The most common presentation of a child with Wilm\'s tumor is –
Presentation of Wilm's tumor :

Asymptomatic abdominal mass (most common).       
Abdominal pain (30%).                               
Hypertension (25%).
Heamaturia (10-25%).
Fever (20%).
Anorexia and vomiting.
As asymptomatic abdominal mass
Haematuria
Hypertension
Hemoptysis due to pulmonary secondary