Sarcomatoid Renal Cell Carcinoma and Collecting Duct Carcinoma

Rationale and Objectives To investigate whether imaging features on multiphasic multidetector computed tomography (MDCT) can help discriminate sarcomatoid renal cell carcinoma (RCC) and collecting duct carcinoma (CDC) from other solid renal masses. Materials and Methods With institutional review board approval for this HIPAA-compliant study, we derived a cohort of 7 sarcomatoid RCCs, 4 CDCs, 165 clear cell RCCs, 56 papillary RCCs, 22 chromophobe RCCs, 49 oncocytomas, and 16 lipid-poor angiomyolipomas with preoperative multiphasic MDCT with up to four phases (unenhanced, corticomedullary, nephrographic, and excretory). Each lesion was reviewed for contour, spread pattern, pattern of enhancement, neovascularity, and calcification. Results Sarcomatoid RCCs and CDCs were more likely than other solid renal masses to have an irregular contour (64% vs 2%, P P Conclusions Solid renal lesions with an irregular contour or an infiltrative spread pattern are suspicious for sarcomatoid RCC or CDC.