Is Testicular Atrophy Likely with Normal Semen Analysis and High Testosterone?
No, testicular atrophy is extremely unlikely if your semen analysis is normal and your testosterone is high, as testicular atrophy directly impairs spermatogenesis and causes measurable abnormalities on semen analysis that correlate with the degree of testicular volume reduction. 1
Why Normal Semen Analysis Rules Out Significant Testicular Atrophy
Testicular atrophy causes predictable semen abnormalities: Severe testicular atrophy (volumes ≤2 mL) is associated with non-obstructive azoospermia (complete absence of sperm) in the majority of cases, while moderate testicular atrophy (volumes <12 mL but >2 mL) typically presents with oligospermia (reduced sperm concentration). 1
Testicular size directly correlates with sperm production: Studies demonstrate that testicular size has the strongest correlation with total sperm count and sperm concentration, with both sperm quantity and quality becoming impaired in testes smaller than 14 mL. 2
Normal semen parameters indicate adequate testicular volume: Research shows that sperm output is positively correlated with testicular volume (r = 0.28, P < 0.005), meaning normal sperm counts reflect normal-sized, functional testes. 3
Hormonal Evidence Against Testicular Atrophy
FSH would be elevated with atrophy: Elevated FSH levels (>7.6 IU/L) are the hallmark hormonal finding in men with testicular atrophy, reflecting the pituitary's compensatory response to impaired spermatogenesis. 1 Your high testosterone without mention of elevated FSH suggests normal testicular function.
High testosterone indicates normal Leydig cell function: Testicular atrophy typically results in decreased testosterone production due to loss of Leydig cells. 4 Your high testosterone is inconsistent with significant testicular damage.
The combination matters: Non-obstructive azoospermia from testicular atrophy is characterized by atrophic testes AND elevated FSH (>7.6 IU/L), not high testosterone with normal semen analysis. 1
Clinical Caveats
Physical examination remains important: While your laboratory values strongly suggest normal testicular size, testicular volumes should be assessed using a Prader orchidometer or ultrasound if there is clinical concern, as volumes <12 mL are considered atrophic. 1
Testicular atrophy has multiple causes: Post-chemotherapy, radiation therapy, history of cryptorchidism, or testicular torsion can cause atrophy, but all would manifest with abnormal semen parameters. 1, 4
Varicocele does not explain your scenario: Even men with moderate left testicular atrophy from varicocele typically have abnormal semen parameters or elevated FSH if spermatogenesis is impaired. 3