TFE3-Rearranged and TFEB-Altered Renal Cell Carcinomas: Molecular Landscape and Therapeutic Advances.

Renal cell carcinomas (RCCs) driven by TFE3 rearrangement or TFEB alteration (MiT-RCC) account for up to 40% of pediatric RCCs but are rare in adults. MiT-RCC includes fusion-driven tumors with TFE3 or TFEB rearrangements (translocation RCC, tRCC) and TFEB-amplified RCC. Morphologic heterogeneity and historical exclusion from trials have limited evidence-based management. We reviewed the literature through January 2026 to summarize molecular biology, pathology, clinical behavior, and systemic therapy. MiT-RCC comprises biologically distinct entities: TFEB-rearranged tumors are often indolent in younger patients, whereas TFEB-amplified RCC, frequently co-amplifying VEGFA, behaves aggressively in older adults. In TFE3-rearranged RCC, fusion partner influences prognosis. Paradoxically, ASPSCR1::TFE3 fusions have the poorest natural history, yet fusion-annotated cohorts suggest these tumors may derive particular benefit from immune checkpoint inhibitor (ICI) plus VEGF receptor tyrosine kinase inhibitor (VEGFR-TKI) combinations. Diagnostic advances including GPNMB immunohistochemistry, TRIM63 RNA in situ hybridization, and sequencing-based fusion panels improve detection of cryptic alterations. First-line ICI + VEGFR-TKI combinations are increasingly favored for metastatic tRCC in eligible patients, while optimal management of TFEB-amplified RCC remains uncertain.