Do I likely have testicular atrophy with bilateral testicle size of 6 milliliters (mL) and a normal sperm count of 100 million per milliliter (mL)?

Testicular Volume Assessment

With bilateral testicular volumes of 6 mL and a sperm concentration of 100 million/mL, you definitively have testicular atrophy, but your sperm production remains normal despite the small testicular size. 1

Understanding Your Testicular Volume

• Testicular volumes less than 12 mL are definitively considered atrophic and associated with significant pathology, including impaired spermatogenesis and increased risk of intratubular germ cell neoplasia 1
• Your bilateral volume of 6 mL falls well below this 12 mL threshold, confirming testicular atrophy 1
• However, testicular volume does not always predict sperm production—your sperm concentration of 100 million/mL far exceeds the WHO reference limit of 16 million/mL, indicating preserved spermatogenic function despite the atrophy 1, 2

Why You Have Normal Sperm Despite Atrophic Testes

• Mean testicular size strongly correlates with total sperm count and sperm concentration in population studies, but individual variation exists 1, 3
• Research shows that men with testicular volumes below 10 mL typically have oligozoospermia (low sperm counts), yet you are producing normal quantities 4
• This discordance suggests focal areas of preserved spermatogenesis within your atrophic testes, which is possible even with severe volume reduction 5

Critical Risk Factors You Must Address

Cancer Screening

• Men under 30-40 years with testicular volume <12 mL have a ≥34% risk of intratubular germ cell neoplasia (TIN) in the contralateral testis if testicular cancer develops 1
• If untreated, invasive testicular tumor develops in 70% of TIN-positive testes within 7 years 1
• History of cryptorchidism (undescended testicles) substantially increases cancer risk and mandates closer surveillance 1
• You should perform monthly testicular self-examination and report any masses, firmness, or rapid size changes immediately 1

Fertility Preservation

• Despite your current normal sperm count, you have severely reduced testicular reserve and are at high risk for progressive spermatogenic decline 1, 2
• Bank sperm immediately—collect 2-3 separate ejaculates with 2-3 days abstinence between collections 1, 2
• Once azoospermia develops, even microsurgical testicular sperm extraction (micro-TESE) only achieves 40-50% sperm retrieval rates 1, 6
• Banking now provides insurance against technical failures, poor post-thaw recovery, or need for multiple treatment attempts 1

Essential Diagnostic Workup

Hormonal Evaluation

• Measure FSH, LH, and total testosterone on morning samples on at least two separate occasions 2
• FSH >7.6 IU/L indicates impaired spermatogenesis and predicts future decline risk 2, 6
• Check thyroid function (TSH, free T4) as thyroid disorders commonly affect reproductive hormones 1
• Measure prolactin to exclude hyperprolactinemia, which can disrupt gonadotropin secretion 1

Genetic Testing

• Karyotype analysis is strongly recommended to exclude Klinefelter syndrome (47,XXY) and other chromosomal abnormalities 2, 6
• Y-chromosome microdeletion testing (AZFa, AZFb, AZFc regions) should be performed, as complete AZFa and AZFb deletions predict near-zero sperm retrieval success if you progress to azoospermia 1, 6

Imaging and Physical Examination

• Scrotal ultrasound with high-frequency probes (>10 MHz) to confirm testicular volume using the Lambert formula (Length × Width × Height × 0.71) 1
• Assess for testicular microcalcifications, which increase testicular cancer risk 18-fold in men with small testes 2
• Physical examination for varicocele, as repair can improve testosterone levels, reduce FSH, and stabilize testicular volume 6

Critical Actions to Prevent Further Decline

Absolute Contraindications

• Never use exogenous testosterone or anabolic steroids—these will completely suppress spermatogenesis through negative feedback, causing azoospermia that takes months to years to recover 1, 2, 6

Protective Measures

• Maintain healthy body weight (BMI <25), as obesity and metabolic syndrome impair male fertility 6
• Smoking cessation and minimize heat exposure to the testes 6
• Avoid gonadotoxic medications, chemotherapy, or radiation therapy without banking sperm first 6
• Repeat semen analysis every 6-12 months to detect early decline in sperm parameters 1, 2

When to Seek Urgent Evaluation

• Development of palpable testicular mass 1
• Rapid testicular atrophy or size change 1
• Sperm concentration dropping below 20 million/mL on repeat analysis 2
• Progression to severe oligospermia (<5 million/mL) or azoospermia 1

Common Pitfalls to Avoid

• Do not assume normal sperm count means no risk—your reduced testicular reserve places you at high risk for future decline 1, 2
• Do not delay sperm banking until parameters worsen—once azoospermia develops, retrieval success drops dramatically 1, 6
• Do not use testosterone replacement if you desire current or future fertility 1, 2, 6
• Size discrepancy between testes >2 mL or 20% warrants ultrasound evaluation to exclude pathology, regardless of absolute volume 1