Lessons from 801 clinical TFE3/TFEB fluorescence in situ hybridization assays performed on renal cell carcinoma suspicious for MiTF family aberrations.

Clinical TFE3/TFEB FISH assays successfully identified and confirmed rare MiTF-RCC with TFE3 and TFEB rearrangements. Although morphologic and biomarker features associated with a kidney tumor may be suggestive of MiTF-RCC, clinical TFE3/TFEB FISH assays are crucial for a confirmation and definitive subclassification of patients with MiTF-RCC.