Clear cell sarcoma of the kidney in children: a distinct entity.

Four cases of clear cell sarcoma of the kidney in children are reported. The specificity of the tumor is examined. The pathologic features, the clinical presentation, and the occurrence of bone metastasis are reasons to distinguish clear cell sarcoma from the Wilms' tumor group. The poor prognosis may be improved in the future by radical resection associated with polyvalent chemotherapy.