ARC'INORIA of the prostate most often begins between the agcs of 60
and 70, and has no recognized connection with senile enlargement or with prostatitis. Microscopically the growth is usually of scirrhous typc, but may also be an adenocarcsinoma with cubical or columnar cells.
I n thc common scirrhous form thc prostate is enlarged slightly or not a t all, but bccomes hard and nodular and the posterior median groove is lost. Thc gland hecomes fixed t o surrounding structures by infiltration. Owing to the freedom of their lymphatic rommunication the first extension of a careinoma of thc prostate is into the vcsiculz seminalcs, the lymph-glands, and the rellular tissue of the pelvis. I n the bladder the growth appear3 first in the form of submucous nodules which ulcerate later. Ulceration into the prostatic urethra is common in thc later stages. Posteriorly the growth spreads backwards in the pelvic. cellular tissue on either side of thc rectum arid may diminish its lumen. One or both ureters may become obstruckd. and nodules of growth may appear on thc peritoneum of the rrcto-vesical pouch.
I n adeno-carcinoma the prostate is enlargcd and nodular, but may bc soft enough to be mistaken for a non-malignant enlargement of the scnilc type.
Carcinoma of the prostate is apt t o cause skeletal metastases which arc of osteoplastic type. The new bone formed is usually spongy and abundant. 'isceral metastases are uncommon.
Sarcoma of the prostate is rare.