A 4-year-old with a swollen abdomen and good appetite is most likely to have which diagnosis?

• A. Wilms tumor (nephroblastoma)
• B. Acute appendicitis
• C. Intussusception
• D. Hepatoblastoma

Answer: (A)

Painless, firm abdominal swelling in a preschool child most strongly points to Wilms tumor, a renal tumor. In children around age 2–4, this is the most common renal neoplasm and typically presents as a unilateral, smooth, non-tender abdominal mass that can cause noticeable swelling while the child maintains a normal or good appetite. Hypertension may be present due to renin production by the tumor, which further supports a renal origin.

Acute appendicitis would present with abrupt abdominal pain, fever, vomiting, and a tender right lower quadrant abdomen rather than a soft, painless mass. Intussusception tends to cause intermittent abdominal pain with episodes of drawing up the legs and sometimes a sausage-shaped mass, usually in younger toddlers. Hepatoblastoma presents as a liver mass in younger children (often under 3) and may be associated with poor appetite and liver-related symptoms, not a primary renal mass.