Affects children <15yr, 2/3 of cases diagnosed before age 5
Arises from persistent embryonal renal cells
Most common renal malignancy in children
10-15% will have mets at presentation (lungs)  
10% of cases are associated with malformation syndromes such as WAGR, Denys-trash, Beckwith-Wiedemann
Wilms' tumor
Neuroblastoma
Neuroblastoma 
Other renal cell tumors are rare in children
Pheochromocytoma
Vestibular schwannoma
Coma
Giant cell tumor