What should be suspected in a child presenting with abdominal pain and an abdominal mass?

In a child presenting with abdominal pain and an abdominal mass, one condition that should be suspected is Wilms tumor. Wilms tumor, or nephroblastoma, is a kidney cancer that primarily affects children and is typically characterized by the presence of a palpable abdominal mass. Along with the abdominal mass, it can present with symptoms such as abdominal pain, hematuria (blood in urine), and occasionally hypertension.

The key symptom of an abdominal mass is particularly indicative in the context of Wilms tumor, as the mass is often large enough to be felt during a physical examination. The tumor usually occurs in one kidney but can also affect both kidneys in some cases. Prompt recognition and diagnosis of Wilms tumor are crucial for effective treatment, which usually involves surgery and possibly chemotherapy.

In contrast, while conditions like intussusception and appendicitis can also cause abdominal pain, they typically do not present with a noticeable abdominal mass in the same way that Wilms tumor does. Intussusception may present with "currant jelly" stools and abdominal distension, and appendicitis usually causes localized tenderness rather than a mass and is accompanied by other signs such as fever or nausea. Constipation can lead to abdominal discomfort and distension but is less likely