PRIMARY SQUAMOUS-CELL CARCINOMA OF FEMALE MAMMARY-GLAND

Squamous metaplasia can be demonstrated in about 4% of all invasive ca rcinomas of the breast. Primary squamous cell carcinomas of the breast are rare, since they occur in less than 1% of all primary invasive br east carcinomas. In order to classify a breast tumor as a primary squa mous cell carcinoma one must exclude an epidermal origin, especially f rom the nipple region and the possibility of metastatic infiltration o f the the breast by a squamous cell carcnoma from a different location . Causative and formal pathogenesis of primary squamous cell carcinoma of the breast is not clear. A pluripotent embryonal stem cell origin is discussed, considering the phylogenetic descent of the mammary glan d from skin appendages. Squamous metaplasia is also suggested to be a precursor of squamous cell carcinoma. Here endocrine stimulation and c hronic inflammation may both play an inductive role. The number of pub lished cases of squamous cell carcinomas developing years and decades after implantation of silicon prostheses has increased in recent years . These rumors probably develop on top of squamous metaplasia induced by the inflammatory pseudocapsule. Estimating the prognosis and therap eutic management in patients with squamous cell carcinoma of the breas t should follow the same guidelines as for other squamous cell cancers .