Multi-slice spiral CT findings of renal cell carcinoma associated with XP11.2 translocation-TFE gene fusion / 中华放射学杂志

ABSTRACT

Objective To investigate the MSCT features of the renal cell carcinoma associated with XP11.2 translocation-TFE gene fusion ( XP11.2-TFE Ca).Methods The MSCT features of XP11.2-TFE Ca in six patients were retrospectively analyzed,which were confirmed by postoperative histopathology.All the tumor features were recorded and compared to the histopathological findings.Variance test analysis was performed to compare the CT values among tumor,normal renal cortex and normal renal medulla.Results XP11.2-TFE Ca appeared as a solitary lesion in all the 6 patients,which limited in the medulla in 3 patients and infiltrated both medulla and renal pelvis in other 3 patients.The tumor diameter ranged from 3.8 to 5.2 cm [mean diameter,(4.2 ± 1.3) cm],And the adjacent renal cortex was compressed or involved.Four lesions were oval,2 lesions were irregular shape.Tumor capsule showed in all lesions in the six patients.Cystic component and retroperitoneal lymph node metastasis respectively occurred in one patient.In all lesions,calcification was not detected.On unenhanced CT scan phase,the CT values of the normal cortex,normal medulla and XP11.2-TFE Ca were (42 ±5),(38 ±4) and (48 ±4) HU respectively,with no significant statistical difference ( F =1.267,P ＞ 0.05 ) ; on cortical nephrographic phase after contrast injection,they were ( 174 ± 10 ),( 72 ± 8 ) and ( 100 ± 9) HU respectively,with significant statistical difference among the three groups (F =6.588,P ＜ 0.01) ; on parenchymal nephrographic phase,they were (207 + 12),(109 +8) and ( 121± 11) HU respectively,with significant statistical difference (F =7.172,P＜0.01) ; and on the excretory phase,they were (148 ± 12),(67 ±8) and (83 ±7) HU respectively,with significant statistical difference ( F =2.678,P ＜ 0.05 ).On each phase of contrast-enhanced MSCT scan,the enhancement of XP11.2-TFE Ca was higher than that of the medulla and lower than that of the cortex.Conclusions XP11.2-TFE Ca had some characteristic MSCT features.Comprehensive analysis of its MSCT features may help for improving the diagnosis.