Since the initial recognition of unique renal cell carcinomas (RCC) with the ASPCR1::TFE3 gene fusion, the category of MiT-family RCC has evolved to include TFE3 -rearranged RCC, TFEB -rearranged RCC, and TFEB -amplified RCC, 3 entities with significant intracategory and intercategory variation in morphology and clinical behavior. Given their ability to mimic one another as well as more common RCC subtypes, we present a review here that summarizes relevant morphologic, immunohistochemical, and molecular findings as well as a practical approach to diagnosis. Accurate diagnosis of TFE-altered RCCs is critical to provide patients and treating clinicians with pertinent prognostic information and inform treatment decisions in the event of advanced disease.
Przybycin et al. (Fri,) studied this question.