What could be causing testicular atrophy with no symptoms in a male of reproductive age with a small, non-palpable left-sided varicocele (varicose vein)?

Testicular Atrophy with Small Non-Palpable Left Varicocele: Differential Diagnosis

The small, non-palpable left varicocele is unlikely to be the primary cause of your testicular atrophy, and you need comprehensive evaluation for other etiologies including hypogonadism, genetic abnormalities, prior testicular injury, and systemic conditions. 1, 2

Why the Varicocele is Probably Not the Culprit

Non-palpable (subclinical) varicoceles do not cause clinically significant testicular damage and should not be treated. 1, 2 The evidence is clear on this point:

• Treatment of subclinical varicoceles does not improve semen parameters or fertility rates, indicating they lack pathophysiological significance 2
• Routine ultrasonography to identify non-palpable varicoceles is actively discouraged by both the American Urological Association and European Association of Urology because these findings are not clinically meaningful 1, 2
• Clinical (palpable) varicoceles are present in 15% of normal males, and most never require treatment 2

Only palpable varicoceles with reflux on Valsalva maneuver are associated with testicular dysfunction and atrophy. 2 Higher grade varicoceles (Grade III with vein diameter >6mm) correlate with worse testicular parameters, but your non-palpable varicocele does not meet these criteria 2

What Else Could Be Causing Testicular Atrophy

You need evaluation for the following conditions:

Primary Hypogonadism

• Check FSH, LH, and testosterone levels immediately. 1 Elevated FSH (>7.6 IU/L) suggests primary testicular failure or spermatogenic dysfunction 1
• FSH levels in the 9-12 IU/L range indicate impaired spermatogenesis or testicular dysfunction, not varicocele effect 1

Genetic Abnormalities

• Karyotype testing and Y-chromosome microdeletion analysis (AZFa, AZFb, AZFc regions) should be obtained if sperm concentration is <5 million/ml. 1 Chromosomal abnormalities occur in approximately 4% of men with very low sperm counts 1
• Complete AZFa or AZFb deletions predict irreversible testicular dysfunction 1

Prior Testicular Trauma or Infection

• Scrotal ultrasound with Doppler can identify sequelae of prior trauma including testicular hematoma, infarct, or chronic inflammatory changes. 3 Even without recalled trauma, chronic hematomas appear as hypoechoic or anechoic areas 3
• Prior epididymo-orchitis can cause permanent testicular damage and atrophy 3

Testicular Torsion (Resolved)

• Prior intermittent or resolved torsion can cause testicular atrophy without current symptoms 3
• Ultrasound may show heterogeneous hypoechoic echotexture in the affected testis 3

Systemic Conditions

• Chronic liver disease increases SHBG levels and can affect testicular function 1
• Medications (particularly antiepileptic drugs) can increase SHBG production and affect gonadal function 1

Recommended Diagnostic Workup

Start with scrotal duplex Doppler ultrasound to:

• Confirm the varicocele is truly non-palpable and measure vein diameter 2, 4
• Assess testicular size, texture, and homogeneity bilaterally 4
• Evaluate for alternative pathology (masses, hematomas, infarcts, inflammatory changes) 3, 4
• Document testicular volume difference (>2 mL or >20% difference is significant) 1, 2

Obtain hormonal evaluation:

• FSH, LH, total testosterone, and SHBG 1
• If FSH is elevated (>7.6 IU/L), this indicates primary testicular dysfunction requiring further investigation 1

Consider genetic testing if:

• Sperm concentration is <5 million/ml 1
• FSH is significantly elevated 1

Critical Pitfall to Avoid

Do not attribute testicular atrophy to a non-palpable varicocele and pursue varicocelectomy. 1, 2 This is a common error. While palpable varicoceles can cause progressive testicular damage and atrophy in some men 5, 6, subclinical varicoceles detected only on ultrasound do not have this effect and surgery will not reverse the atrophy 1, 2

The fact that your varicocele is non-palpable means it lacks the hemodynamic significance required to cause testicular dysfunction 2. Look elsewhere for the cause of atrophy.