All are true about Wilm's tumor, EXCEPT:

80% of children with Wilm's tumor present present under 5 years of age. The mean age of diagnosis is 3 years. 6% of patients with Wilm's tumor have bilateral disease. Bilateral disease is more common in familial type. Clinical features: Most patients presents with an abdominal mass, others can present with hematuria, hypeension, abdominal pain, fever, anorexia and vomiting. Prognostic factors: Prognostic factors are staging, pathology and ploidy. Diploid tumors a better prognosis than hyperdiploid tumors. Ref: Essential paediatrics by O P Ghai, 6th edn, page 574-5