Spinal cord and bone metastasizing renal tumor of childhood.

In recent reports on renal tumors of childhood with bone involvement neoplasms originally considered to be Wilms tumor have been assigned to new groups. After reviewing the literature, we knew that Wilms tumor rarely metastasizes in this way. Our case illustrates the unique biological feature of the rare, unfavorable histology Wilms tumor variant know as 'clear cell sarcoma of the kidney' (CCSK). Metastases to the spinal cord, as observed in our patient are distinctly unusual. To our knowledge, only two previous cases have been reported in the world literature.