WT1, estrogen receptor, and progesterone receptor as markers for breast or ovarian primary sites in metastatic adenocarcinoma to body fluids.

In tissue sections, detection of the Wilms tumor susceptibility gene 1 (WTI) protein, the hormonal receptors for estrogen (ER) and progesterone (PR), and gross cystic disease fluid protein (GCDFP) are useful for diagnosing ovarian and breast adenocarcinomas. We evaluated these markers for cytology cell-block preparations from 96 effusion specimens (metastases from 29 breast, 22 ovarian, and 45 adenocarcinomas from other sites). WTI protein was reactive in 19 cases inetastatic from ovary (86%), 2 from breast (7%), and none from other sites (specificity; 97%). Of the metastatic breast carcinomas, 21(72%) were reactive for ER, 15(52%) for PR, and 13 (45%) for both (combined specificity, 84%). GCDEP was reactive in only 4 breast cancer cases (14%). Ovarian tumors also were frequently positive for ER (19 [86%]), PR (II [SO%]), or both (10 [45%]). WTI protein is an effective marker for ovarian adenocarcinoma, especially in ascites. The detection of ER and PR in metastatic adenocarcinoma from pleural or pericardial efflusions can distinguish breast from lung primary sites. Reactivity for ER and PR did not distinguish between breast and ovarian metastases; however; studies for WTI protein and GCDFP may aid in making this distinction.