Multi-Phase Multiple Detector Computed Tomography (MDCT) Enhancement Patterns and Morphological Features of Chromophobe Renal Cell Carcinoma: An Analysis of 67 Cases.

BACKGROUND Chromophobe renal cell carcinoma (ChRCC) is difficult to diagnose preoperatively. We investigated multiple detector computed tomography (MDCT) plain scan and multi-phase CT enhancement features to aid ChRCC preoperative diagnosis. MATERIAL AND METHODS MDCT data of patients with pathologically confirmed ChRCC were retrospectively analyzed. We calculated the ratios of the CT value for the solid part of the mass to those of the renal cortex, aorta, and inferior vena cava. These ratios were designated as L01-3 for the CT plain scan images, La1-3 for the cortical phase, Lv1-3 for the nephrographic phase, and Lp1-3 for the pelvic phase. We classified the masses into types I, II, III, and IV by type of enhancement. RESULTS Sixty-eight masses were included and divided into 3 groups by tumor size (groups A, B, and C). Percentages of calcification, central scars, and small vessel signs were significantly different during the cortical phase for masses in all groups (all P<0.01). Significant differences in enhancement were observed between tumors with severe and mild degrees of enhancement (P<0.01); and among La1, Lv1, and Lp1; La2, Lv2, and Lp2; and La3, Lv3, and Lp3 after enhancement during the cortical, nephrographic, and renal pelvic phases (all P<0.01). The most common type of mass enhancement was type II, followed by type I, and differences between these 2 types were significant (P<0.001). CONCLUSIONS Although the MDCT features for ChRCC are diverse, MDCT helped preoperatively diagnose ChRCC. Multiple MDCT features are needed to improve the accuracy of preoperative diagnosis.