嫌色细胞肾癌和乳头状肾细胞癌的多排螺旋CT特征及其鉴别诊断

MSCT Features and Differential Diagnosis of Chromophobe Cell Renal Carcinoma and Papillary Renal Cell Carcinoma

目的探讨嫌色细胞癌(ChRCC)和乳头状肾癌(pRCC)多排螺旋CT的特征及其鉴别诊断。方法收集7例ChRCC和14例pRCC(其中1例合并透明细胞肾癌,未纳入统计)经手术病理证实的患者临床资料,分析MSCT形态学和多期增强扫描的特征,采用受试者工作特征曲线(ROC)分析鉴别ChRCC、pRCC的价值。结果 7例ChRCC肿瘤体积均较大,平均直径8. 2 cm,均伴有囊变坏死、出血,囊变以多发边界清晰小囊变为主,4例伴有钙化。13例pRCC平均直径5. 8 cm,仅有2例(直径<3. 0 cm)密度均匀,其余11例伴有囊变坏死、出血,5例伴有钙化。增强后ChRCC动脉期强化明显,静脉期和排泄期下降,pRCC表现为轻中度持续强化,排泄期略有下降。ChRCC和pRCC动脉期的强化百分比分别为(154. 6±75. 45)%、(71. 5±57. 6)%,差异有统计学意义(P=0. 013);但静脉期及排泄期2种肿瘤的强化百分比差异无统计学意义。ChRCC和pRCC动脉期的相对强化比值分别为(0. 57±0. 16)、(0. 40±0. 12),差异有统计学意义(P=0. 016);静脉期及排泄期2种肿瘤的相对强化比值差异无统计学意义。病灶动脉期强化百分比和相对强化比值鉴别2种肿瘤ROC曲线下面积分别为0. 813、0. 802。以动脉期强化百分比阈值为108. 0%时,鉴别2种肿瘤的敏感度为85. 7%,特异度为76. 9%,Youden指数为0. 626;以动脉期相对强化比值阈值为0. 48时,鉴别2种肿瘤的敏感度、特异度分别为71. 4%、76. 9%,Youden指数仅为0. 483。结论 ChRCC多以边界清楚小囊变为主,增强后部分肿瘤表现"快进快出"强化方式。pRCC增强表现轻中度持续强化,排泄期略有下降。动脉期病灶强化百分比和相对强化比值有助于鉴别ChRCC和pRCC。

Objective To investigate the characteristics imaging appearances and differential diagnosis of chromophobe cell carcinoma( ChRCC) and papillary renal cell carcinoma( pRCC) using multi-detector CT( MDCT). Methods The clinical data of 7 cases of ChRCC and 14 cases of pRCC( including 1 case with clear cell renal cell carcinoma) confirmed by operation and pathology were collected. The gross morphologic profile and the degree of tumor enhancement on MSCT were analyzed and receiver operating characteristic( ROC) curve were established. Results 7 cases of ChRCC tumors were larger,with an average diameter of 8. 2 cm,which all showed a heterogeneous comsistency( secondary to necrosis,multiple well-defined cystic changes,hemorrhage and 4 cases with calcification). The mean diameter of pRCC was 5. 8 cm in 13 cases,of which 11 cases were also heterogeneous( including cystic degeneration,necrosis,hemorrhage and 5 cases with calcification) while only 2 cases( diameter <3. 0 cm) had homogeneous density. The enhancement of ChRCC peaked on the corticomedullary phase compared with that of pRCC were intermediate vascularity. The enhancement percentages( EP) of ChRCC and pRCC on the corticomedullary phase were154. 6 ± 75. 45% and 71. 5 ± 57. 6%,respectively( P = 0. 013) and the enhancement index( EI) of ChRCC and pRCC on the corticomedullary phase were 0. 57 ± 0. 16 and 0. 40 ± 0. 12,respectively( P = 0. 016). The data showed no significant difference on the nephrographic phase and excretory phase. The area under curve were 0. 813 and 0. 802 respectively for EP and EI,as the threshold value of EP on the corticomedullary phase was 108. 0%,the sensitivity,specificity and Youden index were 85. 7%,76. 9%,0. 626,while the threshold value of EI on the corticomedullary phase was 0. 48,the sensitivity,specificity and Youden index were 71. 4%,76. 9% and 0. 483. Conclusion ChRCC typically exhibits internal well-defined cystic change and some of the tumors show ' wash in and wash out' enhancement and pRCC showed mild to moderate continuous enhancement. The EP and EI on the corticomedullary phase are helpful in differentiating ChRCC and pRCC.