Malignant rhabdoid tumor of the kidney: imaging features in two cases.

Two new cases of malignant rhabdoid tumor of the kidney (RTK) in childhood are reported. Both presented with large abdominal masses and developed hypertension and one became hypercalcemic during the course of the disease. In each case disseminated disease and death occurred within three months of diagnosis. The findings on imaging consisted of large renal masses with a central site of origin, distant metastases at the time of presentation, and a subcapsular fluid collection in one of the two patients. The clinical and imaging features of RTK may suggest this diagnosis when faced with a primary renal neoplasm in childhood.