How is Appendix Testis Torsion diagnosed?

Diagnosing Appendix Testis Torsion

Doppler ultrasound of the scrotum is the definitive diagnostic test for appendix testis torsion, which should include both grayscale and color/power Doppler evaluation to assess for the characteristic findings of a twisted appendage. 1, 2

Clinical Presentation and Initial Assessment

• Appendix testis torsion typically presents with:
  • Acute onset of scrotal pain (usually less severe than testicular torsion)
  • Localized tenderness at the upper pole of the testis
  • Possible "blue dot sign" (pathognomonic but infrequently seen) 1
  • Normal urinalysis (unlike epididymitis which may show pyuria)
  • Preserved testicular blood flow (unlike testicular torsion)

Diagnostic Imaging

Ultrasound Examination

• First-line imaging modality with high sensitivity and specificity 1, 2
• Complete scrotal ultrasound should include:
  • Grayscale imaging to evaluate:
    • Testicular parenchyma
    • Epididymal enlargement
    • Presence of hydrocele
    • Scrotal wall thickening
    • Identification of the twisted appendage (appears as an enlarged, hypoechoic structure)
  • Color and power Doppler assessment to:
    • Confirm normal testicular perfusion (differentiating from testicular torsion)
    • Evaluate for hyperemia surrounding the twisted appendage
    • Demonstrate absence of blood flow within the appendage itself

Key Ultrasound Findings in Appendix Testis Torsion

• Enlarged, hypoechoic, avascular nodule at the upper pole of the testis
• Normal testicular blood flow (critical distinguishing factor from testicular torsion)
• Possible reactive hydrocele
• Possible surrounding hyperemia due to inflammation

Differential Diagnosis

The main differential diagnoses to consider include:

1. Testicular torsion

   • Requires immediate surgical intervention
   • Distinguished by absence of testicular blood flow on Doppler ultrasound
   • May present with "whirlpool sign" (twisted spermatic cord) with 96% sensitivity and 99% specificity 2

2. Epididymitis

   • More gradual onset of pain
   • Often associated with urinary symptoms and abnormal urinalysis
   • Increased blood flow to epididymis on Doppler ultrasound 1

Management Considerations

• Conservative management is typically appropriate for confirmed appendix testis torsion:

  • Rest
  • Scrotal support/elevation
  • NSAIDs for pain control
  • Follow-up in 1-2 weeks 2

• Surgical intervention is indicated when:

  • Diagnosis is uncertain and testicular torsion cannot be ruled out
  • Pain is severe or persistent despite conservative measures
  • Recurrent episodes occur 3

Important Caveats

• In pediatric patients, the TWIST (Testicular Workup for Ischemia and Suspected Torsion) score can help risk-stratify patients, but imaging remains essential for intermediate-risk cases 1, 2
• Appendix testis torsion can rarely occur simultaneously with testicular torsion, which would require surgical intervention 4
• Appendix testis torsion can occur in undescended testes, making diagnosis more challenging 5
• If high clinical suspicion for testicular torsion exists, do not delay surgical exploration for imaging 2, 6

Follow-up

• Resolution of symptoms typically occurs within 1-2 weeks with conservative management
• Persistent or worsening pain should prompt re-evaluation and consideration of surgical intervention