Molecular Pathogenesis of Renal Neoplasms in Patients with Birt–Hogg–Dubé Syndrome

Birt–Hogg–Dubé syndrome (BHDS) is an autosomal dominant disease characterized by skin, lung, and renal manifestations. This syndrome is caused by a germline mutation in the FLCN gene, which leads to disruption in multiple downstream pathways. Renal cell carcinomas are one of the serious clinical manifestations of the disease, which usually presents as bilateral and multiple tumors. Morphologically, most of these tumors are classified as hybrid oncocytic tumors. Recent advances in molecular techniques have shed light on the pathogenesis of these renal tumors. In this review, we evaluate and summarize the current knowledge of BHDS, pathologic changes, and its molecular basis with the focus on the renal hybrid oncocytic tumor (HOT), their pathogenesis, and molecular underpinning.