Role of molecular testing in diagnosis of renal neoplasms

The evolving landscape of renal neoplasms is a field that is simultaneously exciting and challenging. Next generation sequencing of renal neoplasms over the past decade has deepened our understanding of the biology underlying various entities and provided greater insight into the complexity and numerous subtypes of therein. These advancements have not only refined our comprehension but have also led to the identification of novel tumors driven by molecular alterations not previously known. This progress represents an exciting landmark moment in the field of renal oncology, but also brings its own set of challenges, such as the need to familiarize oneself with these rare subtypes and the ancillary diagnostic tools necessary for accurate diagnosis. A comprehensive understanding of the pathogenesis and molecular biology is essential for the diagnosis of all tumors, including renal neoplasms, especially when genomic findings play a pivotal role. In this review, we explore the role of molecular testing in the diagnosis of renal tumors, addressing the scope of contemporary diagnostic approaches and their limitations, considerations for molecular testing, and provide a guide to judicious and effective molecular testing in the context of renal neoplasms. Finally, we present clinical case-based scenarios that illustrate how molecular results are incorporated into pathology reports to achieve an integrated diagnosis. Key points for each section are summarized into tables for ease of reference.