CT形态学特征鉴别乏脂质血管平滑肌脂肪瘤和肾细胞癌

CT Morphological Features Distinguish the Fat-poor Angiomyolipoma and Renal Cell Carcinoma

目的探讨CT形态学特征鉴别乏脂质血管平滑肌脂肪瘤(fat-poor angiomyolipoma,FpAML)和肾细胞癌(renal cell carcinoma,RCC)的价值。方法共收集34例经病理确诊为RCC (21例)或FpAML (13例)。所有病变均未有肉眼所见脂肪成分。形态学分析包括啤酒溢出征和接触面成角征,啤酒溢出征指肿块膨出部分与邻近肾包膜接触长度不小于3mm,接触面角度征指肿块实质部分的角度不大于90。计算分析上述两个特征鉴别RCC和FpAML的敏感度(sensitivity)、特异度(specificity)、阳性预测值(positive predictive value,PPV)、阴性预测值(negative predictive value,NPV)及准确性(accuracy)。结果啤酒溢出征鉴别FpAML和RCC的敏感度,特异度,PPV,NPV和准确率分别为76.9%,90.5%,83.3%,8 6.4%,8 5.3%;接触面成角征的敏感度,特异度,PPV,NPV和准确率分别为53.8%,81.0%,63.6%,73.9%,70.6%。结论增强CT的形态学分析可用于鉴别FpAML和RCC。啤酒溢出征是诊断FpAML的潜在影像标志物。

Objective To investigate the value of morphologic analysis using computed tomography(CT) in differentiating fat-poor angiomyolipoma(FpAML) from renal cell carcinoma(RCC). Methods A total of 34 patients with pathologically confirmed RCC(n=21) or FpAML(n=13) were evaluated. All renal lesions were less than 4 cm in size and had no gross fat on CT images. For morphologic analysis, overflowing beer sign and angular interface were evaluated. Overflowing beer sign was defined as contact between bulging-out portion of a mass and the adjacent renal capsule of 3 mm or greater. Angular interface was defined as the angle of parenchymal portion of a mass of 90°or less. Sensitivity, specificity, positive predictive value(PPV), negative predictive value(NPV), and accuracy were calculated. Results Sensitivity, specificity, PPV, NPV, and accuracy were 76.9%,90.5%,83.3%,86.4%,85.3% with overflowing beer sign for FpAML. While they were 53.8%,81.0%,63.6%,73.9%,70.6% with angular interface for FpAML, respectively. Conclusion Morphologic analysis with contrast-enhanced CT may be useful for distinguishing FpAML from RCC. Overflowing beer sign has the potential as an imaging biomarker for FpAML.