Prostatitis
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Direct answer
Roughly nine of ten men labelled clinically with "chronic prostatitis" have no cultivable organism in the gland — they occupy category III of the four-part National Institutes of Health classification, chronic pelvic pain syndrome. Category I is acute bacterial prostatitis, a febrile Escherichia coli urinary infection in which neutrophils fill the glands; category II is chronic bacterial prostatitis, smouldering and relapsing with the same organism, driven by prostatic stones and ductal obstruction; category III splits into inflammatory (IIIa, leucocytes in expressed prostatic secretions) and non-inflammatory (IIIb, formerly prostatodynia); category IV is asymptomatic inflammation found incidentally in biopsies done for a raised prostate-specific antigen. Granulomatous prostatitis — post-surgical, tuberculous or bacille Calmette-Guerin-related — is the histological wildcard that mimics carcinoma clinically.
What you must remember
- NIH framework: I acute bacterial, II chronic bacterial, IIIa/IIIb chronic pelvic pain syndrome with or without leucocytes, IV asymptomatic — quote the number and the phrase together.
- Microbiology: Escherichia coli dominates both bacterial categories; other Enterobacteriaceae, enterococci and, in sexually active men, Chlamydia trachomatis account for the rest.
- Localisation tests: the Meares-Stamey four-glass test, or its simplified two-glass pre- and post-massage comparison, assigns organisms to the prostate rather than the urethra or bladder.
- Expressed prostatic secretion rule: more than 10 leucocytes per high-power field defines the inflammatory (IIIa) subset, with lipid-laden macrophages accompanying active inflammation.
- Granulomatous prostatitis sources: prior transurethral resection, tuberculosis, and intravesical BCG instillation for urothelial carcinoma — the last is a favourite Indian exam scenario.
- PSA lesson: both acute and chronic inflammation raise serum PSA, so infection must be treated and the test repeated before biopsy is committed.
- Therapy logic: fluoroquinolones for 2-4 weeks (category I) or 4-6 weeks (category II); category III gets alpha-blockers, anti-inflammatory agents and neuromodulatory strategies, not endless antibiotics.
Reading a biopsy that came out granulomatous
A 66-year-old treated with intravesical BCG for high-grade non-muscle-invasive bladder cancer undergoes prostate biopsy for a rising PSA. Instead of Gleason-patterned glands, the cores show non-caseating epithelioid granulomas with scattered giant cells rimmed by lymphocytes — BCG-related granulomatous prostatitis, reported after a substantial fraction of intravesical instillation courses. The pathologist's task is triage: stains for acid-fast bacilli exclude tuberculosis, and the intact residual acini with preserved basal cells (p63 and high-molecular-weight cytokeratin positive) exclude carcinoma. PSA falls over the following months without any oncological intervention. The same logic governs category IV disease found on random biopsies: inflammation is noted, scored for extent, and correlated with the PSA trend, but it neither demands treatment nor licenses a cancer label.
Where candidates slip
Two slips recur. First, acute bacterial prostatitis is made a contraindication to vigorous massage and biopsy — the fear is bacteraemia — so diagnosis rests on urine cultures and the tender, boggy gland, with blood cultures if septic. Second, candidates call category IIIb "psychological": it is a genuine pain syndrome with measurable central sensitisation, and the exam answer is multimodal therapy rather than antibiotics. The granuloma trap closes the set: on digital rectal examination a granulomatous prostate is firm and nodular enough to simulate carcinoma, and only histology separates them — which is precisely why the BCG history must reach the pathologist on the request form.
Frequently asked questions
Which NIH category covers chronic pelvic pain syndrome?
Category III, subdivided into IIIa (inflammatory, leucocytes in expressed prostatic secretions) and IIIb (non-inflammatory, formerly prostatodynia).
Which test localises infection to the prostate?
The Meares-Stamey four-glass test, comparing first-void urine, midstream urine, expressed prostatic secretions and post-massage urine; the two-glass pre- and post-massage version is the practical shortcut.
Why does intravesical BCG cause granulomatous prostatitis?
Attenuated mycobacteria reach the prostatic ducts and stroma through reflux, inducing epithelioid granulomas that can mimic carcinoma on rectal examination.
How does prostatitis affect PSA interpretation?
Both acute and chronic inflammation elevate PSA, so the value should be repeated after treatment before proceeding to biopsy.
How long should category II chronic bacterial prostatitis be treated?
Fluoroquinolones for 4-6 weeks, chosen for prostatic penetration, with reassessment for obstructing stones or ductal pathology if relapse follows.
What histology defines acute bacterial prostatitis?
Neutrophils streaming through and distending glandular lumina, sometimes with microabscesses, against an oedematous stroma.