What is the diagnosis and treatment for testicle atrophy?

Diagnosis and Treatment of Testicular Atrophy

Defining Testicular Atrophy

Testicular atrophy is definitively diagnosed when testicular volume falls below 12 mL, not by volume measurement alone but through comprehensive clinical evaluation including history, physical examination findings, hormonal assessment, and ultrasound characteristics. 1

The statement "volume alone does not diagnose testicular atrophy" is correct because:

• Volume <12 mL is the threshold that defines atrophy, but this measurement must be interpreted within clinical context including patient age, fertility history, presence of cryptorchidism, and associated symptoms 1
• Measurement technique matters critically—the Lambert formula (Length × Width × Height × 0.71) should be used rather than the traditional ellipsoid formula (0.52 coefficient), which systematically underestimates volume and may lead to inappropriate classification 1
• Size discrepancy between testes >2 mL or 20% warrants further evaluation regardless of absolute volume, as asymmetry may indicate underlying pathology 1

Diagnostic Approach

Clinical History and Physical Examination

Obtain detailed history focusing on:

• History of cryptorchidism (undescended testicles), which substantially increases both atrophy risk and testicular cancer risk 1
• Infertility concerns, as testicular volume strongly correlates with total sperm count and sperm concentration 1
• Family history of testicular cancer and prior testicular pathology 1
• Age at presentation, as men under 30-40 years with volume <12 mL have significantly elevated cancer risk 1

Imaging Studies

Scrotal ultrasound with high-frequency probes (>10 MHz) is the mandatory first-line imaging modality to:

• Confirm testicular volume using standardized three-dimensional measurements (length, width, height) 1
• Assess echogenicity patterns—atrophic testes may show heterogeneous echogenicity (post-torsion, post-orchitis, trauma) or homogeneous hypoechogenicity (cryptorchidism, inguinal hernia) 2
• Identify structural abnormalities including masses, varicocele, or epididymal pathology 1
• Evaluate the contralateral testis for comparison and to exclude bilateral pathology 1

Laboratory Evaluation

Hormonal assessment is essential and should include:

• Serum FSH, LH, and total testosterone to distinguish primary testicular failure from secondary hypogonadism 1
• Tumor markers (AFP, β-HCG, LDH) if testicular cancer is suspected, obtained before any surgical intervention 3, 4
• Semen analysis if fertility is a concern, as volumes <12 mL are associated with impaired spermatogenesis 1
• Karyotype testing if severe oligospermia (<5 million sperm/mL) or azoospermia is present, as chromosomal abnormalities occur in 10% of these patients 1

Etiology-Specific Considerations

Common Causes of Testicular Atrophy

• Cryptorchidism—undescended testes show homogeneous hypoechogenicity on ultrasound and require orchiopexy by 18 months of age to maximize fertility potential 2, 5
• Testicular torsion—results in heterogeneous echogenicity and requires immediate surgical exploration within 6 hours for >90% salvage rates 2
• Mumps orchitis—produces heterogeneous echogenicity and may result in permanent atrophy 2
• Varicocele—atrophic testes remain isoechoic to normal testis despite volume loss 2
• Inguinal hernia repair—testicular atrophy occurs due to thrombosis of spermatic cord veins from surgical trauma 6
• Idiopathic lymphocytic orchitis—a rare cause manifesting as progressive atrophy with chronic pain 7

Cancer Risk Stratification

High-Risk Scenarios Requiring Testicular Biopsy

Contralateral testicular biopsy is strongly indicated in the following situations:

• **Age <30 years with testicular volume <12 mL in the setting of testicular cancer**, as there is a >34% risk of testicular intraepithelial neoplasia (TIN) in the contralateral testis 3, 1
• History of cryptorchidism combined with volume <12 mL, regardless of cancer diagnosis 3, 1
• Bilateral small testes (<12 mL) with infertility in young men 1

If TIN is left untreated, invasive testicular tumor develops in 70% of cases within 7 years 1

Surveillance vs. Active Treatment for TIN

When TIN is diagnosed:

• If fertility preservation is desired: delay definitive treatment with close surveillance until fertility goals are achieved, then proceed with active treatment 3
• If fertility is not relevant: radiation therapy with 20 Gy (2 Gy fractions, 5 days/week) is the standard treatment 3
• In patients with normal contralateral testis: orchiectomy is preferred over radiation to avoid scattered radiation damage to the unaffected testis 3
• In patients receiving chemotherapy: postpone radiation treatment, as chemotherapy eradicates TIN in two-thirds of patients; re-biopsy at least 6 months post-chemotherapy to confirm TIN status 3

Treatment Strategies

Hormonal Management

After radiation treatment or in patients with documented atrophy:

• Regular monitoring of serum testosterone levels is mandatory, as radiation and atrophy may impair Leydig cell function 3
• Hormone replacement therapy should be offered to all patients with subnormal testosterone levels and clinical signs of androgen deficiency 3

Surgical Considerations

Testis-sparing surgery (TSS) may be offered in highly selected patients with:

• Masses <2 cm with equivocal ultrasound/physical exam findings and negative tumor markers 3
• Congenital, acquired, or functionally solitary testis 3
• Bilateral synchronous tumors 3

Patients considering TSS must be counseled regarding:

• Higher risk of local recurrence compared to radical orchiectomy 3
• Need for lifelong monitoring with physical examination and ultrasound 3
• Role of adjuvant radiotherapy to reduce local recurrence, which eliminates fertility 3
• Risk of progressive testicular atrophy and need for testosterone replacement 3

Fertility Preservation

Sperm cryopreservation should be discussed before any therapeutic intervention in reproductive-age men, particularly those with:

• Bilateral testicular pathology 3
• Planned chemotherapy or radiation therapy 3
• Solitary testis requiring treatment 3

Critical Pitfalls to Avoid

• Never assume small testes are benign without proper workup—volumes <12 mL mandate evaluation for TIN risk, especially in high-risk populations 1
• Never use the traditional ellipsoid formula (0.52 coefficient) for clinical decision-making, as it systematically underestimates volume 1
• Never perform scrotal biopsy or scrotal incision for suspected malignancy—only radical inguinal orchiectomy is appropriate 8
• Never delay evaluation of a testicular mass to address other urological conditions first, as delay correlates with higher stage at presentation and worse mortality 4
• Never rely on physical examination alone to exclude testicular pathology in patients with atrophy—ultrasound is mandatory 1

Long-Term Monitoring

Teach testicular self-examination to all patients with testicular atrophy, given increased cancer risk with smaller volumes 1

Routine follow-up should include:

• Annual physical examination with attention to contralateral testis 3
• Periodic testosterone monitoring in patients with bilateral atrophy or post-radiation 3
• Ultrasound surveillance if TIN surveillance strategy is chosen over definitive treatment 3