<prompt> Which of the following is false about Wilms tumor:September 2010Presents before the age of 5 yearsMostly presents as abdominal massSpreads mostly by lymphaticsResponds well to treatment  <response>: Ans. C: Spreads mostly by lymphaticsWilms tumor or nephroblastoma is cancer of the kidneys that typically occurs in children, rarely in adults. The majority 75 occur in otherwise normal children 1-6 years; a minority 25 is associated with other developmental abnormalities.It is highly responsive to treatment, with about 90 of patients surviving at least five years.Most nephroblastomas are unilateral, being bilateral in less than 5 of cases.They tend to be encapsulated and vascularized tumors that do not cross the midline of the abdomen.In cases of metastasis it is usually hematogenous and to the lung. 