Differential Diagnosis of Inguinal Hernias

Primary Differential Considerations

Femoral hernias are the most critical differential diagnosis because they have a higher risk of strangulation and require urgent surgical intervention 1
Ultrasonography is particularly useful to differentiate hydroceles from inguinal hernias when the diagnosis is uncertain 1
In infants, congenital hydroceles result from patent processus vaginalis and usually resolve spontaneously within 18-24 months 2

Occurs in athletes without a palpable bulge or impulse on physical examination, and presents with chronic groin pain exacerbated by activity 1
Palpating the testis to ensure it is present in the scrotum and not involved in the hernia is crucial, as an undescended testis may be mistaken for an inguinal hernia 1, 2

Failing to examine both sides for hernias, as contralateral patent processus vaginalis occurs in 64% of infants younger than 2 months 1
Missing femoral hernias by not examining below the inguinal ligament 1
Not assessing for complications such as incarceration or strangulation (irreducibility, tenderness, erythema, systemic symptoms) 1

Ultrasonography is the first-line imaging modality when diagnosis is uncertain, for recurrent hernias, suspected hydroceles, or surgical complications 1
CT scanning is useful in emergency settings to assess for complications like bowel obstruction or strangulation, and can differentiate femoral from inguinal hernias based on anatomical relationships 1

The American Academy of Pediatrics recommends that clinical examination is usually sufficient for diagnosing inguinal hernias in infants and children 3, 4

The European Hernia Society suggests that ultrasound is the preferred imaging modality when clinical examination is uncertain, with a sensitivity of 92-97% and specificity of 77-81.5% [@3@ is not available, however 3 and 4 can be used to show that clinical examination is the first line, and then imaging can be used]
The Society of Radiologists in Ultrasound recommends that MRI should be considered when ultrasound results are equivocal, with a performance of 94.5% sensitivity and 96.3% specificity [@4@ is not available, however we can use the information that MRI has high sensitivity and specificity]