Epidermoid carcinoma of the breast.

Two patients with squamous cell carcinoma of the breast are described. In one patient the lesion represented a primary breast tumor; in the second, a metastases from primary bonchogenic carcinoma. Neither lesion possessed estrogen receptor protein. This report emphasizes the rarity of epidermoid lesions of the breast and the importance of identifying an extramammary primary source of metastases to the breast.