ProExC is a novel marker for distinguishing between primary endometrial and endocervical adenocarcinomas

Abstract EN

Background : distinguishing end cervical adenocarcinoma (ECA) from endometrial adenocarcinoma (EMA) is clinically significant and cannot always be made on the basis of morphology alone or clinical findings.

The aim of this study was to study the potential utility of Pro ExC as a new marker for cervical adenocarcinoma, and to evaluate a panel of monoclonal antibodies composed of p16, ER, PR, and vimentin, and assess their diagnostic value in distinguishing between ECA and EMA.

Methods : immunohistochemistry using monoclonal antibodies to Pro ExC, p16, estrogen receptor (ER), progesterone receptor (PR), and vimentin, was performed to examine 30 cases, including 10 ECAs and 20 EMAs.

Results : Eight out of 10 cases (80 %) of ECA were positive for Pro ExC, whereas only 2 cases of EMA (10 %) were positive.

The difference of Pro ExC expression in the two groups of malignancy was statistically significant (p = 0.003).

P16 was positive in 8 cases (80 %) of ECAs and in 4 cases 20 % of EMAs.

Estrogen receptor was negative in all cases of ECA, while it was positive in 95 % of EMA.

Progesterone receptor was positive in 2 cases (20 %) of ECA and in 16 cases (80 %) of EMA.

Vimentin was positive in only one case (10 %) of ECA, and in 16 cases (80 %) of EMA.

Conclusion : Pro ExC is a novel immunohistochemical marker for differentiating ECA from EMA and its inclusion in a panel of immunohistochemical markers including p16, ER, PR, and vimentin is recommended when there is morphological and clinical doubt as to the primary site of end cervical or endometrial origin.