Youssef YM, White NM, Grigull J et al.
University of Toronto, Toronto, ON, Canada.
Eur Urol 2011;59:721–30.
Editor’s note: Renal cell carcinoma (RCC) is a heterogeneous cancer composed of a number of subtypes, including clear-cell, papillary, chromophobe, and collecting duct tumors, as well as oncocytomas. Each of these subtypes is biologically unique, has a different prognosis, and requires different management. Thus, accurate classification of RCC is important; however, the difficulties in achieving this, even for experienced pathologists, are well recognized (Pathology 2010;42:374–83, Adv Anat Path 2011;18:120–32, Path Res Pract 2009;205:27–34). A small but significant number of RCC tumors are currently unclassifiable based on morphology alone.