Classical pathology versus molecular pathology in renal cell carcinoma

Renal cell carcinoma (RCC) has been characterized based on histology, stage, and grading to predict behavior and guide therapy; however, RCC is still unpredictable, with poor prognosis in metastatic disease. The classification of RCC has been revised to account for molecular characteristics, and there has been an increasing understanding of the hereditary forms of RCC. This has led to further elucidation of pathways in the development of RCC including the hypoxia-inducible pathway and angiogenesis. Many other promising molecular modalities are in development, including gene expression profiling, nuclear parameters, and proliferation/apoptotic markers. This article discusses the current understanding of the classical pathologic features of RCC and highlights recent developments in the cellular and molecular characterization of RCC, which aim to improve the classification, prognostication, and treatment of RCC.