What are the possible causes and treatments for a painless swollen testicle in a patient with no other symptoms?

Painless Swollen Testicle: Evaluation and Management

A painless swollen testicle in an adult male should be considered testicular cancer until proven otherwise, requiring urgent testicular ultrasound and measurement of serum tumor markers (AFP, β-HCG, LDH) before any intervention. 1

Immediate Diagnostic Workup

Obtain high-frequency (>10 MHz) testicular ultrasound with Doppler immediately to distinguish between intra-testicular and extra-testicular masses, as approximately 90% of intra-testicular masses are malignant while extra-testicular masses are typically benign. 1, 2

Key Ultrasound Findings to Assess:

• Presence and location of solid mass (intra- vs extra-testicular) 1, 2
• Characteristics of any fluid collection (simple vs complex hydrocele) 3, 4
• Contralateral testis evaluation for synchronous tumors or microcalcifications 1
• Testicular vascularity to exclude torsion 1, 5

Mandatory Laboratory Studies:

• Serum tumor markers before any surgical intervention: AFP, β-HCG, and LDH 1
• These markers support diagnosis, provide prognostic information, and guide treatment even if the mass appears benign on imaging 1

Critical Differential Diagnoses

Testicular Cancer (Most Important to Exclude)

A painless solid testicular mass is pathognomonic for testicular tumor, though patients more commonly present with testicular discomfort or swelling that may initially suggest benign conditions. 1

• Over 90% of patients with germ cell tumors are cured, but delay in diagnosis correlates with higher stage at presentation 1
• Any palpable intra-testicular abnormality warrants urgent evaluation even after a trial of antibiotics for presumed infection 1
• Testicular cancer commonly presents as unilateral painless mass discovered incidentally 6, 7

Hydrocele (Common Benign Cause)

Hydrocele is the most common benign cause of painless scrotal enlargement, but can mask underlying testicular tumors, making physical examination unreliable. 3, 4, 2

• Any hydrocele in a young adult (age 20-40) requires urgent ultrasound to exclude underlying malignancy 2
• "Complex hydrocele" on ultrasound should raise suspicion for testicular tumor with irregular septations or solid components 4
• Simple hydroceles appear as anechoic fluid collections between tunica vaginalis layers 2, 7

Epididymal Cyst/Spermatocele

Epididymal cysts are the most common finding in patients referred for testicular lumps (27% in one study), appearing as extra-testicular cystic masses. 2

• These are benign and typically require no treatment 6, 7
• Ultrasound easily distinguishes these from intra-testicular pathology 2

Varicocele

Varicoceles present as "bag of worms" sensation, typically on the left side, and may be associated with impaired fertility. 6, 7

• Generally asymptomatic but may cause dull aching discomfort 6
• Ultrasound shows dilated pampiniform plexus veins >3mm 7

Management Algorithm

If Intra-testicular Mass Identified:

1. Obtain complete blood count, creatinine, electrolytes, liver enzymes, and chest radiograph 1
2. Measure serum tumor markers (AFP, β-HCG, LDH) before orchiectomy 1
3. Discuss sperm banking before any therapeutic intervention that may compromise fertility 1
4. Proceed with radical inguinal orchiectomy as primary treatment for suspected testicular cancer 1
5. Never perform scrotal approach, as this is associated with higher local recurrence rates 1

If Extra-testicular Mass or Simple Hydrocele:

1. Confirm benign appearance on ultrasound with normal testicular parenchyma 2, 7
2. Verify normal serum tumor markers to exclude occult malignancy 1
3. Provide reassurance and observation for asymptomatic benign masses 6, 7
4. Consider surgical intervention only if symptomatic or patient preference 7

If Ultrasound Shows Complex or Uncertain Findings:

1. Obtain serum tumor markers immediately 1
2. Refer urgently to urology for consideration of surgical exploration 2
3. Do not delay definitive diagnosis with prolonged observation 1

Common Pitfalls to Avoid

Never assume a hydrocele is benign without ultrasound confirmation that the underlying testis is normal, as hydroceles can mask testicular tumors and delay diagnosis of metastatic disease. 3, 4

Do not give prolonged trials of antibiotics for presumed epididymitis when a discrete testicular mass is palpable—persistent swelling or any palpable abnormality warrants immediate ultrasound. 1

Avoid testicular biopsy through scrotal approach for suspected malignancy, as radical inguinal orchiectomy is the appropriate diagnostic and therapeutic procedure. 1

Do not reassure young men (age 20-40) with hydroceles without urgent ultrasound evaluation, as this age group has highest testicular cancer incidence. 2

Remember that normal tumor markers do not exclude testicular cancer, as they have low sensitivity especially in pure seminomas—ultrasound findings take precedence. 1