Carcinoma invasivo mioblastomatoide (histiocitoide). Presentación de 2 casos y revisión de la literatura Myoblastomatoid invasive carcinoma (histiocytoid). Report of two cases and review of the literature

SUMMARY Histiocytoid carcinoma of the breast is a rare variant of breast cancer, discussed as different subtype from other breast lesions, being a frequent diagnostic problem due to its hystologic similarity with other types of breast cancer, and because of the few number of cases in literature. Histiocytoid carcinoma is considered by some authors as a subtype of lobular infiltrating carcinoma, easily confused with benign conditions or other mammary lesions composed of cells with a pink granular to foamy cytoplasm and eccentric nucleus. We have reviewed 925 cases from our hospital files since 1996, in order to study the incidence in our area, finding 7 cases diagnosed as histiocytoid carcinoma, 5 of them have been re-classified as pleomorphic lobular carcinoma with apocrine changes, and only two cases were classified as histiocytoid carcinoma upon histological, cytological and immunochemical criteria.