antral (but not of the fundic) mucosa of the stomach (found in 41.7% of cases);
 (4) increased thickness of the extratumoral muscularis mucosae in the fundic (but not in the antral) mucosa of patients with gastric carcinoids.

In addition, localized muscle cell proliferation can also be associated with foci of micronodular hyperplasia of endocrine cells in the extratumoral mucosa.

With the possible exception of the increased thickness of the extratumoral fundic muscularis mucosae, which may be influenced by the mucosal inflammatory process, it is suggested that the present findings represent a proliferative response of smooth muscle cells to basic fibroblastic growth factor whose production by gastric carcinoids and their precursor lesions has recently been demonstrated.

References

 Smooth Muscle Cell Abnormalities Associated with Gastric ECL Cell Carcinoids.Bordi C, Caruana P, D’Adda T, Azzoni C. Endocr Pathol. 1995 Summer;6(2):103-113. PMID: 12114646