Wilms' tumour
Wilms' tumour arises from the embryonal tissues in the kidney. It affects children
of all ages but is mostly found in one- to three-year-olds. The tumour usually
develops in one kidney but some children may have both kidneys affected. A few
children with Wilms' tumour may have other abnormalities at birth or in early
childhood, such as hemihypertrophy (when one arm or leg, or one side of the
body, is larger than the other) and aniridia (when the iris, the coloured portion
of the eye, is absent).