What is the likely cause and appropriate treatment for a 23-month-old child presenting with a lump in the groin area?

Groin Lump in a 23-Month-Old Child

The most likely diagnosis is an inguinal hernia, and the child should be referred to a pediatric surgeon for elective surgical repair within weeks to months, as all inguinal hernias in infants require repair to prevent incarceration and gonadal complications. 1

Most Likely Diagnosis: Inguinal Hernia

Inguinal hernia is by far the most common cause of a groin lump in this age group, occurring in up to 5% of children, with over 90% being indirect hernias related to a patent processus vaginalis. 1 The diagnosis is typically made clinically when parents report an intermittent bulge in the groin that may extend into the scrotum (in boys) or labia (in girls), often appearing with crying, straining, or standing. 1

Key Clinical Features to Assess:

• Reducibility: Can the lump be gently pushed back into the abdomen, or is it fixed and tender (suggesting incarceration)? 1
• Laterality: Right-sided hernias occur in 60% of cases, left-sided in 30%, and bilateral in 10%. 1
• Associated symptoms: Irritability, vomiting, or inability to reduce the mass indicates incarceration requiring urgent surgical intervention. 1

Critical Differential Diagnoses

Hydrocele

A hydrocele presents as a smooth, non-tender scrotal swelling that transilluminates with light, typically resolves spontaneously by 18-24 months, and does not extend above the pubic tubercle. 1 Unlike hernias, hydroceles do not change size with crying or straining.

Femoral Hernia (Rare but Important)

Femoral hernias are exceedingly rare in children (0.5% of all pediatric hernias) but are frequently misdiagnosed as inguinal hernias. 2, 3 They present as a lump below and lateral to the pubic tubercle, whereas inguinal hernias appear above and medial to this landmark. 2, 3 Femoral hernias have a higher incarceration risk and should be suspected if a groin mass recurs shortly after inguinal hernia repair. 2, 3

Lymphadenopathy

Enlarged inguinal lymph nodes are typically multiple, mobile, and associated with lower extremity infections, diaper rash, or systemic illness. 4

Imaging Recommendations

Ultrasound is the first-line imaging modality when the diagnosis is uncertain on physical examination, with high sensitivity for distinguishing hernias from hydroceles, lymph nodes, and other groin masses. 4 The American College of Radiology supports ultrasound with Doppler for evaluating pediatric groin lesions due to lack of radiation and excellent soft tissue resolution. 5

Imaging is NOT required if the clinical diagnosis of reducible inguinal hernia is clear on examination. 1

Management Algorithm

For Reducible Inguinal Hernia:

Refer to a pediatric surgeon for elective repair within weeks to months. 1 All inguinal hernias in infants require surgical repair because:

• Risk of incarceration ranges from 6-18% in the first year of life 1
• Incarceration can lead to bowel ischemia and gonadal infarction 1
• The hernia will not resolve spontaneously 1

For Incarcerated Hernia (Non-Reducible, Tender Mass):

This is a surgical emergency. 1 The child should be:

• Transferred immediately to the nearest emergency department 1
• Kept NPO (nothing by mouth) 1
• Given IV access and analgesia 1
• Evaluated urgently by a pediatric surgeon for manual reduction or emergency surgery 1

Timing of Surgery:

The American Academy of Pediatrics recommends repair before hospital discharge in premature infants or within 2-4 weeks of diagnosis in term infants to balance the risk of incarceration against anesthetic complications. 1 Delaying repair beyond several weeks significantly increases incarceration risk. 1

Critical Pitfalls to Avoid

• Missing a femoral hernia: If no inguinal hernia sac is found at surgery, always explore the femoral canal medially to the femoral vessels. 2, 3
• Assuming a hydrocele in a child >18 months: Persistent hydroceles after 18-24 months often communicate with the peritoneal cavity and require surgical repair like hernias. 1
• Delaying repair: Even asymptomatic reducible hernias should be repaired within weeks, as incarceration can occur unpredictably. 1
• Inadequate examination: Always examine the child while standing and crying to make the hernia more apparent. 1

Infants with medical conditions that increase operative risk (congenital heart disease, prematurity) should be referred specifically to a pediatric surgeon rather than a general surgeon. 1