ABSTRACT
INTRODUCTION Renal cell carcinomas (RCC) represent 2-3% of all adult cancers diagnosed. Overall, RCCs account for approximately 24 000 new cases and 10 000 deaths annually in the USA with the highest prevalence observed in the 50-60-year age group, and a male:female ratio of approximately 2:1. Occupational exposure to hydrocarbons (trichloroethylene) has been associated with an increased risk of RCC in large epidemiological studies, whereas cigarette smoking is a positive risk factor for non-occupationassociated RCC development. Additional risk factors include hypertension and obesity, and there is an increased risk in patients with end-stage renal failure.1,2
THE PATHOLOGICAL AND GENETIC CLASSIFICATION OF ADULT RENAL EPITHELIAL NEOPLASMS Recent years have seen considerable reorganization in the histological classification of adult renal epithelial neoplasms, culminating in the publication of generally agreed diagnostic categorizations.3-5 This classification is based on our increased understanding of the molecular pathology of renal neoplasms, the close correlation between specific genetic abnormalities and identifiable histological subgroups of renal neoplasms, and the prognostic utility of these subgroupings.6,7
This new classification has been generally accepted because, in the majority of cases, an accurate pathological diagnosis can be made by routine histopathological techniques, with more specialized
molecular genetic studies reserved for a minority of cases. The current classification (summarized in Table 22.1), around which this review is organized, moves away from older classifications of renal epithelial neoplasia, which were essentially a discussion of renal adenocarcinoma and its architectural and cytological subtypes.8
