Clear cell sarcoma of the kidney: a case report.

Clear cell sarcoma of the kidney is a rare malignant neoplasm of childhood, known for its aggressiveness, its tendency for recurrence, and to metastasize to bone. We report the observation of 8-month-old child presenting with a large abdominal mass. Clinically, it was diagnosed as Wilm's tumor, and left nephrectomy was done. Grossly, 10 cm×8 cm×3.5 cm globular, white, encapsulated, smooth mass uniformly involving the whole kidney was noted. Histologically, the tumor was diagnosed as clear cell sarcoma with renal vein showing presence of tumor embolus in lumen. The tumor was given stage-II (NWTS-5 protocol). Immunohistochemistry showed vimentin positive and cytokeratin negative tumor cells. The child is currently undergoing chemotherapy and has not yet shown any sign of bony metastasis.