Mesenchymal chondrosarcoma of the kidney.

A case of mesenchymal chondrosarcoma of the kidney, with osseous metastases, is presented in this article, and the clinical, radiologic, and histopathologic features of this uncommon neoplasm are discussed. The addition of this case to those previously reported in the literature brings the total number of reported cases of mesenchymal chondrosarcoma of extraskeletal origin to 42. None of the previously reported cases originated from the kidney. The metastatic pattern of this case illustrates the propensity of mesenchymal chondrosarcoma to metastatize to unusual locations.