Prostate
Granulomatous lesions
General

Authors: Gladell Paner, M.D. (see Authors page)

Revised: 19 July 2016, last major update February 2012

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PubMed search: prostatic granulomatous lesions
Definition / General
  • Seen in 0.8% of benign prostate specimens and 0.3% of prostate needle biopsies
  • Non-specific granulomatous prostatitis most common, comprising 50-78%
  • Includes non-specific, post-procedural, iatrogenic, infectious, systemic and secondary granulomatous prostatitis (Hum Pathol 1984;15:818, BJU Int 2007;99:510)
Etiology
  • Post-procedural (post-transurethral resection and post-needle biopsy granulomas)
  • Infectious causes include Bacillus Calmette-GuĂ©rin (BCG)-related granuloma, bacterial (Mycobacterium tuberculosis [most common], Treponema pallidum, Brucella abortus), fungal (blastomycosis, Cryptococcus), parasitic (schistosomiasis) and viral (Herpes zoster)
  • Secondary to systemic granulomas such as allergic (eosinophilic) granulomatous prostatitis and Churg-Strauss syndrome
Clinical Features
  • 2/3 occur at ages 50-70 years
  • May present with irritative voiding symptoms (e.g urgency, frequency, dysuria), fevers or chills, but asymptomatic in 10%
  • Firm nodular prostate on digital rectal examination may be suspicious for carcinoma
  • PSA may be elevated
  • May coexist with prostate carcinoma
Treatment
  • Most require no treatment
  • May require prostatectomy to relieve obstructive symptoms
  • Antibiotics for infections and steroids for systemic granulomas
Gross Description
  • Firm yellow nodular prostate
Micro Description
  • Non-specific: expansile nodular infiltrates usually involving entire lobules with epithelioid histiocytes, lymphocytes, plasma cells, neutrophils and variable eosinophilc infiltrates (Arch Pathol Lab Med 1997;121:724)
  • Post-transurethral resection: resembles rheumatoid nodules with necrobiotic granolumas surrounded by palisaded histiocytes and frequent multinucleated giant cells (J Urol 1988;140:751)
  • BCG-related: multiple caseating and non-caseating granulomas; acid-fast bacilli in 1/3
  • Allergic: necrobiotic granulomas surrounded by palisaded histiocytes with variable eosinophilic infiltrates