What are the essential features of renal neoplasms based on the current (2004) WHO classification system? What is the clinical implication of the new classification? How does the Fuhrman grading system work? What are the factors affecting survival of renal cell carcinoma patients?

Abstract

Renal cell neoplasms are classified histologically into several types (Table 2-1-1). The four most common types of renal cell neoplasms are clear cell (51%–83%), papillary (11%–20%), and chromophobe (4%–6%) renal cell carcinomas (RCCs) and (benign) oncocytoma (4%–8%). Uncommon tumors, which account for 5%–10% of renal neoplasms, include collecting duct carcinoma, renal medullary carcinoma, mucinous tubular and spindle cell carcinoma, and unclassifiable carcinoma, which does not fit any defined category. Unclassifiable RCCs and collecting duct carcinoma are the most aggressive followed by, in descending order of aggressiveness, clear cell carcinoma, papillary carcinoma, and chromophobe carcinomas. Factors significantly affecting the cancer-specific survival are pathologic stage, nuclear grade, the presence of tumor necrosis, the histologic tumor type, and the presence of sarcomatoid differentiation.