Secretory component and IgA in endometrial adenocarcinomas. An immunohistochemical study.

The localization of secretory component (SC) and IgA was immunohistochemically studied in 6 normal endometrium and 55 endometrial adenocarcinomas including 34 well, 11 moderately and 10 poorly differentiated ones. In normal endometrium, SC localization was found in the cytoplasm of epithelial cells and luminal contents of the gland. IgA showed similar localization of SC. Secretory phase endometrium contained proportionally larger numbers of positive cells for SC and IgA than proliferative phase endometrium. SC localization was found in all cases of well and moderately differentiated carcinomas, while it was found only in 4 cases out of 10 poorly differentiated carcinomas. IgA localization was similar to that of SC and this condition was thought to reveal the binding of IgA to SC existing in the tumor cells. The present immunohistochemical study revealed that the staining intensity of SC well correlated with the histological grade of differentiation of the tumors.