Granulomatous prostatitis (GP)
- Inflammation of prostate with granulomas (seen in <1% of prostate).
- Includes non-specific GP (most common), post-procedural GP (post-TUR), infectious GP (includes BCG-related, mycobacterial, fungal) and systemic GP (such as Churg-Strauss syndrome, Wegener granulomatosis).
- May present with irritative voiding symptoms, fever or chills.
- May present with palpable nodule (60%), raising suspicion for a carcinoma.
- Granuloma is characterized by central clusters of epithelioid histiocytes and surrounded by lymphocytic infiltrates.
- Non-specific GP shows expansile nodular mixed inflammatory infiltrates with rare discrete granulomas (image A).
- Post-resection GP shows central fibrinoid necrosis surrounded by palisaded histiocytes (looks like rheumatoid nodule) (image B).
- BCG-related granulomas have may have central caseation in larger granulomas, surrounded by histiocytes and with multinucleated giant cells (Langhans type) (image C); acid-fast bacilli demonstrable in ~38%.
- Group of inflammatory and non-inflammatory conditions of prostate characterized by GU or pelvic pain.
- Accounts for ~¼ of male clinical visits with GU complaints.
- NIH classification: Acute bacterial prostatitis, chronic bacterial prostatitis, chronic prostatitis/chronic pelvic pain syndrome and asymptomatic inflammatory prostatitis.
- Diagnosis requires clinical, microbiologic and laboratory correlation.
- Acute (image D) or chronic inflammation in prostate biopsies are NOT automatically labeled as "prostatitis" without clinical correlation.
- In the absence of other findings, incidental chronic inflammation in biopsy is categorized as asymptomatic inflammatory prostatitis.