DISEASES OF THE PROSTATE

Prostatitis is inflammation of the prostate. Prostatitis may be acute, chronic and granulomatous types.

Acute prostatitis. Acute focal or diffuse suppurative inflammation of the prostate is not uncommon. It occurs most commonly due to ascent of bacteria from the urethra, less often by descent from the upper urinary tract or bladder, and occasionally by lymphogenous or hematogenous spread from a distant focus of infection. The infection may occur spontaneously or may be a complication of urethral manipulation such as by catheterisation, cystoscopy, etc. The common pathogens are E. coli, and others such as Klebsiella, Proteus, Pseudomonas, Entero-bacter, gonococci, staphylococci and streptococci.

Morphology. Macroscopically, the prostate is enlarged, swollen and tense. Cut section shows multiple abscesses and foci of necrosis. Microscopically, the prostatic acini are dilated and filled with neutrophilic exudate. There may be diffuse acute

inflammatory infiltrate. Edema, hyperemia and foci of necrosis frequently accompany acute inflammatory involvement.

Chronic prostatitis. Chronic prostatitis is more common and foci of chronic inflammation are frequently present in the prostate of men above 40 years of age. Chronic prostatitis is usually asymptomatic but may cause allergic reactions, iritis, neuritis or arthritis. Chronic prostatitis is of 2 types—bacterial and abacterial.

Chronic bacterial prostatitis is caused in much the same way and by the same organisms as the acute prostatitis.

Chronic abacterial prostatitis is more common these days. Prostatic secretions is always negative, though leucocytosis is demonstrable in prostatic secretions. The pathogens implicated are Chlamydia trachomatis and Ureaplasma urealyticum.

Morphology. Macroscopically, the prostate may be enlarged, fibrosed and shrunken. Microscopically, the diagnosis of chronic prostatitis is made by foci of lymphocytes, plasma cells, macrophages and neutrophils within the prostatic substance. Prostatic calculi and foci of squamous metaplasia in the prostatic acini may accompany inflammatory changes.

Granulomatous prostatitis. Granulomatous prostatitis is a variety of chronic prostatitis, probably caused by leakage of prostatic secretions into the tissue, or could be of autoimmune origin.

Morphology. Macroscopically, the gland is firm to hard, giving the clinical impression of psoriatic carcinoma on rectal examination. Microscopically, the inflammatory reaction consists of macrophages, lymphocytes, plasma cells and some multinucleated giant cells.

Nodular hyperplasia. Non-neoplastic tumour-like enlargement of the prostate, commonly termed benign nodular hyperplasia or benign enlargement of prostate, is a very common condition in men. It becomes increasingly more frequent above the age of 50 years and its incidence approaches 75—80 % in men above 80 years.

The cause of benign nodular hyperplasia has not been fully established. A few etiologic factors such as endocrinologic, racial, inflammation and arteriosclerosis have been implicated but endocrine basis for hyperplasia has been more fully investigated and considered a strong possibility in its genesis. It has been found that both sexes elaborate androgen and estrogen, though the level of androgen is high in males and that of estrogen is high in females. With advancing age, there is decline in the level of androgen and a corresponding rise of estrogen in the males. The periurethral inner prostate which is primarily involved in benign nodular hyperplasia is responsive to the rising level of estrogen, whereas the outer prostate

which is mainly involved in the carcinoma is responsive to androgen.

Morphology. Macroscopically, the enlarged prostate is nodular, smooth and firm and weighs 2—4 times its normal weight i.e. may weigh up to 40— 80 gm. The appearance on cut section varies depending upon whether the hyperplasia is predominantly of the glandular or fibromuscular tissue. In primarily glandular benign nodular hyperplasia the tissue is yellow-pink, soft, honey-combed, and milky fluid exudes, whereas in mainly fibromuscular benign nodular hyperplasia the cut surface is firm, homogeneous and does not exude milky fluid. The hyperplastic nodule forms a mass mainly in the inner periurethral prostatic gland so that the surrounding prostatic tissue forms a false capsule which enables the surgeon to enucleate the nodular masses.

Microscopically, in every case, there is hyperplasia of all three tissue elements in varying proportions — glandular, fibrous and muscular.

Glandular hyperplasia predominates in most cases and is identified by exaggerated intra-acinar papillary infoldlngs with delicate fibrovascular cores. The lining epithelium is two-layered: the inner call columnar mucus-secreting with poorly-defined borders, and the outer cuboidal to flattened epithelium with basal nuclei.

Fibromuscular hyperplasia when present as dominant component appears as aggregates of spindle

cells forming an appearance akin to fibromyoma of the uterus.

Carcinoma of prostate. Cancer of the prostate is the second most common form of cancer in males, followed in frequency by lung cancer. It is a disease of men above the age of 50 years and its prevalence increases with increasing age so that 60% or more of men 80 years old have asympto-matic carcinoma of the prostate. There are following types carcinoma of the prostate.

Latent carcinoma. This is found unexpectedly as a small focus of carcinoma in the prostate during autopsy studies in men dying of other causes. Its incidence in autopsies has been variously reported as 25—35%.

Occult carcinoma. This is the type in which the patient has no symptoms of prostatic carcinoma but shows evidence of metastases on clinical examination and investigations.

Clinical carcinoma. Clinical prostatic carcinoma is the type detected by rectal examination and other investigations and confirmed by pathologic examination of biopsy of the prostate.

Nodular prostatic hyperplasia has been suggested by some as precursor for development of prostatic cancer.

Morphology. Macroscopically, the prostate may be enlarged, normal in size or smaller than normal. In

95% of cases, prostatic carcinoma is located in the peripheral zone, especially in the posterior lobe. The malignant prostate is firm and fibrous. Cut section is homogeneous and contains irregular yellowish areas. Microscopically, there are 4 histologic types of cancer of the prostate adenocarcinoma, transitional cell carcinoma, squamous cell carcinoma and undifferentiated carcinoma.