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How not to miss .... a torsion of the testis

Mr Chris Dawson advises on the key signs and pitfalls in diagnosing torsion of the testis in primary care

Mr Chris Dawson advises on the key signs and pitfalls in diagnosing torsion of the testis in primary care

Worst outcomes if missed

If missed, testicular torsion leads to infarction and necrosis of the affected testis, necessitating orchidectomy. This may have several long-term sequelae including impaired future fertility and psychological problems related to body image issues.

Missed torsion may also lead to infection and abscess if not quickly dealt with.


• The annual incidence is about one in 4,000 males under 25.

• The condition can occur at any age, but is most common in adolescents, and sometimes in neonates. Peak incidence occurs between the ages of 10 and 25.

• Between 16% and 42% of boys presenting with acute scrotal pain have testicular torsion.

• Some 90% of cases are caused by ‘intravaginal torsion' where the tunica vaginalis covers not only the testis and epididymis but also the spermatic cord – this leads to the so-called ‘bell clapper deformity'.

• In most cases of torsion there is no other precipitating event.

• Trauma accounts for between 4% and 8% of cases.

• Ischaemia can occur as soon as four hours after torsion.

• Studies have shown testis salvage rates of 90% if surgical detorsion occurs within six hours of symptom onset, falling to 50% after 12 hours and less than 10% after 24 hours.

Symptoms and signs

Torsion of the testis occurs when the body of the testis twists around the spermatic cord, cutting off blood supply to the testis. Pain may not always be a significant feature in boys presenting before puberty and until inflammatory changes occur the pain may be almost absent. Children localise the pain very poorly and so the testes should always be examined in any boy presenting with acute abdominal pain.

The affected testis is usually tender and often lies higher in the scrotum – it may also lie abnormally because of shortening of the spermatic cord due to torsion. Absence of the cremasteric reflex on the affected side is 100% sensitive and 66% specific for the diagnosis of torsion.

Differential diagnosis

The differential diagnosis is that of an acutely painful scrotum – other causes include:

• Torsion of the appendix testis (torsion of Hydatid of Morgagni). This condition is more common in children than testis torsion and is sometimes visible as a tender nodule with blue discolouration on the upper pole of the testis (‘blue spot' sign). Patients with torsion of the appendix testis usually present later than those with torsion of the testis but this fact is not diagnostic.

• Epididymitis/orchitis – this is much less common in males before puberty. Patients with epididymitis are more likely to present with a tender epididymis, although in practice this can be difficult to determine in a child who is unwilling to be examined because of the pain. Fever often occurs in epididymitis. Normal urinalysis does not exclude epididymitis any more than an abnormal urine result excludes testicular torsion.

• Incarcerated hernia.

• Varicocele.

• Trauma – scrotal pain lasting more than an hour after an episode of scrotal trauma should be referred urgently for evaluation to exclude possible trauma-induced torsion.

• Idiopathic scrotal oedema is characterised by sudden scrotal swelling (may be bilateral) and redness. Crucially, there is no pain with this condition and the scrotum is not tender.

First-line investigations

Opinion is divided over the usefulness of imaging in the evaluation of the patient with an acutely painful scrotum. Certainly there is no place for imaging in primary care and the patient should be referred as an emergency for a specialist opinion.

Some studies have suggested a place for Doppler ultrasound for the evaluation of the acute scrotum. This test should be restricted to use in hospital for those cases where the diagnosis is more equivocal and for those cases where the duration of pain exceeds six to 12 hours.

Doppler ultrasound may reduce the number of patients requiring exploration of the scrotum but the scan may be difficult to perform in children, may give a falsely reassuring suggestion of normal arterial flow, and is also operator dependent.

Second-line investigations

Scintigraphy and dynamic contrast enhanced MRI of the scrotum have shown similar sensitivity and specificity to ultrasound but are subject to the same caveats as mentioned above.

Mr Chris Dawson is a consultant urologist at the Edith Cavell Hospital, Peterborough

Competing interests: none declared

Use of ultrasound in suspected testes torsion is recommended by some Ultrasound of normal testes

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