Histopathological diagnostics of gynecological
malignancies continues to be challenging despite the well established criteria. For example, the morphological distinction of uterine
leiomyosarcoma from certain variants of benign
leiomyoma can be difficult. Herein, we investigated the expression of
Carbonic anhydrase (CA) II, IX, and XII in the normal endometrium,
leiomyomas, uterine
sarcomas, and endometrial
adenocarcinomas using immunohistochemistry. These
isozymes are considered promising diagnostic markers and therapeutic targets. The normal endometrium showed high CA XII expression, whereas the signals were lower in endometrial
adenocarcinoma (p < 0.004). Only sporadic CA IX staining was found in the normal endometrium, whereas the
enzyme was overexpressed in most cases of endometrial
adenocarcinoma (p < 0.005). CA II expression was slightly weaker in the normal endometrium than that in the
adenocarcinomas (p < 0.008). Positive immunostaining reactions for CAs were observed in the uterine
sarcomas, whereas all
leiomyomas were negative for CA II and XII. A comparison between
leiomyomas and
sarcomas showed statistically significant differences for all studied
isozymes (p < 0.001). Our study shows that CA
isozymes could together serve as histopathological
biomarkers for differential diagnosis between uterine
leiomyosarcoma and
leiomyoma. In addition to being found in
leiomyosarcomas, CA II and IX were overexpressed in endometrial
adenocarcinoma, where they might regulate the pH of the tumor microenvironment.