What is the appropriate workup for a patient with intermittent swelling of the right testicle?

Workup for Intermittent Swelling in Right Testicle

Begin with scrotal ultrasound with Doppler as the essential first-line diagnostic test, combined with targeted history and physical examination to differentiate between intermittent testicular torsion (a surgical emergency requiring prophylactic bilateral orchiopexy) and chronic epididymitis (the most common cause of recurrent scrotal symptoms in adults). 1, 2, 3

Initial Clinical Assessment

Key Historical Features to Elicit

• Timing and pattern of swelling episodes: Intermittent testicular torsion presents with recurrent episodes of acute pain that spontaneously resolve (due to spontaneous detorsion), while chronic epididymitis typically has gradual onset with persistent or fluctuating symptoms 2, 3

• Pain characteristics: Abrupt, severe pain suggests torsion, whereas gradual onset points toward epididymitis 2

• Associated symptoms: Nausea and vomiting are common with torsion but rare with epididymitis 4

• Risk factors for epididymitis: Sexual activity, urinary tract symptoms, or history of urethritis suggest infectious etiology 2

Physical Examination Findings

• Testicular position and cremasteric reflex: Absent cremasteric reflex and high-riding testicle suggest torsion 2

• Prehn sign: Pain relief with testicular elevation suggests epididymitis, while persistent pain indicates torsion 2

• Epididymal examination: Isolated epididymal tenderness and enlargement favor epididymitis 3

• "Blue dot sign": Visible through scrotal skin in torsion of testicular appendage (though only present in 21% of cases) 2

Diagnostic Imaging Protocol

Duplex Doppler Ultrasound (First-Line Study)

This is the imaging modality of choice with sensitivity of 69-96.8% and specificity of 87-100% for testicular torsion. 1, 2, 3

The ultrasound examination must include:

• Grayscale assessment: Look for testicular homogeneity, size changes, the pathognomonic "whirlpool sign" of twisted spermatic cord (96% sensitivity), and scrotal wall thickening 2, 3

• Color and Power Doppler evaluation: Compare testicular perfusion bilaterally, using the contralateral testicle as internal control; Power Doppler is particularly useful for detecting low-flow states 2, 3

• Spectral Doppler analysis: Assess for diminished arterial velocity, decreased or absent diastolic flow, increased resistive index, or reversed diastolic flow 2

• Epididymal evaluation: Check for enlargement or increased vascularity suggesting epididymitis 3

Critical Imaging Pitfalls to Avoid

• False-negative Doppler occurs in up to 30% of cases, particularly with partial torsion where arterial flow may persist because venous obstruction occurs first 2

• Spontaneous detorsion can result in normal-appearing ultrasound despite intermittent torsion 2

• Subacute torsion (>8 hours) may show misleading findings mimicking tumor or epididymitis, including inhomogeneous testicle with alternating hypo/hyperechoic areas 5

Laboratory Studies

• Urinalysis and urine culture: Obtain if epididymal enlargement or increased vascularity is found on ultrasound 3

• STI testing: Consider if risk factors present (age <35 years, sexual activity) 3

• Serum tumor markers (AFP, β-HCG, LDH): Mandatory prior to any surgical intervention if solid mass or complex hydrocele identified, as any hydrocele in adults requires exclusion of underlying testicular tumor 3

Differential Diagnosis and Management Algorithm

If Ultrasound Shows Normal Testicular Perfusion with Epididymal Changes

• Diagnosis: Chronic epididymitis (most common cause of scrotal pain in adults) 3

• Management: Empiric antibiotic therapy combined with NSAIDs, scrotal elevation, and supportive care 3

• Follow-up: If symptoms persist despite treatment, consider repeat imaging in 6-8 weeks 2

If Ultrasound is Normal but Clinical Suspicion for Intermittent Torsion Remains High

This is the critical scenario for intermittent swelling. The "bell-clapper" deformity (abnormal horizontal lie of testicle) is found in 82% of patients with intermittent testicular torsion and predisposes to recurrent episodes. 3

• Management: Immediate urology referral for consideration of bilateral prophylactic orchiopexy to prevent complete torsion and testicular loss 3

• Rationale: Even with normal imaging, the history of intermittent symptoms warrants surgical intervention because complete torsion can occur at any time, and testicular viability is compromised if not treated within 6-8 hours 2, 3

If Ultrasound Shows Decreased or Absent Testicular Flow

• Diagnosis: Acute testicular torsion (surgical emergency) 2

• Management: Immediate urological consultation and surgical exploration within 6-8 hours of symptom onset; bilateral orchiopexy is performed to prevent contralateral torsion 2, 3

If Ultrasound Shows Wedge-Shaped Avascular Area

• Diagnosis: Segmental testicular infarction 2, 3

• Management: Urology consultation; may be managed conservatively with close follow-up 2

Key Clinical Pearls

• Never delay surgical exploration based solely on normal ultrasound when clinical suspicion for torsion is high, as imaging sensitivity is imperfect and testicular salvage rates decline rapidly after 6-8 hours 2, 5

• Intermittent symptoms with spontaneous resolution are highly suggestive of intermittent torsion and warrant prophylactic bilateral orchiopexy even with normal imaging 3

• Normal urinalysis does not exclude either torsion or epididymitis 2

• Any solid mass or complex hydrocele requires tumor marker evaluation and urology referral before surgical intervention 3