Estrogen and progesterone receptors in primary eccrine carcinoma.

Primary eccrine carcinoma and metastatic mammary duct carcinoma are histologically similar and histogenetically related neoplasms that may on occasion be mistaken for one another. Mammary duct carcinomas, in primary or metastatic sites, will often express estrogen and progesterone receptors (ER and PR), and these may be detected by either biochemical or immunocytochemical methods. The expression of ER and PR in primary eccrine carcinoma, however, has not been studied. Three eccrine carcinomas were probed with antibodies to ER and PR. Immunoreactivity for hormone receptors was identified in all three cases. The recognition of this immunophenotype may be important in avoiding misdiagnosing receptor-positive eccrine carcinoma as metastatic breast cancer.