Diagnostic imaging of renal sarcomas and sarcomatoid renal cell carcinomas

Renal sarcomas and sarcomatoid renal cell carcinomas are extremely rare neoplasms of the kidney. The Authors reviewed the pathological files and report the features of 12 renal sarcomas and 22 sarcomatoid carcinomas. Leiomyosarcomas and liposarcomas were the most common tumors among the sarcomas, while sarcomatoid carcinomas presented different proportions of carcinomatous and sarcomatous elements. The findings of diagnostic imaging modalities, including plain film and intravenous urography (with nephrotomography), arteriography, ultrasonography and computed tomography, are reported. The findings enable the diagnosis of the nature of these masses. However, the actual experience does not allow a prospective diagnosis of renal sarcoma or of sarcomatoid carcinoma. The mesenchymal nature of the tumor may be suspected when the capsular or sinusal origin is evident, a fatty component is seen within a large aggressive mass and when a hypovascular mass with capsular vessels is seen in angiography.