Atrophy of the prostate is common in old age, the gland becoming smaller through degeneration of the epithelium with contraction of the fibrous tissue.

Fig. 174. - Hypertrophy of the Middle Lobe of the Prostate (White and Wood).

A, Middle lobe of prostate; B, urethra.

Hypertrophy also frequently occurs in old men. The entire gland or any one of its lobes may increase in size. Although the gland is composed of two lobes connected by a narrow isthmus the hypertrophy can involve the isthmus alone and cause a great increase in size. The median enlargement is the most important, as it is the one in which there are severe clinical symptoms. By the hypertrophy of this portion the opening to the urethra is obstructed and retention of urine occurs. This may at first merely give rise to increase in the thickness of the muscle-fibers and dilatation of the bladder. Subsequently infection takes place, the urine decomposes, and the bladder is no longer able to expel the urine. Pyelitis and pyelonephritis may follow.

Fig. 175. - Hypertrophy of the Prostate Gland (McFarland).

Microscopically the enlargement is due either to a glandular increase or to a hyperplasia of the fibrous connective-tissue stroma and the muscle. In the latter case there may be more or less widespread atrophy of the tubules. In the glandular form the appearance closely simulates that of an adenoma.

The enlargement may result from a chronic posterior urethritis or a long-continued congestion.

Prostatitis, inflammation of the prostate, is nearly always secondary to a gonorrheal posterior urethritis, but may follow injury to the perineum. In the acute infectious form there is a desquamation of the glandular epithelium, with collections of pus in the acini, and a round-cell infiltration of the interstitial tissue. There may be numerous foci of suppuration scattered throughout the tissue. Large abscesses may form and these generally evacuate into the urethra. If further infection of the surrounding tissues does not occur cicatrization and recovery take place.

With the opening into the urethra there may be an extravasation of urine with phlegmonous inflammation of the pelvic tissues.

If the abscesses do not rupture, they may be absorbed or become inspissated, encapsulated, and calcified.

Concretions are quite frequently found in the prostatic alveoli in old men. They are generally numerous and vary in size from the microscopic to those large enough to be seen with the naked eye. They are round, translucent, colorless bodies that show a distinct concentric arrangement. The older ones are of a slight brownish tinge. They are frequently spoken of as corpora amylacea on account of their so often giving a starch reaction, coloring blue or a mahogany-brown color with iodin. They may, however, not stain at all. As they become larger, lime-salts are commonly deposited around them. Occasionally the concretions may be so large as to cause the ducts to dilate. At times they escape into the urethra and are passed out with the urine.

Tuberculosis of the prostate is generally secondary to tuberculosis of the other genito-urinary structures, particularly of the vas deferens and epididymis. Throughout the gland there are caseous masses varying in size. These may become encapsulated and calcified or may rupture into neighboring tissues. Primary tuberculosis sometimes occurs as a hematogenic infection, but is quite rare.

Tumors of the prostate are not common. Sarcoma and adenoma are very rare. Carcinoma is more frequent, but even it is unusual either as a primary or a secondary growth. It may occur in rather young individuals and appears as a nodular yellowish mass that projects into the bladder and urethra. It soon breaks down, leaving an ulcerated surface. Extension usually involves the bladder and rectum, but metastases to the inguinal nodes or more distant organs frequently take place; death rapidly ensuing.

Cysts are very rare, occasionally arising from remnants of Mueller's ducts or from obstruction to the ducts.

Cowper's Glands

These become involved in the course of inflammations of the prostate gland or of the urethra. The glands become hyperemic, enlarge, and may suppurate. The abscess may rupture into the urethra or externally, in either case giving rise to a fistula. The duct may become narrowed as a result of inflammation and form a retention cyst.