肾血管平滑肌脂肪瘤与肾癌的CT鉴别诊断

CT differential diagnosis between angiomyolipoma and carcinoma of kidney

目的 探讨血管平滑肌脂肪瘤 (AML)杯口征与劈裂征的形成机制 ,评价其对AML与肾癌的鉴别诊断意义。方法 收集CT或病理诊断直径 5cm以下的AML 30例 ,经手术病理证实直径小于 4cm的原发性肾癌 2 6例 ,分别统计AML组与肾癌组“杯口征”及“劈裂征”的阳性率 ,进行盲法研究并与病理表现相对照。结果 30例AML中 2 5例杯口征阳性 (83 3% ) ,2 2例劈裂征阳性 (73 3% ) ,其中 7例无或少脂成分AML中 ,杯口征阳性 6例 ,劈裂征阳性 5例 ;2 6例小肾癌中 6例杯口征阳性(2 3 1% ) (P <0 0 0 5 ) ,5例劈裂征阳性 (19 2 % ) (P <0 0 0 5 )。经统计学检验 ,笔者结果及盲法结果与病理结果的差异无显著性意义 (χ2 =2 333,P >0 1;χ2 =0 177,P >0 5 )。结论 杯口征与劈裂征可在一定程度上反映AML的生物学特性 。

Objective To investigate the formation of the cup sign and split sign in renal neoplasms and to evaluate the significance of these signs in CT differential diagnosis between angiomyolipoma (AML) and carcinoma of the kidney. Methods Thirty cases of AMLs of kidney less than 5 cm in diameter confirmed pathologically or by the fat component shown in CT, and 26 cases of primary renal carcinomas less than 4 cm in diameter confirmed by operation and pathology were included in this study. The positive rates of cup sign and split sign of AML group and renal carcinoma group were calculated respectively and studied with blind method and pathologic comparison. Results Of the 30 AMLs, cup sign was positive in 25 cases (83.3%) and split sign in 22 (73.3%). Of the 26 small renal carcinomas, cup sign was positive in 6 cases (23.1%) and split sign in 5 (19.2%). 7 AMLs without fat component or with too little fat to be seen with CT showed positive findings of cup sign in 6 (85.7%) and split sign in 5 (71.4%), respectively. The statistical results showed that the differences between the results of the writer and blind method, as well as between the imaging observation and pathologic findings were not significant (χ~2=2.333, P>0.1; χ~2=0.177, P>0.5). Conclusion To some extent, the cup sign and split sign on CT reflect the biologic character of AMLs, and the signs are helpful in making the specific diagnosis of AML combined with other imaging manifestations.