Anaplastic Sarcoma of the Kidney: A Rare Unique Renal Neoplasm.

Anaplastic sarcoma of the kidney (ASK) is an extremely rare tumor, which usually presents as a large renal mass. Microscopically, the tumor is composed of pleomorphic mesenchymal spindle cells with marked atypia, associated with chondroid differentiation and focal round primitive mesenchymal cells. Herein, we present a case of anaplastic sarcoma of the kidney in a 3-year-old female, who presented with a large abdominal mass. To the best of our knowledge, less than 25 cases are reported in the literature. In addition, this is the first case reported from the Middle East.