Inflammation and Infections

Slide 1 · Inflammation and Infections

Testis and Epididymis

Pathologic patterns, mechanisms, and clinicopathologic consequences

Dr Abu Suraih Sakhri

MBBS, MD (Pathology)

www.abusuraihsakhri.com

Slide 2 · Learning outcomes

Localize the initial site of epididymal and testicular inflammation.

Relate age and route of infection to likely causes.

Recognize acute, granulomatous, lymphoplasmacytic, and vascular inflammatory patterns.

Explain suppuration, fibrous scarring, and fertility-related consequences.

Slide 3 · The two organs form a connected inflammatory field

Testis

Epididymis

Vas deferens

The epididymis connects anatomically with the testis and duct system.

Pathogens may ascend from other genitourinary sites.

Site of earliest involvement helps organize the differential diagnosis.

Slide 4 · Inflammatory disease is more frequent in the epididymis

Epididymis

Inflammatory disorders occur here more often.

May be the primary site before secondary testicular involvement.

Testis

May be involved through contiguous spread.

Certain infections preferentially begin in the testis.

Slide 5 · Initial site varies with the etiology

Epididymis first

Gonorrhea and tuberculosis commonly begin in the epididymis.

Subsequent testicular involvement may occur.

Testis first

Syphilis and mumps characteristically involve the testis first.

These do not follow the same typical anatomic sequence.

Site of onset is an organizing clue, not a substitute for etiologic confirmation.

Slide 6 · The inflammatory reaction provides a second diagnostic axis

Pattern

Source-linked examples

Characteristic finding

Acute suppurative

Bacterial epididymitis; Gonorrhea

Neutrophils, edema ± abscess

Granulomatous

Idiopathic orchitis; Tuberculosis

Tubule-limited vs caseating granulomas

Interstitial mononuclear

Mumps orchitis

Lymphocytes and plasma cells

Vascular / granulomatous

Syphilis

Endarteritis or gumma

Slide 7 · Epididymitis often follows an infection elsewhere in the GU tract

Cystitis / urethritis / prostatitis

Spread toward epididymis

Acute epididymal inflammation

Possible secondary orchitis

Vas deferens and spermatic-cord lymphatics as routes of spread.

Slide 8 · The vas deferens is a pathway of extension

Genitourinary infection

Vas deferens

Epididymis

Testis may become involved

Conceptual pathway; Not a claim about the route in every patient.

Slide 9 · Spermatic-cord lymphatics offer another route

Urinary / genital infection

Spermatic-cord lymphatics

Epididymitis

Orchitis may follow

Robbins explicitly identifies this as an alternative to spread through the vas deferens.

Slide 10 · Associated urinary tract sites matter

Cystitis

Bladder involvement precedes or accompanies some cases.

Urethritis

Urethral infection can extend to proximal genital tract.

Prostatitis

Prostatic infection is a documented antecedent site.

Slide 11 · Likely bacterial causes vary with age

Clinical group

Associations

Teaching emphasis

Childhood (uncommon)

Congenital GU abnormality; Gram-negative rods

Consider accompanying anatomic abnormality

Sexually active males <35 years

C. Trachomatis; N. Gonorrhoeae

Sexually transmitted pathogens predominate

Males >35 years

E. Coli; Pseudomonas

Common urinary tract organisms predominate

Slide 12 · Childhood epididymitis has a distinctive association

Epididymitis is uncommon in children.

When it occurs, it commonly to congenital genitourinary abnormalities.

Gram-negative rods are the typical associated pathogens.

The age association is a clue, not organism identification.

Slide 13 · In sexually active younger males, STI pathogens predominate

Chlamydia trachomatis

One of the most frequent pathogens named in this age group.

Located within the sexually transmitted etiologic category.

Neisseria gonorrhoeae

Another major sexually transmitted cause.

Severe disease may become destructive and suppurative.

Slide 14 · After 35 years, common urinary pathogens predominate

Escherichia coli

Named as a common urinary tract cause.

Fits the association with infections at other GU sites.

Pseudomonas

Also named among common causative urinary organisms.

The textbook does not provide a patient-level diagnostic rule.

Slide 15 · Age-based associations are not definitive diagnoses

Age organizes likely etiologies at the population level.

The disease mechanism also depends on the involved genitourinary sites and spread route.

A named pathogen cannot be proven by age or morphology alone.

Use the age framework as teaching context, not a stand-alone diagnostic algorithm.

Slide 16 · Bacterial inflammation produces a stereotyped acute reaction

Bacterial infection

Vascular congestion + edema

Neutrophilic infiltration

Possible suppuration

These morphology stages are connected conceptually; Their prominence varies with disease severity.

Slide 17 · Congestion represents the vascular component of acute inflammation

Bacterial epididymitis is associated with vascular congestion.

Congestion accompanies the early inflammatory response.

It occurs together with tissue edema and neutrophil entry.

The combination is characteristic of acute bacterial inflammation.

Slide 18 · Edema expands inflamed interstitial tissue

Schematic — not a histologic specimen

Edema is explicitly described in the acute bacterial lesion.

The inflammatory process commonly starts in interstitial connective tissue.

Tubules may be secondarily affected as inflammation extends.

Slide 19 · Neutrophils are the defining acute inflammatory cells

Schematic — not a histologic specimen

Acute bacterial infection produces infiltration by neutrophils.

Neutrophil-rich inflammation may accompany tissue destruction.

A severe lesion can progress to abscess formation.

Slide 20 · The initial bacterial lesion is usually interstitial

Schematic — not a histologic specimen

The process generally begins in connective tissue between tubules.

It is not initially confined to the tubular lumen.

Progression can rapidly involve the tubules themselves.

Slide 21 · Inflammation can extend into epididymal tubules

Schematic — not a histologic specimen

The expanding acute infiltrate may reach the tubular compartment.

Tubular involvement indicates progression beyond the initial interstitial focus.

Destructive disease can culminate in abscess or necrosis.

Slide 22 · Suppuration is a potential endpoint of severe bacterial disease

Interstitial inflammation

Tubular extension

Intense neutrophilic injury

Abscess / suppurative necrosis

The source describes possible—not inevitable—progression to destructive infection.

Slide 23 · An epididymal abscess is a destructive lesion

Schematic — not a histologic specimen

Abscess formation is a recognized consequence of severe epididymitis.

The normal epididymal tissue can be substantially replaced.

Localized suppuration may replace much of the affected epididymal tissue.

Slide 24 · Extensive necrosis can destroy the epididymis

Suppurative necrosis of the entire epididymis in severe cases.

This is the extreme end of neutrophil-dominated tissue injury.

It represents a qualitatively different consequence from edema alone.

Subsequent healing may involve fibrous replacement.

Slide 25 · Secondary orchitis can follow epididymal inflammation

Epididymal infection

Extension to testis

Similar inflammatory reaction

Potential later scarring

The sequence is an important pattern for several infections, but not all etiologies begin in the epididymis.

Slide 26 · Healing may leave fibrous scarring

Acute inflammation

Tissue injury

Healing with fibrosis

Potential impairment of fertility

Fibrous scarring following epididymitis/orchitis is explicitly linked to sterility in the source.

Slide 27 · Fertility can be impaired after epididymo-orchitis

Fibrous scarring can follow inflammation of the epididymis and testis.

Robbins explicitly identifies sterility as a possible consequence.

The reproductive outcome reflects injury to the genital tract and its tissue architecture.

A reversible acute episode does not guarantee reversal of established scarring.

Slide 28 · Leydig cells are usually relatively spared

Inflamed tissue

Epididymal and testicular compartments may show neutrophils and scarring.

The seminiferous / ductal apparatus may be compromised.

Leydig cells

Usually not destroyed by the inflammatory process.

Androgen production is therefore relatively unaffected.

Slide 29 · Fertility and androgen production may diverge

Outcome

Source-supported interpretation

Fertility

May be reduced or lost after postinflammatory scarring

Androgen output

Relatively preserved because Leydig cells are usually spared

Key distinction

Preserved androgen output does not exclude reproductive sequelae

Slide 30 · Bacterial epididymo-orchitis: Integrated tissue course

Antecedent infection

Cystitis, urethritis, or prostatitis

Early lesion

Congestion, edema, neutrophils

Progression

Tubular spread, abscess or necrosis

Sequelae

Fibrous scarring; Possible sterility

Slide 31 · Gonorrhea can ascend from the posterior urethra

Posterior urethra

Prostate and seminal vesicles

Epididymis

Possible testicular involvement

This extension with neglected gonococcal infection.

Slide 32 · Severe gonococcal epididymitis may form abscesses

Untreated / neglected gonococcal infection can extend to the epididymis.

Severe epididymal infection may cause abscesses.

Abscesses may lead to extensive destruction and scarring.

Gonorrhea is therefore an example of potentially destructive suppuration.

Slide 33 · Gonococcal infection may also produce suppurative orchitis

Epididymal component

Ascending genital tract infection.

Abscess formation and tissue destruction may occur.

Testicular component

Can follow spread from the epididymis.

Suppurative orchitis is a reported manifestation.

Slide 34 · Granulomatous orchitis may be idiopathic

Idiopathic granulomatous orchitis is described as rare.

It is predominantly a testicular inflammatory disorder.

The defining histologic feature is granulomas restricted to spermatic tubules.

Its cause remains uncertain description.

Slide 35 · Idiopathic granulomatous orchitis often presents in middle age

The usual patient is middle-aged.

Presentation may be a moderately tender testicular mass of sudden onset.

Fever may accompany the abrupt presentation.

A more indolent, painless presentation is also described.

Slide 36 · Granulomatous orchitis may clinically mimic a tumor

A middle-aged patient has an insidiously developing, painless testicular mass. The pathologic process ultimately proves inflammatory.

Which Robbins-listed inflammatory disorder is a key tumor mimic?

Idiopathic granulomatous orchitis; A painless testicular mass is a described presentation.

Slide 37 · Tubule-restricted granulomas are a defining microscopic clue

Granulomas inside

Spermatic tubule

Tubule boundary

Conceptual pattern — not a photomicrograph

Idiopathic granulomatous orchitis is characterized by granulomas within spermatic tubules.

This localization is highlighted as distinctive.

Interpret morphology alongside clinical and infectious context.

Slide 38 · Several causes of idiopathic granulomatous orchitis are postulated

Proposed mechanisms

Trauma

Infection

Extravasated sperm

Autoimmune process

These are hypotheses identified—not established causes for every case.

Slide 39 · Distinguish idiopathic granulomatous orchitis from tuberculosis

Feature

Idiopathic granulomatous orchitis

Tuberculous involvement

Primary clue

Granulomas confined to spermatic tubules

Often begins in epididymis

Necrosis

No defining caseation described

Caseating granulomatous inflammation

Diagnostic caution

Can mimic a neoplasm

Can resemble another granulomatous process

Slide 40 · Genital tuberculosis usually begins in the epididymis

Tuberculous infection involving genital tract

Epididymal focus

Possible extension to testis

Caseating granulomatous reaction

“Almost invariably begins in the epididymis” is the textbook formulation.

Slide 41 · Caseating granulomas are the characteristic TB reaction

Caseation

Conceptual pattern — not a photomicrograph

Male genital tuberculosis evokes caseating granulomatous inflammation.

The reaction is analogous to tuberculosis elsewhere in the body.

This pattern differs from tubule-limited idiopathic granulomatous orchitis.

Slide 42 · Epididymal location and caseation help distinguish TB

Anatomic distribution

Tuberculosis almost invariably begins in the epididymis.

The testis can become involved secondarily.

Histopathologic pattern

Caseating granulomatous inflammation is characteristic.

Location and necrosis should be interpreted together.

Slide 43 · Mumps orchitis is strongly influenced by pubertal status

School-aged children

Mumps commonly affects this age group.

Testicular involvement is extremely uncommon.

Postpubertal males

Orchitis is substantially more frequent.

Orchitis in 20%–30% of cases.

Slide 44 · Orchitis in 20%–30% of postpubertal mumps cases

This range pertains to postpubertal males with mumps.

It does not refer to school-aged children, in whom orchitis is very uncommon.

The figure is reproduced as textbook information, not a current population estimate.

Age context is essential when interpreting the percentage.

Slide 45 · Mumps orchitis typically follows parotid swelling

Systemic mumps

Parotid gland swelling

Approximately 1 week later

Orchitis may develop

Inflammatory lesion

Acute interstitial orchitis

Possible consequence

Reduced fertility if bilateral

Slide 46 · Mumps orchitis has an interstitial mononuclear infiltrate

Schematic — not a histologic specimen

The characteristic reaction is acute interstitial orchitis.

Infiltrating lymphocytes and plasma cells are emphasized.

This differs in dominant cell type from acute bacterial neutrophilic inflammation.

Slide 47 · Bilateral mumps orchitis can reduce fertility

Mumps may involve the testis in postpubertal males.

Bilateral testicular involvement is the context in which reduced fertility is emphasized.

Testicular-first involvement contrasts with many ascending infections.

The source does not establish inevitable infertility in every affected patient.

Slide 48 · Bacterial and mumps orchitis differ in dominant morphology

Aspect

Typical bacterial process

Mumps orchitis

Usual initial site

Epididymis often first

Testis first

Inflammatory cells

Neutrophils

Lymphocytes, plasma cells

Tissue pattern

Congestion; Edema; Suppuration possible

Acute interstitial orchitis

Fertility concern

Fibrous scarring

Bilateral involvement

Slide 49 · Syphilis commonly involves the testis first

Site and setting

Acquired and congenital syphilis may involve male genital organs.

The testis is almost invariably the first involved site.

Major tissue reactions

Obliterative endarteritis with perivascular inflammatory cuffs.

Granulomatous inflammation forming a gumma.

Slide 50 · Obliterative endarteritis is a syphilitic pattern

Narrowed lumen

Schematic vessel cross-section

Obliterative endarteritis as a characteristic reaction.

The vessel-centered lesion is associated with inflammatory cuffs.

This vascular pattern contrasts with typical neutrophilic epididymitis.

Slide 51 · Perivascular cuffs contain lymphocytes and plasma cells

Schematic — not a histologic specimen

The perivascular inflammatory infiltrate is lymphoplasmacytic.

It accompanies the obliterative vascular lesion in syphilis.

The cell population should be interpreted with its vascular distribution.

Slide 52 · A gumma is the granulomatous syphilitic pattern

Gumma

Conceptual pattern — not a photomicrograph

Syphilis can also produce granulomatous inflammation.

This form is named a gumma.

It as an alternative to obliterative endarteritis.

Slide 53 · Syphilis has two described morphologic expressions

Vascular pattern

Obliterative endarteritis.

Perivascular lymphocytes and plasma cells.

Granulomatous pattern

Gummatous inflammation.

A distinct alternative reaction described in the source.

Slide 54 · Not all rare orchitis causes are infections

Additional infectious causes

Leprosy; Toxoplasmosis; Fungi.

Other viruses; Parasites; Brucellosis.

Other inflammatory associations

Sarcoidosis and Crohn disease are noninfectious conditions.

Malakoplakia is also listed among rare causes.

Slide 55 · Less common infectious etiologies are heterogeneous

Bacterial / related

Leprosy and brucellosis are listed.

Parasites

Toxoplasmosis and other parasitic causes are listed.

Fungal / viral

Fungi and other viruses are listed.

Slide 56 · Systemic inflammatory disease may be associated with orchitis

Sarcoidosis and Crohn disease appear list of rare causes.

These diagnoses should not be mislabeled as microbial infections.

The supplied source gives no specific testicular histologic signature for either condition.

They belong in the broader differential for inflammatory testicular pathology.

Slide 57 · The initial organ often predicts the relevant differential

First site

Examples emphasized

Interpretive caution

Epididymis

Gonorrhea; Tuberculosis; Bacterial epididymitis

Secondary orchitis may follow

Testis

Mumps; Syphilis

Do not presume ascending epididymal infection

Primarily intratubular

Idiopathic granulomatous orchitis

Morphologic localization is a clue, not complete proof

Slide 58 · Inflammatory cell type and necrosis refine interpretation

Finding

Most directly associated process

Neutrophils, abscess, suppurative necrosis

Bacterial epididymitis / gonorrhea

Granulomas restricted to spermatic tubules

Idiopathic granulomatous orchitis

Caseating granulomas with epididymal focus

Tuberculosis

Interstitial lymphocytes and plasma cells

Mumps

Vessel-centered lymphoplasmacytic cuffs ± gumma

Syphilis

Slide 59 · Application: An acute suppurative epididymal lesion

A sexually active younger adult has evidence of acute epididymal inflammation. Histology demonstrates neutrophils and an abscess.

Which organisms and complication fit the source-based pattern?

C. Trachomatis or N. Gonorrhoeae are frequent in this age group; Severe gonorrheal epididymitis can form destructive abscesses.

Slide 60 · Application: Orchitis after parotid swelling

A postpubertal patient develops testicular inflammation approximately one week after parotid swelling. The infiltrate is interstitial and lymphoplasmacytic.

Which etiology and potential reproductive concern are most directly supported?

Mumps orchitis; Bilateral disease may reduce fertility.

Slide 61 · Application: A granulomatous testicular mass

A middle-aged patient has a testicular mass. Granulomas are restricted to spermatic tubules, and caseating necrosis is not described.

Which diagnosis is favored, and which important mimic remains?

Idiopathic granulomatous orchitis is favored by intratubular distribution; Tuberculosis remains a key granulomatous differential.

Slide 62 · Application: Testis-first vessel-centered inflammation

Testicular pathology shows obliterative endarteritis and perivascular lymphocytes with plasma cells.

Which infection produces this characteristic morphologic reaction?

Syphilis; A gumma is the other principal histopathologic pattern described.

Slide 63 · Read a testicular inflammatory lesion along four axes

Integrated evaluation

Initial site

Cellular pattern

Organism / context

Potential sequelae

A structured synthesis of observations in the supplied chapter; Not a clinical testing guideline.

Slide 64 · Core synthesis: Distribution, morphology, and function

Recognize

Epididymis-first: Common bacterial infections, gonorrhea, tuberculosis.

Testis-first: Mumps and syphilis.

Intratubular granulomas: Idiopathic granulomatous orchitis.

Explain

Neutrophilic injury may cause abscess and necrosis.

Fibrosis may impair fertility.

Leydig sparing may preserve androgen output.

Slide 65 · Source reference

Robbins, Cotran & Kumar: Pathologic Basis of Disease. 11th edition (2026).

Section: Inflammation and Infections of the Testis and Epididymis, including the immediately adjacent subsections.

All diagrams in this lecture are original editable schematics, not reproduced histopathology images or diagnostic evidence.