The category of globally accepted neoplasms of the kidney continues to expand. Recognition of new entities is very important for care of patients and their families. For example, some new entities, such as clear cell papillary renal cell carcinoma and t(6;11) translocation carcinoma, exhibit indolent behavior; others, such as SDHB renal cell carcinomas, are remarkably aggressive, and their correct diagnosis establishes a guarded prognosis and impacts family members as well. It is hoped that this chapter will assist the reader in navigating the diagnostic pitfalls involved in establishing an accurate diagnosis for the many different types of renal neoplasms.