Classification and Characteristics of Prostatic Inflammation
Inflammatory prostate diseases are classified by clinical course into acute and chronic forms. The etiology may be infectious (bacteria, viruses, fungi) or non-infectious, including prolonged secretory stasis. Often, the exact cause cannot be determined.
The primary mechanism of infectious forms is the reflux of infected urine from the lower urinary tract into the glandular ducts. Pathogens may also spread hematogenously via bacteremia or lymphogenously from the rectum.
Acute Bacterial Prostatitis
This is an acute non-specific inflammatory process most commonly induced by gram-negative flora (primarily E. coli), as well as enterococci, gonococci, or trichomonads. Predisposing factors include hypothermia, lower urinary tract infections, and sexually transmitted infections (STIs).
Macroscopically, the gland is diffusely or focally swollen and firm. Inflammation progresses through three sequential morphological stages:
- Catarrhal: Marked stromal edema, vascular congestion, and neutrophil accumulation within the ducts.
- Follicular: The inflammatory infiltrate extends to the secretory units (acini).
- Parenchymal: Diffuse neutrophilic infiltrates form, accompanied by microabscesses and foci of granulation tissue proliferation.
Without appropriate therapy, the condition may lead to acute urinary retention and urogenic sepsis.
Chronic Forms of Prostatitis
Chronic inflammation may be a primary disease or a sequel to undertreated acute prostatitis. Several main variants are distinguished:
- Chronic bacterial prostatitis: Frequently caused by intracellular microorganisms (Chlamydia trachomatis, mycoplasmas, ureaplasmas). It is provoked by physical inactivity, irregular sexual activity, and dietary factors. Macroscopically, the gland is deformed and firm. Microscopically, the stroma shows focal accumulations of lymphocytes, macrophages, and plasma cells, along with fibrous tissue proliferation. The disease has a protracted course, responds poorly to therapy, and may be complicated by infertility.
- Chronic non-bacterial prostatitis: The most common form, occurring predominantly in men over 50. Microscopically, glandular lumens are dilated and contain lipid-laden macrophages and neutrophils, while the stroma is infiltrated by lymphocytes.
- Chronic granulomatous prostatitis: A rare, specific pathology associated with tuberculosis, syphilis, or fungal infections. It is characterized by the formation of specific granulomas and fibrosis.
- Malakoplakia: A distinct type of chronic granulomatous inflammation in which glandular atrophy is accompanied by ductal epithelial metaplasia.
Benign Prostatic Hyperplasia and Tumors
In addition to inflammatory processes, dyshormonal and oncological changes frequently develop in the prostate tissue.
Benign Prostatic Hyperplasia (BPH) is the most common neoplasm of the male reproductive system, affecting the periurethral zone. The risk of development increases sharply with age (from 25% in 50-year-old men to 90% in 70-year-olds). The pathogenesis is based on elevated estrogen levels (due to testosterone conversion) and concomitant chronic inflammation.
Macroscopically, the gland enlarges and acquires a firm-elastic consistency. Nodules form and compress the urethra, triggering a cascade of complications ranging from hydronephrosis to urogenic sepsis. The most common histological form is simple nodular hyperplasia, where branched acini predominate over the stroma.
High-grade Prostatic Intraepithelial Neoplasia (PIN) is considered an obligate precancerous lesion that typically transitions into prostate cancer (most commonly adenocarcinoma). Prostate cancer is diagnosed via total and free prostate-specific antigen (PSA) testing, transrectal ultrasound (TRUS), and biopsy.