CC: Left flank pain… or is it?

Chief complaint: Acute left flank pain

• Start with what you actually know from triage.
• Do not diagnose the patient yet.

GU

• Nephrolithiasis / ureteral stone
• Pyelonephritis
• UTI

Male reproductive / groin

• Testicular torsion
• Epididymitis
• Incarcerated inguinal hernia

GI

• Appendicitis
• Diverticulitis
• Colitis / other bowel pathology

Musculoskeletal

• Lumbar or abdominal wall strain

Other / dangerous mimics

• Lower-lobe pneumonia
• Retroperitoneal process

Not unstable.

• No shock, respiratory distress, altered mental status, or active bleeding.
• No immediate resuscitation is required; proceed with a focused history and exam.
• Sudden severe pain still demands a time-sensitive differential even when the patient looks stable.

Do a genital / testicular exam.

• Testicular torsion can present with abdominal, groin, or flank pain.
• Do not let the triage label prevent you from examining the scrotum when the story does not fit.

Revised chief complaint: Acute unilateral testicular pain

• The chief complaint can change as better information becomes available.
• He initially presented with flank pain but on further examination he actually has testicular pain that radiates to the flank. The origin of the pain is the testicle.

Must exclude first

• Testicular torsion

Torsion mimics

• Epididymitis
• Torsion of the appendix testis

Other causes

• Incarcerated inguinal hernia
• Trauma
• Hydrocele
• Varicocele
• Idiopathic scrotal edema
• IgA vasculitis
• Referred pain from nephrolithiasis or appendicitis

Next step

• The case is now an acute scrotum case. The next question is whether the history and examination create a high suspicion for testicular torsion or an uncertain diagnosis requiring urgent Doppler ultrasound.

Look for torsion

• Testicular lie: high-riding or horizontal.
• Cremasteric reflex: absent is concerning; a present reflex does not completely exclude torsion.
• Degree and location of tenderness/swelling.
• Compare both testes.

Also look for mimics

• Focal epididymal tenderness/swelling → epididymitis.
• Blue-dot sign or focal upper-pole nodule → torsion of appendix testis.
• Inguinal hernia.
• Trauma, skin changes, or Fournier gangrene.

This is a high-suspicion torsion.

• Sudden severe unilateral pain.
• Nausea.
• High-riding, horizontal testis.
• Absent cremasteric reflex.

Action

• Call urology immediately.
• High clinical suspicion → urgent surgical exploration.
• Do not delay definitive care just to obtain an ultrasound.

Do not simply wait.

• Arrange the fastest route to operative urologic care: backup urologist, transfer, or another facility with OR capability.
• If Doppler ultrasound is immediately available without delaying transfer or surgery, obtain it while the definitive plan is being arranged.

Manual detorsion

• If there will be a meaningful delay to surgery, attempt manual detorsion while awaiting definitive care.
• Usually rotate the affected testis outward (“open the book”); stop or reverse direction if pain worsens or there is resistance.
• Pain relief or return of flow suggests successful detorsion.
• Successful manual detorsion does not eliminate the need for surgical exploration and orchiopexy.

Doppler ultrasound

• Decreased or absent intratesticular blood flow compared with the other side.
• Twisted spermatic cord / whirlpool sign.
• Enlarged, edematous testis; echotexture may become heterogeneous as ischemia progresses.
• Reactive hydrocele or scrotal-wall thickening may be present.

Testicular torsion.

• The ultrasound confirms what the history and exam already strongly suggested.
• Immediate operative detorsion and fixation are required.
• Continue the urgent transfer/OR pathway; do not allow the ultrasound result to create a new delay.

Think intermittent testicular torsion — torsion-detorsion.

• Ask about prior episodes of sudden severe unilateral pain that resolved spontaneously.
• After spontaneous detorsion, the exam may improve and Doppler flow may be normal or even increased.
• Look for an abnormal horizontal lie or spermatic-cord twist/whirlpool sign.
• A reassuring Doppler does not make a convincing torsion story safe for discharge.

Action

• Urgent urology evaluation.
• Recurrent intermittent torsion generally requires orchiopexy to prevent a future sustained torsion.

Think epididymitis.

• More gradual onset, urinary/urethral symptoms, and focal epididymal tenderness favor epididymitis.
• Doppler often shows epididymal hyperemia with preserved/increased testicular flow.
• Obtain urinalysis/culture and STI testing when appropriate.
• At age 18, treatment is based on the likely infectious etiology, not age alone.

Think orchitis / epididymo-orchitis.

• Isolated orchitis is less common than epididymo-orchitis.
• Viral symptoms, including mumps when epidemiologically plausible, support orchitis.
• Ultrasound usually shows increased testicular blood flow, not absent flow.
• Viral orchitis is generally supportive care; bacterial epididymo-orchitis is treated according to the suspected infection.

Think testicular cancer.

• Testicular cancer usually presents as a painless mass, but pain can occur.
• Solid intratesticular mass → urgent urology evaluation.
• Obtain AFP, β-hCG, and LDH when cancer is suspected.
• Normal tumor markers do not exclude testicular cancer.

As little as possible.

• The best outcomes occur with detorsion in roughly the first 4–6 hours, and the chance of salvage falls as ischemia time and the degree of twisting increase. Do not treat six hours as a hard cutoff: viable testes are still found after 12 and even 24 hours, so a late presentation still needs urgent surgical evaluation.

Immediate OR for scrotal exploration.

• Detorse the affected testicle and assess viability.
• Viable testicle → orchiopexy.
• The contralateral testicle is commonly fixed at the same operation because the predisposing anatomy may be bilateral.
• Clearly nonviable testicle → orchiectomy.

Do not let improvement after manual detorsion cancel surgery.

• Residual or recurrent torsion can remain despite pain relief.

“Eighteen-year-old male with about three and a half hours of acute left testicular pain that he initially reported as flank pain. He has a high-riding horizontal left testicle with an absent cremasteric reflex, and Doppler shows absent intratesticular flow with a spermatic-cord whirlpool sign. He is NPO with IV access and analgesia. This is testicular torsion and he needs immediate operative detorsion and fixation.”

Testicular torsion until proven otherwise.

No. Urgent urology/surgical exploration; imaging should not delay definitive care.

Strongly supports torsion.

No. A present cremasteric reflex does not exclude testicular torsion.

Decreased/absent intratesticular flow; look for spermatic-cord whirlpool sign.

No — think early, partial, or intermittent torsion.

Intermittent testicular torsion.

No. He still needs surgical exploration and orchiopexy.

As soon as possible; ideally within about 4–6 hours.

Wrong. Still obtain urgent urologic evaluation/exploration.

Think testicular cancer; ultrasound + AFP, β-hCG, LDH + urology.