Extraskeletal mesenchymal chondrosarcoma of the kidney.

A 61-year-old woman was referred for evaluation of an incidental mass found on the right kidney. Abdominal ultrasonography and computed tomography showed a 3-cm tumor with calcification and peripheral enhancement. Under the diagnosis of renal cell carcinoma, a transabdominal right radical nephrectomy was performed. The pathological diagnosis was extraskeletal mesenchymal chondrosarcoma of the kidney. No recurrence or metastasis occurred during a 6-year follow up. Primary renal chondrosarcoma is extremely rare, this being only the fifth case reported in the English literature, and the patient's extended survival is attributed to the small size of the tumor, as well as early diagnosis and treatment.