What is the typical presentation of Wilms tumor (Nephroblastoma)?

Wilms tumor, also known as nephroblastoma, often presents as an asymptomatic abdominal mass in children. Unlike some other abdominal tumors, a Wilms tumor typically does not cross the midline due to the presence of surrounding structures. This characteristic is notable because it helps in differentiating Wilms tumor from other abdominal masses or conditions, such as hepatoblastoma or lymphoma, which may present differently.

Children with Wilms tumor may not exhibit symptoms initially, and the mass is often discovered incidentally during a routine examination or imaging for another issue. Asymptomatic presentations at the time of diagnosis make it essential for healthcare providers to maintain a high level of suspicion for Wilms tumor in pediatric patients, especially when an abdominal mass is palpated.

While other symptoms like pain, fever, weight loss, jaundice, and irritability may occur in various other conditions or advanced cases of different tumors, they are not typical features of Wilms tumor at the time of presentation. Many of these symptoms may indicate more systemic illness or complications rather than being indicative of nephroblastoma itself. Thus, recognizing the classic presentation of an asymptomatic abdominal mass that does not cross the midline is crucial in clinical practice.