Minute carcinoid tumor of the uterine cervix associated with microinvasive adenocarcinoma, with reference to its histogenesis.

A rare case of carcinoid tumor of the uterine cervix associated with adenocarcinoma was reported. The carcinoid tumor was composed of round to polygonal cells showing solid or trabecular proliferation. Most of these cells and a small number of isolated cells wedged in neoplastic glands were positive with either Grimelius or Fontana-Masson stains, and also positive for serotonin by immunostain (PAP method). Positively stained cells were thus considered to have the same histochemical nature as enterochromaffin cell. The carcinoid tumor was minute, about 2 X 2 mm and the adenocarcinoma was a microinvasive one. In some parts, smooth transition between both tumor components was observed. From these findings, it is suggested that both the carcinoid tumor and the adenocarcinoma in the present case were derived from a primitive precursor cell of common mesodermal origin.