Magnetic resonance imaging findings of renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion in adults: a pilot study

PurposeThe purpose of the study was to retrospectively analyze MRI findings of renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion (Xp11.2/TFE RCC) in adults.MethodsSixteen patients with Xp11.2/TFE RCC were reviewed retrospectively. The clinical characteristics and imaging features were assessed and then compared between metastatic and non-metastatic subgroups.ResultsThe mean age at diagnosis was 47.4 (20-76) years. Seven (44 %) patients were men, and nine (56 %) patients were women. The lesions predominantly exhibited an endophytic distribution (n=14, 88 %) with a capsule (n=16, 100 %), accompanied by solid and cystic patterns (n=12, 75%) and hemorrhage (n=11, 69 %). The tumors prevalently appeared hyper- to isointense on T1WI (n=14, 88 %), hypointense on T2WI (n=13, 81 %), and hyperintense on DWI (n=16, 100 %) with a lower ADC (P<0.001) than that of the surrounding tissue. The tumors were less enhanced than the normal renal cortex in all phases with a prolonged enhancement pattern (P0.001). In addition, six patients (38 %) developed recurrence or metastases. The RCCs with metastases showed an irregular shape (P=0.013), an incomplete capsule (P=0.018), heterogeneous solid-cystic patterns (P=0.034), and hemorrhage (P=0.037) than non-metastatic subgroups.ConclusionsMRI provides valuable information for the diagnosis of adult Xp11.2/TFE RCCs. Features including irregular shape, incomplete capsule, mixed solid-cystic pattern, and hemorrhage may indicate the occurrence of recurrence or metastases.