Inflammatory lesions of the testis and epididymis. Cryptorchidism and testicular atrophy

1. Overview

• Inflammatory lesions are more common in epididymis than in testis proper.
• Causes: STDs, non-specific epididymitis + orchitis, mumps, TB.
• Granulomatous inflammation can be caused by infections, autoimmune injury, TB.

2. Epididymitis

• Inflammation of the epididymis (sperm maturation + storage).
• Most frequent cause of acute scrotal pain.
• Related to primary UTI ascending via vas deferens / lymphatics to testes.
• Scrotum becomes red, warm, swollen → may cause testicular ischemia + necrosis.
• Often related to gonorrhea, syphilis, or TB.
• In sexually active men: Chlamydia trachomatis = most frequent causative microbe.
• In older men: E. coli + Pseudomonas (urinary pathogens).

3. Orchitis

• Inflammation of one or both testicles.
• Same etiology as epididymitis (ascending UTI).
• Sx: hemospermia, hematuria, testicular swelling.

Mumps orchitis

• Mumps virus (Paramyxovirus) family.
• Rarely in children; 15–40 % of adult males ~1 week after parotitis.
• May cause loss of seminiferous epithelium → testicular atrophy + fibrosis + sterility.

4. Chronic Inflammatory Lesions

A) Tuberculosis

• Granulomatous inflammation + caseous necrosis in testis.
• Usually begins in epididymis → spreads to testis, prostate, seminal vesicles.
• Histology: identical to TB at other sites.

B) Granulomatous orchitis (autoimmune)

• Related to trauma; autoimmune reaction to spermatic antigens.

C) Syphilis (T. pallidum)

• Three phases:
  • Primary: painless hard ulcer (ulcus durum / chancre).
  • Secondary: rash + condyloma lata.
  • Tertiary: gummas (syphilitic granulomas with epithelioid + giant cells, obliterative endarteritis, necrosis) + neurosyphilis.

5. Cryptorchidism

Definition

• Absence of one or both testes in scrotum due to failure of intra-abdominal testes to descend.
• 10 % bilateral.

Causes

• Multiple influences interfere with descent:
  • Hormonal abnormalities.
  • Intrinsic testicular abnormalities.
  • Obstruction of inguinal canal.
• Associations: Prader-Willi syndrome, trisomy 13, Kallmann syndrome.
• Most cases: idiopathic.

Clinical features

• Sterility (if bilateral).
• 3–5× ↑ risk of testicular malignancy (especially seminoma).
• Other complications: trauma, torsion, inguinal hernia.
• Orchiopexy (surgical placement of testis in scrotum) before puberty reduces sterility + malignancy risk.

6. Testicular Atrophy + Male Infertility

Definition

• Infertility = any problem in a man that lowers chances of female partner becoming pregnant.
• Usually due to semen deficiencies (oligospermia, azoospermia, asthenospermia).

Causes

Pre-testicular (poor hormonal/general support)

• Hypogonadism (testicular deficiency in hormone production).
• Drugs, alcohol, smoking, medications.
• Pituitary failure to produce gonadotropins (FSH/LH).

Testicular (low quantity / poor-quality semen)

• Cryptorchidism, hydrocele, mumps.
• Genetic defects on Y chromosome.
• Testicular cancer.
• Klinefelter syndrome (47,XXY) — small firm testes, gynecomastia, infertility.
• Varicocele — ↑ scrotal temperature → impaired spermatogenesis.

Post-testicular (defects after sperm production)

• Vas deferens obstruction / agenesis (CFTR mutation in CF).
• Prostatitis.
• Retrograde ejaculation, ejaculatory duct obstruction.

7. Summary Table

Condition	Cause / hallmark	Sequelae
Acute epididymitis	Young: C. trachomatis / N. gonorrhoeae; Older: E. coli	Scrotal pain, ischemia
Mumps orchitis	1 wk after parotitis	Atrophy + sterility
TB orchitis	Begins in epididymis; caseating granulomas	Granulomatous orchitis
Syphilis	Tertiary = gumma, obliterative endarteritis	Sterility
Cryptorchidism	Failure of descent; 10 % bilateral	3–5× ↑ seminoma, sterility
Klinefelter (47,XXY)	Small firm testes	Infertility, gynecomastia

💡 High-yield: Epididymitis = #1 cause of acute scrotal pain; young = Chlamydia/gonorrhea, older = E. coli. Mumps orchitis = 1 wk after parotitis → atrophy + sterility. TB = begins in epididymis → caseating granulomas. Syphilis tertiary = gumma + obliterative endarteritis. Cryptorchidism = undescended testes; 10 % bilateral; 3–5× ↑ seminoma risk; sterility; orchiopexy before puberty reduces both risks. Infertility causes: pre-testicular (hormonal), testicular (Klinefelter, varicocele, cryptorchidism), post-testicular (vas obstruction/CF).