Testis & paratestis
Nonneoplastic lesions
Infectious orchitis
Author: Sean R. Williamson, M.D.
Last author update: 1 December 2012
Last staff update: 10 September 2020
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: Infectious testicular lesions
Table of Contents
AIDS | Brucellosis | Gonorrhea | Histoplasma capsulatum | Leprosy | Mumps | Pyogenic epididymo-orchitis | Syphilis | Tuberculosis | Gross images | Microscopic (histologic) imagesCite this page: Williamson S. Infectious orchitis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testisinfectious.html. Accessed March 22nd, 2023.
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
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
- Three phases of testicular involvement:
- Vascular phase: blood vessels show perivascular lymphocytic inflammation and interstitium is filled with macrophages containing mycobacteria
- Interstitial phase: endarteritis, Leydig cell clusters, interstitial fibrosis, histiocytes containing acid fast bacteria and reduced spermatogenesis
- 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
- 1/3 of infected postpubertal men develop testicular atrophy, 2 - 10% become infertile
- Incidence increasing, due to reduced use of vaccine (BJU Int 2010;105:1060)
Pyogenic epididymo-orchitis
- Usually due to E. coli
- Resembles granulomatous orchitis
- Complications: venous thrombosis, septic testicular infarct
Syphilis
Tuberculosis
- Usually begins in epididymis and spreads to testis
- Prostate and seminal vesicles are usually also infected
Gross images
Contributed by Yale Rosen, M.D.
TB orchitis
Images hosted on other servers:
Brucellosis
Microscopic (histologic) images
Contributed by Sean R. Williamson, M.D.
Tuberculosis involving testis and paratestis
