Squamous carcinoma of the breast.

Abstract

Twenty-four cases of carcinoma of the breast in which squamous differentiation was a prominent histologic feature are presented. The tumors were often relatively large and frequently formed large central cysts lined by squamous epithelium. Highly varied degrees of squamous differentiation were found in association with adenocarcinomas, anaplastic and medullary carcinomas, and one squamous carcinoma originating in a cystosarcoma phylloides. Two carcinomas were of an apparently pure squamous type. The five-year survival rate for 14 patients treated before 1965, 50%, is close to that achieved for all cases of carcinoma of the breast treated in the same period. It is concluded that although pure squamous carcinomas of the breast are rare, various degrees of squamous differentiation in association with other types of carcinoma of the breast are not infrequent, and that such differentiation has no apparent effect on clinical course or survival.