What is the diagnosis and treatment for a male of reproductive age with no significant medical history experiencing left groin pain radiating to the back with testicular pain at rest?

Testicular Torsion Until Proven Otherwise

This presentation of left groin pain radiating to the back with testicular pain at rest in a reproductive-age male is testicular torsion until proven otherwise and requires immediate urological consultation and urgent Doppler ultrasound—do not delay for imaging if clinical suspicion is high, as testicular viability is lost after 6-8 hours. 1, 2

Immediate Action Required

• Obtain immediate urological consultation while simultaneously ordering urgent Doppler ultrasound of the scrotum 1, 3
• The 6-8 hour window from symptom onset is critical—surgical salvage rates drop precipitously after this timeframe, with permanent ischemic damage occurring 1, 2
• Do not wait for imaging results if clinical suspicion is high based on physical examination findings 3

Key Clinical Features to Assess Immediately

Distinguishing Testicular Torsion (Surgical Emergency)

• Abrupt onset of severe scrotal/testicular pain developing within minutes 1, 2
• Negative Prehn sign—pain is NOT relieved when elevating the testicle (this distinguishes torsion from epididymitis) 1, 2
• Nausea and vomiting commonly accompany the pain 2
• Firm, tender testicle on examination 3
• Pain radiating to groin and lower back is consistent with torsion 1, 4

Alternative Diagnosis: Epididymitis (More Common in Adults)

• Gradual onset of pain over hours to days 1, 3
• Positive Prehn sign—pain IS relieved with testicular elevation 3
• May have urinary symptoms or abnormal urinalysis 1
• However, normal urinalysis does NOT exclude torsion 1

Diagnostic Imaging Protocol

Duplex Doppler Ultrasound Findings

• For testicular torsion: Decreased or absent blood flow to affected testicle, "whirlpool sign" of twisted spermatic cord (96% sensitivity), enlarged heterogeneous hypoechoic testis, ipsilateral hydrocele 1, 2
• For epididymitis: Enlarged epididymis with INCREASED blood flow on color Doppler, scrotal wall thickening 1, 3
• Critical caveat: Ultrasound sensitivity ranges 69-96.8%—false negatives occur in 30% of cases, particularly with partial torsion or early presentation 1
• Always compare to the contralateral asymptomatic testicle as internal control 1

Management Algorithm

High Clinical Suspicion (Acute onset, negative Prehn sign, severe pain)

1. Immediate urological consultation for surgical exploration without waiting for imaging 1, 3
2. Proceed directly to operating room for detorsion and bilateral orchiopexy 1

Intermediate Clinical Suspicion

1. Urgent Doppler ultrasound (grayscale + color Doppler + power Doppler) 1
2. If decreased/absent flow → immediate surgical exploration 1
3. If normal flow but high clinical suspicion persists → still proceed to surgical exploration (do not be falsely reassured) 1

If Epididymitis Confirmed

• Bed rest, scrotal elevation, analgesics 1
• Antibiotic therapy based on age and risk factors 1
• However, do not start antibiotics empirically if torsion cannot be excluded—this delays correct diagnosis 3

Critical Pitfalls to Avoid

• Do not be reassured by normal urinalysis—this does not exclude torsion 1
• Do not delay for imaging when clinical presentation strongly suggests torsion—the trauma of examination or patient movement can complete a partial torsion 3
• Partial torsion is the most dangerous diagnostic trap—arterial flow may persist on Doppler because venous obstruction occurs first, leading to false-negative ultrasound 1
• Age is not protective—while torsion has bimodal distribution (neonates and postpubertal boys), it occurs in reproductive-age adults 1, 2
• The history of pain radiating to back does not exclude torsion and is actually consistent with referred pain patterns 4

Additional Differential Considerations (Lower Priority)

• Incarcerated inguinal hernia with bowel contents—can present with groin and testicular pain, but typically has palpable groin mass 5
• Renal colic—can cause referred testicular pain but usually has flank pain predominance 4
• Varicocele—causes chronic dull aching pain, not acute presentation at rest 6

Bottom line: Treat this as testicular torsion with immediate urological consultation and urgent surgical exploration if clinical examination suggests acute onset with negative Prehn sign—imaging should not delay definitive management. 1, 3