Diagnostic Accuracy of Alpha-Methylacyl-CoA Racemase Immunohistochemical Expression for the Diagnosis of Ovarian and Endometrial Clear Cell Carcinomas

Background & Objective: Clear cell carcinoma (CCC) is an uncommon histopathologic subtype of ovarian and endometrial carcinoma. Due to the morphologic overlapping with other subtypes of ovarian and endometrial carcinomas, an accurate diagnosis is crucial.Methods: In this study, ۳۱ cases of ovarian clear cell carcinoma (OCCC), ۲۸ endometrial clear cell carcinoma (ECCC), and ۸۰ non-CCC subtypes (۳۳ high-grade serous carcinomas of the ovary, ۲ low-grade serous carcinomas, ۱۰ ovarian endometrioid, ۳ serous carcinomas and ۲۹ endometrioid carcinomas of the endometrium) were investigated for immunohistochemical expression of AMACR. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the distinction of OCCC and ECCC from other histopathologic subtypes were calculated.Results: Positive AMACR staining was seen in ۱۸ OCCCs (۵۸%) and ۱۰ ECCCs (۳۵.۷%). In the non-clear cell group, ۴۴ cases of ovarian (۹۸%) and ۲۵ cases of endometrial carcinoma (۷۸%) showed negative results. Only one case of ovarian endometrioid carcinoma and ۷ cases (۲۲%) of endometrial endometrioid carcinomas revealed a positive reaction (P<۰.۰۵). Collectively, sensitivity, specificity, PPV, and NPV of AMACR expression, for the diagnosis of OCCC were calculated as  ۵۸%, ۹۸%, ۹۴.۷%, and ۷۷.۲%, respectively. The sensitivity, specificity, PPV, and NPV were shown to be as  ۳۵.۷%, ۷۸.۱%, ۵۸.۸%, and ۵۸.۱%, respectively in the endometrium.Conclusion: AMACR may be  a highly specific immunohistochemical marker for the distinction of serous and clear cell carcinoma. A small percentage of endometrioid carcinoma may show positive staining. The sensitivity of this marker may not be higher than the other well-known Napsin-A IHC marker.

کلیدواژه ها:

Clear Cell Carcinoma ، Ovary ، Endometrium ، AMACR ، Immunohistochemistry ، accuracy