An unusual case of extramammary Paget's disease. Paget's disease of the glans penis probably originating from a prostatic duct carcinoma (transitional cell carcinoma of the prostate).

A patient, having been treated by total cystectomy and Bricker's conduit operation for prostatic duct carcinoma with intraepithelial extension into the prostatic urethra and bladder, developed an annular, psoriasiform eruption around the external orifice of the urethra two and one-half years later. A biopsy of this lesion showed pagetoid changes of the epidermis. Microscopic examination of the surgical specimen, consisting of the glans penis and corpus spongiosum, demonstrated intraepithelial-tumor permeation into the glans penis, penile urethra, and periurethral glands (Littre). It seems reasonable to conclude that this is an unusual case of Paget's disease of the glans penis which probably originated from a prostatic duct carcinoma.