Types of Renal Cell Carcinoma
Numerous types of renal cell carcinoma exist, but there are five main types. A surgical biopsy and subsequent microscopic examination are required to determine the type of renal cell cancer. Some patients may have a combination of two or more types. The types of renal cell carcinoma are:
- Clear cell renal carcinoma – This is the most common type of renal cell carcinoma, accounting for 80 percent of the cases. The tumors associated with this type appear pale or very clear.
- Papillary renal carcinoma – This is the second most common type of renal cell carcinoma. It accounts for 10-15 percent of the cases. Finger-like projections, called papillae, form in part or the entire tumor. This type is also referred to as chromophilic (readily stained with dye) because the cells absorb certain dyes used to prepared the tissues and appear pink under a microscope.
- Chromophobe renal carcinoma – As the third most common type of renal cell carcinoma, chromophobe makes up five percent of the cases. The cancer cells are very pale, much like the clear cell renal carcinoma, but are much larger.
- Collecting duct renal carcinoma – This is an extremely rare type of renal cell carcinoma. The cancer cells form irregular tubes within the tumor.
- Unclassified renal carcinoma – Five percent of renal cell carcinoma cases do not fit into the other four categories. They are lumped into an unclassified category.