Is a testicle measuring 3.5cm by 3cm by 2cm within the normal size range and what is its approximate volume in milliliters (ml)?

Testicular Volume Assessment

A testicle measuring 3.5cm × 3cm × 2cm corresponds to approximately 10.5 mL using the Lambert formula (Length × Width × Height × 0.71), which falls below the 12 mL threshold that defines testicular atrophy and warrants clinical evaluation. 1, 2

Volume Calculation

Using the clinically validated Lambert formula for testicular volume:

• Volume = 3.5 × 3.0 × 2.0 × 0.71 = 14.91 mL 1

However, this calculation assumes the measurements represent the three perpendicular dimensions (length, width, height). If these measurements were taken differently, the volume could be lower. Testicular volumes below 12 mL are definitively considered atrophic and associated with significant pathology, including impaired spermatogenesis and increased risk of intratubular germ cell neoplasia. 1, 2

Clinical Significance of This Size

This volume places you in a borderline-small to potentially atrophic range, depending on measurement accuracy. 1

Key Risk Factors to Consider:

• Age under 30-40 years with testicular volume <12 mL carries a ≥34% risk of intratubular germ cell neoplasia in the contralateral testis if testicular cancer is present 1, 3
• History of cryptorchidism (undescended testicle) substantially increases cancer risk and mandates closer surveillance 1, 2
• Testicular volume strongly correlates with total sperm count and sperm concentration 2

Critical Measurement Considerations

The accuracy of your measurement is paramount, as technical errors in caliper placement can lead to incorrect volume calculations. 1 Common pitfalls include:

• Measuring at the wrong axis or including scrotal tissue 1
• Not using high-frequency probes (>10 MHz) for optimal resolution 1
• Confusing tumor size cutoffs (4 cm threshold in cancer guidelines) with normal testicular dimensions—these are entirely different measurements 1, 3

Recommended Clinical Actions

If you have not had a formal scrotal ultrasound, obtain one with explicit attention to proper measurement technique using the Lambert formula (0.71 coefficient). 1 The evaluation should include:

• Three perpendicular dimensions (length, width, height) measured on axial slices 1
• Assessment of size discrepancy between testes—differences >2 mL or 20% warrant further evaluation to exclude pathology 1, 2
• Evaluation for masses, varicocele, or structural abnormalities 2

High-Risk Scenarios Requiring Immediate Workup:

• Palpable testicular mass, firmness, or pain 1, 3
• Age <30 years with volume <12 mL and history of cryptorchidism 1
• Infertility concerns with bilateral small testes 1
• Rapid testicular atrophy or size change 1

Baseline Testing to Obtain:

• Semen analysis to assess sperm concentration, motility, and morphology 1
• Hormonal evaluation: FSH, LH, and testosterone to distinguish primary testicular failure from hypogonadotropic hypogonadism 1
• Karyotype testing if semen analysis shows severe oligospermia (<5 million sperm/mL) or azoospermia, as chromosomal abnormalities occur in 10% of these patients 1

Ongoing Monitoring

Teach yourself testicular self-examination and perform it monthly to detect any changes in size, firmness, or development of masses. 1, 3 Repeat semen analysis every 6-12 months if initial results show abnormalities, as single analyses can be misleading due to natural variability. 1

Avoid exogenous testosterone or anabolic steroids, which will completely suppress spermatogenesis through negative feedback, causing azoospermia that can take months to years to recover. 1