What is the most likely diagnosis for a patient presenting with a 2-day history of right-sided scrotal pain, a right testis with vertical orientation, tenderness around the superior pole, and a red, edematous scrotum?

Diagnosis: Torsion of a Testicular Appendage (Answer D)

The most likely diagnosis is torsion of a testicular appendage, given the 2-day symptom duration, localized tenderness at the superior pole, and the patient's ability to tolerate symptoms for 48 hours without complete testicular compromise. 1

Key Diagnostic Reasoning

Why Not Testicular Torsion (Answer A)?

While testicular torsion remains in the differential, several features make it less likely:

• Symptom duration tolerance: True testicular torsion typically presents with abrupt onset of severe scrotal pain that would be difficult to tolerate for 2 days without seeking immediate care 1, 2
• Localized superior pole tenderness: Testicular torsion causes diffuse testicular pain rather than focal superior pole tenderness 1
• Vertical testicular orientation: While this finding suggests abnormal anatomy (bell-clapper deformity), it can be present without active torsion 2
• Critical time window: If this were complete testicular torsion, permanent ischemic damage would have already occurred beyond the 6-8 hour window, and the testis would likely be non-viable by 48 hours 1, 2, 3

Why Torsion of Testicular Appendage (Answer D) is Most Likely:

• Age and presentation: Torsion of testicular appendage is the most common cause of testicular pain in prepubertal boys and can occur in adolescents 1
• Focal superior pole tenderness: This is the classic location for appendix testis torsion, which sits at the upper pole of the testis 1
• Gradual onset tolerability: Unlike testicular torsion, appendiceal torsion causes pain that develops over 1-2 days and is more tolerable 1
• Scrotal edema and erythema: These findings occur with appendiceal torsion due to local inflammation 1
• The "blue dot sign": While only present in 21% of cases, when visible it is pathognomonic for appendiceal torsion 1

Why Not Epididymo-orchitis (Answer B)?

• Age consideration: Epididymo-orchitis is overwhelmingly the most common cause of testicular pain in adults but less common in adolescents 1
• Gradual onset pattern: While epididymitis does have gradual onset (consistent with 2-day history), the focal superior pole tenderness is more characteristic of appendiceal torsion than diffuse epididymal inflammation 1
• Urinalysis findings: Epididymitis often (though not always) shows abnormal urinalysis, which should be checked 1

Why Not Incarcerated Inguinal Hernia (Answer C)?

• This would present with a palpable mass in the inguinal canal or scrotum, bowel sounds in the scrotum, and symptoms of bowel obstruction—none of which are described 3

Critical Management Algorithm

Despite the most likely diagnosis being appendiceal torsion, testicular torsion MUST be definitively ruled out:

1. Immediate Doppler ultrasound is mandatory to assess testicular perfusion 1, 3

   • Look for normal or increased blood flow (rules out complete torsion)
   • Identify the "whirlpool sign" if torsion present 1
   • Assess for enlarged heterogeneous testis suggesting ischemia 1

2. If ultrasound shows decreased/absent testicular blood flow: Immediate urological consultation for surgical exploration within 6-8 hours 1, 2

3. If ultrasound confirms normal testicular perfusion: Diagnosis of appendiceal torsion can be made clinically, and management is conservative with NSAIDs and scrotal support 1

Common Pitfalls to Avoid

• Never assume epididymitis in young patients: The diagnosis should be made with extreme caution in prepubertal and adolescent males 3
• False-negative Doppler studies occur in 30% of partial torsion cases: If clinical suspicion remains high despite normal Doppler, surgical exploration is still warranted 1
• The cremasteric reflex: An absent ipsilateral cremasteric reflex is the most accurate clinical sign of testicular torsion and should always be assessed 3
• Don't delay imaging: While appendiceal torsion is most likely, any acute scrotal pain must be treated as potential surgical emergency until torsion is excluded 1, 2

The 2-day symptom duration with focal superior pole tenderness strongly favors appendiceal torsion, but urgent Doppler ultrasound is non-negotiable to definitively exclude testicular torsion before committing to conservative management. 1, 3