What causes testicular atrophy?

Causes of Testicular Atrophy

Testicular atrophy is primarily caused by ischemia, hormonal imbalances, trauma, infections, cryptorchidism, medications, and cancer treatments. Understanding these causes is essential for proper diagnosis and management of this condition that can significantly impact fertility and quality of life.

Common Causes of Testicular Atrophy

1. Vascular Issues and Ischemia

• Testicular torsion: Complete or partial twisting of the spermatic cord leading to compromised blood flow 1
  • The "whirlpool sign" on ultrasound is the most specific sign of torsion 1
  • Salvage rate depends on degree of torsion and duration of ischemia 1
• Varicocele: Enlargement of veins within the scrotum can lead to progressive atrophy if untreated 2

2. Trauma and Surgery

• Blunt scrotal trauma: Can cause testicular atrophy in up to 50% of patients 3
• Surgical complications:
  • Inguinal hernioplasty can cause testicular atrophy due to thrombosis of spermatic cord veins from surgical dissection 4
  • Post-orchiopexy atrophy, especially in high undescended testes 5

3. Developmental Issues

• Cryptorchidism (undescended testes):
  • If left untreated beyond 18 months of age, leads to progressive testicular atrophy 2
  • Some boys lack germ cells after 15-18 months of age 2
  • About 40% of boys with bilateral cryptorchidism have no germ cells in testicular biopsy by 8-11 years 2

4. Infections

• Epididymo-orchitis:
  • Inflammation that can spread from epididymis to testis if untreated 6
  • However, with adequate antibiotic treatment, there is no evidence for testicular atrophy 6
  • About 40% of patients develop post-inflammatory subfertility 6

5. Cancer and Cancer Treatments

• Testicular cancer: Can directly cause atrophy 2
• Radiation therapy and chemotherapy: Gonadotoxic treatments can lead to testicular damage 2

6. Hormonal Factors

• Estrogen therapy:
  • Can cause testicular atrophy with markedly reduced spermatogenesis after only 21 days 7
  • Long-term treatment results in paucity of germ cells, vacuolation of Sertoli cells, and reduction in Leydig cells 7
• Exogenous testosterone: Suppresses spermatogenesis through negative feedback to the hypothalamus and pituitary 2

7. Lifestyle Factors

• Obesity: Associated with reduced testicular function 2
• Excessive alcohol consumption: Associated with lower semen volume and potentially testicular damage 2
• Smoking: Associated with reduced fertility and potential testicular damage 2

Diagnosis of Testicular Atrophy

Clinical Evaluation

• Physical examination to assess testicular size and consistency
• Evaluation for risk factors including history of trauma, surgery, or infection

Imaging

• Ultrasound with Doppler: First-line imaging modality for scrotal evaluation 1
  • Allows assessment of testicular size, echotexture, and blood flow
  • Can differentiate between various causes of testicular pathology

Laboratory Tests

• Hormonal evaluation: Measurement of testosterone, FSH, and LH levels 2
  • FSH levels >7.5 IU/L indicate five to thirteen times higher risk of abnormal semen quality 2
• Semen analysis: Essential to assess impact on fertility 2

Prevention and Management

Prevention

• Early treatment of cryptorchidism (before 18 months of age) 2
• Prompt diagnosis and treatment of testicular torsion 1
• Sperm banking before gonadotoxic treatments 2
• Avoiding testosterone replacement in men desiring fertility 2

Lifestyle Modifications

• Weight loss for overweight individuals 2
• Smoking cessation 2
• Moderate alcohol consumption 2
• Avoiding excessive heat exposure to testes 2

Medical and Surgical Interventions

• Treatment of underlying causes (infection, varicocele, etc.)
• Hormonal therapy when appropriate:
  • hCG and FSH injections for hypogonadotropic hypogonadism 2
  • Selective estrogen receptor modulators for idiopathic oligospermia 2
  • Aromatase inhibitors for low testosterone 2

Conclusion

Testicular atrophy results from multiple potential causes, with ischemia, developmental issues, and trauma being the most common. Early identification and treatment of underlying causes is crucial to prevent progressive atrophy and preserve fertility. Regular testicular self-examination and prompt medical attention for any testicular pain or swelling are important preventive measures.