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Nonneoplastic lesions

Granulomatous lesions of testis and paratestis

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Cite this page: Williamson SR. Granulomatous lesions of testis and paratestis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testisorchitis.html. Accessed April 25th, 2024.

Definition / general

Rare; usually men 40 - 59 years with sudden onset of tender testicular mass, variable fever
May be a response to acid fast products of disintegrated sperm, postinfectious or due to trauma or sarcoidosis
Resembles pyogenic epididymo-orchitis
Benign, although granulomatous inflammation may be associated with seminoma
Recommend cultures to rule out infectious process (brucellosis, leprosy, sarcoidosis, syphilis, TB)
Granulomatous ischemic lesion
- Usually affects head of epididymis
- May be due to ischemia with secondary granulomatous reaction and scarring
Gross description
- Solid, unilateral nodular enlargement of testis; resembles lymphoma
Microscopic (histologic) description
- Lymphocytes and plasma cells infiltrate interstitium and surround seminiferous tubules
- Giant cells and histiocytes that resemble (but are not) actual granulomas
- Granulomatous ischemic lesion
  - Zone of necrosis involving efferent ducts and interstitial connective tissue, with adjacent lymphocytes and macrophages
  - Macrophages form large clusters with cholesterol crystals and foreign body type giant cells in duct lumen
  - Also intratubular epithelial regeneration and proliferation of small ducts showing epithelial regeneration and numerous spermatozoa in their lumen
  - Associated with ceroid granuloma, spermatic granuloma and epidermoid metaplasia of the efferent ducts
Reference: Am J Surg Pathol 1997;21:951

Infectious causes

AIDS

Associated with markedly reduced spermatogenesis, arrested maturation, germ cell aplasia, tubular hyalinization / thickening of basement membranes, interstitial inflammation and fibrosis, reduction in Leydig cells, Sertoli cell only pattern (J Pathol 1991;163:47, Urology 1999;53:203, Mod Pathol 1989;2:233, Hum Pathol 1989;20:210)
Often other infections in testis or epididymis (Candida, CMV, Histoplasma, mycobacteria, toxoplasmosis)
Testicular atrophy related findings do not appear to be immune mediated (Hum Pathol 1989;20:572)
Testis is an uncommon location for Kaposi sarcoma in AIDS patients

Brucellosis

Zoonotic infection acquired from sheep, camels, cattle, dogs, goats, reindeer, swine via skin / mucous membrane contact or contaminated animal products
Affects testis and epididymis (epididymo-orchitis) in 2 - 20% of cases, causing scrotal pain, swelling, fever
Often diagnosed by laboratory studies
Case report: 32 year old man with painless testicular mass-brucellosis (Int J Urol 2004;11:683)
Micro description: granulomatous or testicular abscess
Treatment: antibiotics; orchiectomy if resembles a neoplasm or refractory to therapy
Additional references: Urol Int 2009;82:158, BMC Res Notes 2011;4:286, Clin Infect Dis 2001;33:2017

E. coli related pyogenic epididymo-orchitis

Usually due to E. coli
Resembles granulomatous orchitis
Complications: venous thrombosis, septic testicular infarct

Gonorrhea

Usually spreads from posterior urethra to prostate, seminal vesicles and epididymis
Testis involved only if untreated

Histoplasma capsulatum

Rarely presents as testicular mass
May resemble sperm granuloma (J Clin Pathol 1974;27:929)
Caseating granulomatous inflammation with giant cells
Small yeast forms (2 - 5 micrometers) are identifiable by silver stain (J Urol 2000;164:1652)

Leprosy

Does not occur in U.S.
Rarely presents with orchitis (Am J Clin Pathol 1980;73:712)
Testicular involvement thought to be facilitated by lower temperature of scrotum
3 phases of testicular involvement
1. Vascular phase: blood vessels show perivascular lymphocytic inflammation and interstitium is filled with macrophages containing mycobacteria
2. Interstitial phase: endarteritis, Leydig cell clusters, interstitial fibrosis, histiocytes containing acid fast bacteria and reduced spermatogenesis
3. Obliterative phase: dense fibrosis, no detectable tubules, reduced vessels, rare acid fast bacteria; associated with gynecomastia and infertility

Mumps

Testicular infections rare in infected children (prepubertal) but occur in 15 - 40% of postpubertal men one week after parotiditis
Usually unilateral (bilateral in 15 - 30%); epididymitis is also common (85%) and often precedes orchitis
33% of infected postpubertal men develop testicular atrophy, 2 - 10% become infertile
Incidence increasing, due to reduced use of vaccine (BJU Int 2010;105:1060)

Syphilis

Testis usually involved first
Discrete gummas contribute to enlarged, irregular testis
Gummas: diffuse interstitial inflammation with edema, lymphocytes and plasma cells, with obliterative endarteritis and perivascular cuffing
Spirochetes usually identified in gummatous but not fibromatous stages

Tuberculosis