KERATIN-7 AND KERATIN-20 AS DIAGNOSTIC MARKERS OF CARCINOMAS METASTATIC TO THE OVARY

The most common carcinomas metastatic to the ovary that mimic ovarian primaries are colonic adenocarcinomas and endometrial carcinomas. Conv entional histochemical staining procedures, even in combination with a dditional immunohistochemical assays, are of limited value in distingu ishing between these metastases and primary ovarian carcinomas. in thi s study we investigated whether the application of monoclonal antibodi es against keratins 7, 8, and 20 could help in differentiating between these categories. The reactivity patterns of 40 carcinomas metastatic to the ovary were compared with those of their primary carcinomas on the one hand and with various primary ovarian carcinomas and mesotheli omas on the other. Colon cancer metastatic to the ovary was keratin 7 negative and keratin 20 positive in 94% of the cases; in contrast, all primary ovarian carcinomas were keratin 7 positive and keratin 20 neg ative, with the exception of two cases of mucinous cystadenocarcinoma. Ovarian metastases of gastric cancer usually contained keratins 7 and 20. Metastases of endometrial cancer to the ovary and primary ovarian carcinomas usually showed similar keratin expression. We propose that keratin 7 and 20 antibodies may be of help to distinguish between pri mary ovarian carcinomas and carcinoma metastases in the ovary. Copyrig ht (C) 1995 by W.B. Saunders Company.