In the past decade, several novel renal neoplasms characterized by mutations in the tuberous sclerosis complex (TSC) or mechanistic target of rapamycin (mTOR) pathway genes in both the sporadic and germline settings have been described. Herein, we review these entities, highlighting their clinical and molecular characteristics.

A spectrum of renal tumors associated with frequent TSC/mTOR (tuberous sclerosis complex/mechanistic target of rapamycin) pathway gene alterations (in both the germline and sporadic settings) have recently been described. These include renal cell carcinoma with fibromyomatous stroma (RCC FMS), eosinophilic solid and cystic renal cell carcinoma (ESC RCC), eosinophilic vacuolated tumor (EVT), and low-grade oncocytic tumor (LOT). Most of these entities have characteristic morphologic and immunohistochemical features that enable their recognition without the need for molecular studies. In this report, we summarize recent advances and discuss their evolving complexity.