Expression of cytokeratins in granulosa cell tumors and ovarian carcinomas

One of the problems in histopathology of ovarian tumors is differential diagnosis between the poorly differentiated carcinomas and granulosa cell tumors of the sarcomatoid type. Hence we evaluated the expression of various cytokeratins (CK 1-19; CK 10, 13, 14, 15, 19; CK 8, 18, 19; CK HMW 1, 5, 10, 11; CK 8; CK 1-19 Stähli; CK AE1/AE3) immunohistochemically in 53 ovarian malignancies (11 of them poorly differentiated carcinomas and 12 granulosa cell tumors). CK HMW was not detected in granulosa cell tumors, and in only half of the carcinomas. AE1/AE3 was expressed by more than 90% of ovarian carcinomas but by one granulosa cell tumor only. The other keratins we investigated showed higher expression rates in granulosa cell tumors and/or lower expression rates in ovarian carcinomas. We think that cytokeratin immunohistochemistry is of value in differentiating between granulosa cell tumors and ovarian carcinomas.