Osteosarcoma metastatic to the kidney.

Two clinically silent renal metastatic lesions from primary osteogenic sarcoma were first detected on radionuclide bone scan. A needle biopsy performed under the guidance of abdominal ultrasonography confirmed the diagnosis. Prior to nephrectomy, further definition of the metastatic lesion was attained using enhanced computed tomography. A review of the English literature revealed only six previous cases of metastatic osteosarcoma detected in the kidney prior to autopsy.