What does a small (< pea‑size) nodule beneath the left testicle that moves with the testis represent, and what evaluation and management are recommended?

Evaluation and Management of a Small Mobile Nodule Beneath the Left Testicle

You need a scrotal ultrasound with Doppler immediately to characterize this nodule, as any solid intratesticular mass must be managed as potentially malignant until proven otherwise. 1

Initial Diagnostic Approach

The key first step is determining whether this nodule is intratesticular (within the testicle itself) versus extratesticular (outside the testicle, such as epididymal or paratesticular). This distinction fundamentally changes management:

Scrotal Ultrasound Findings Will Guide Next Steps:

If the nodule is intratesticular and solid:

• Any solid intratesticular mass should be managed as malignant neoplasm until proven otherwise 1
• Obtain serum tumor markers (AFP, hCG, LDH) before any intervention 1
• A hypoechoic mass with vascular flow on Doppler is highly suggestive of malignancy 1

If the nodule is extratesticular:

• These are usually benign (spermatocele, epididymal cyst, paratesticular fibrous pseudotumor)
• May require only observation or follow-up imaging
• The mobile nature you describe suggests it could be extratesticular

Size-Based Risk Stratification

Since you describe this as "less than pea-size" (likely <5-10mm), this is important:

• 50-80% of non-palpable masses <2 cm are benign 1
• Masses <2 cm with normal tumor markers have 61.9% likelihood of being non-germ cell tumors 2
• However, size alone cannot exclude malignancy - all 6 malignant lesions in one surveillance study were >5mm and showed vascularity 3

Management Algorithm Based on Ultrasound Results:

For Small Intratesticular Masses (<2 cm) with Normal Tumor Markers:

Three acceptable options exist 1:

1. Repeat ultrasound in 6-8 weeks with clinical follow-up 1
2. Radical inguinal orchiectomy (definitive diagnosis and treatment)
3. Testis-sparing surgery with intraoperative frozen section at experienced centers 1

The surveillance option is reasonable if:

• Tumor markers (AFP, hCG, LDH) are completely normal
• The mass shows no concerning features (no increased vascularity, homogeneous appearance)
• You can commit to close follow-up
• The contralateral testicle is normal

Critical Red Flags Requiring Immediate Surgical Exploration:

• Any elevation of tumor markers
• Vascular flow within the nodule on Doppler
• Growth on repeat imaging
• Heterogeneous or irregular appearance
• Patient age 20-40 years (peak testicular cancer age)

Common Pitfalls to Avoid:

1. Never perform scrotal biopsy or scrotal approach surgery - this violates lymphatic drainage and increases local recurrence risk 4
2. Don't skip tumor markers - they must be drawn before any intervention, as orchiectomy will eliminate the source 1
3. Don't assume mobility means benign - while extratesticular lesions are often mobile, small intratesticular tumors can also appear mobile
4. Don't use MRI as initial evaluation - ultrasound is the appropriate first imaging modality 1

Practical Next Steps:

1. Schedule scrotal ultrasound with Doppler within days (not weeks)
2. If ultrasound shows solid intratesticular mass: obtain tumor markers same day
3. If markers normal and mass <2 cm: discuss surveillance vs. surgery options with urology
4. If any concerning features: proceed directly to urologic evaluation for surgical planning

The mobile nature you describe is somewhat reassuring for an extratesticular process, but only ultrasound can definitively determine location and characteristics. Given testicular cancer's excellent cure rates when caught early (>95% 5-year survival for stage I disease 5), prompt evaluation is essential even though most small nodules prove benign.