Renal cell carcinomas (RCCs) are heterogeneous group of cancers that arise from the tubuler cells and are responsible for 80-85% of all primary renal neoplasms. Less than 5% of all RCCs are thought to be due to a hereditary syndrome. Family studies and molecular genetics have provided important insights into the molecular pathways underlying the pathogenesis of RCCs as well as new insights into classification of RCC. Morphologically based classification of RCCs has evolved over the last 3 decades with the incorporation of molecular genetics into the diagnostic features RCCs. The most recent 2012 Vancouver classification recognized the newly established entities tubulocystic RCC, acquired cystic disease-associated RCC, clear cell (tubulo) papillary RCC, microphthalmia transcription factor family translocation RCC and hereditary leiomyomatosis RCC syndrome-associated RCC. In this article, the molecular and genetic properties of RCCs were summarized and the mechanisms underlying the development new entities of RCCs were discussed. The use of immunohistochemistry and molecular techniques were also evaluated in establishing an accurate diagnosis in new entities.

Keywords: Renal carcinoma, renal cell carcinoma, classification