Correlation between contrast-enhanced ultrasound features and size of clear cell renal cell carcinoma / 中华医学超声杂志（电子版）

ABSTRACT

Objetcive To analyze the contrast-enhanced ultrasound (CEUS)features in clear cell renal cell carcinoma (CCRCC) of different size and to discuss the diagnostic value of CEUS in CCRCCs. Methods The contrast-enhanced and conventional US features of 80 CCRCCs confirmed pathologically were retrospectively analyzed. Samples were divided into three groups by diameters small CCRCCs (≤30 mm), medium CCRCCs(＞30 mm) and large CCRCCs(＞50 mm). The tumoral vascularity, lesion homogeneity and presence of an anechoic rim were observed on conventional US. The enhancement of echogenicity, homogeneity and pseudocapsule were evaluated on CEUS. Results Among the 80 renal masses, 32 were small CCRCCs, 28 were medium CCRCCs while the large CCRCCs were 20. On conventional US, 18.8%(6/32) of small CCRCCs, 71.4%(20/28) of medium CCRCCs and 95%(19/20) of large CCRCCs demonstrated as heterogeneous and the differences were highly statistically significant, whereas there were no differences in the tumoral vascularity and the presence of pseudocapsule sign among the three groups. On CEUS, 28.1%(9/32) of small CCRCCs, 85.7%(24/28) of medium CCRCCs and 100%(20/20) of large CCRCCs showed a homogeneous enhancement. The incidence of pseudocapsule sign in medium tumors was higher than small and large groups(71.4%,50% and 25%,respectively). There were statistically significant differences among the three groups in the enhanced homogeneity and the presence of pseudocapsule sign. However, all the three groups revealed mainly isoechoic and hyperechoic and there were no differences among them. Compared with conventional US, CEUS depicted significantly the increased tumoral vascularity (51.3% vs. 87.5%) and pseudocapsule sign(22.5% vs. 51.3%). Eight lesions demonstrated heterogeneous contrast enhancement on CEUS while homogeneous on conventional US, but there were no differences in lesion homogeneity between conventional US and CEUS findings. Conclusions Different sizes of CCRCC showed distinct CEUS features in the enhanced homogeneity and the presence of pseudocapsule sign. CEUS is more effective on improving the sonographic characteristics of tumoral visualization and may provide important information of US findings for the diagnosis of renal cell carcinoma.