Childhood 2-5y, 98% in <10y.
WT1 gene on 11p
embryonic blast cell tumour
Abdominal Mass, rarely fever, pain & haematuria.
Sporadic, unilateral (80%) & Familial (10%) Bilateral, associated with other congenital malformations.
Gross: Large, bulky, soft, grey haemorrhagic tumour
Microscopy: Dark, blue, embryonic blast cells forming primitive tubules & glomeruli.
