Experimental gastrocystoplasty in rats: risk of developing ECLoma.

Objective: There are no clinical reports on the risk of carcinoids in the gastric segment following gastrocystoplasty. The aim of the present study was to examine whether gastric carcinoids could develop in a rat model of gastrocystoplasty.

Materials And Methods: Rats were subjected to gastrocystoplasty in which 10% of the oxyntic part of the stomach was removed (i.e. 10% fundectomy), gastrocystoplasty with 90% fundectomy (known to induce hypergastrinemia), sham operation, or no operation, and were followed up for 6 months. Tissue specimens of bladder and stomach were analyzed by means of pathology and immunohistochemistry.

Results: Atrophy of gastric glands in the augmented bladders was found after gastrocystoplasty with either 10% or 90% fundectomy. Gastrocystoplasty with 90% fundectomy resulted in hyperplasia of the oxyntic mucosa, enterochromaffin-like (ECL) cell hyperplasia and ECLoma in the remnant stomach, and atrophy of the oxyntic mucosa and ECLoma in the gastric segment of the bladder.

Conclusions: ECLoma could develop in the gastric segment of the bladder after gastrocystoplasty, particularly in the setting of hypergastrinemia. The tumorigenesis of ECLoma seems to follow the same pathological pathway regardless of whether the oxyntic mucosa is located in the stomach or the bladder.