CARCINOMA of the prostate is noted for its widespread metastases and has been reported to invade practically every organ and tissue of the body. However, it is unusual for carcinoma of the prostate, or any other type of cancer, to metastasize to the breast. Campbell and Cummins reviewed the literature and reported a case of cancer of the prostate simulating primary breast cancer. Their case was that of a 69-year-old man with prostatic cancer that developed metastasis to the breasts, skin, lymph nodes, liver, lungs, adrenals, epididymis, heart, and bones. The acid-phosphatase stains of the prostate and breasts were strongly positive. This paper reports of another case of metastatic cancer to the breast from the prostate. Report of a Case A 78-year-old man was admitted to Confederate Memorial Medical Center, on July 27, 1959, with the chief complaint of acute urinary retention and enlarged breasts. He gave a 5½-year history