Pure squamous carcinoma of the breast. Report of a case diagnosed by aspiration cytology.

A case of pure squamous carcinoma of the breast diagnosed by needle aspiration cytology is presented. The three conditions required for that diagnosis were fulfilled: (1) an absence of elements other than malignant epidermoid cells, (2) the independence of the lesion from adjacent dermal structures, and (3) the exclusion of other squamous carcinomas in the patient. Other well-documented cases of this entity are reviewed.