Renal pelvis tumors are rare kidney cancers appearing in a specific part of the kidney known as the pelvis of the kidney.
The word renal means having to do with the kidneys. A part of each kidney in the human body is called the renal pelvis. The renal pelvis in each kidney is the portion of the collecting system of the kidney that empties into the ureters (tubes that carry urine from the kidneys to the bladder). Tumors of the renal pelvis are rare.
A transitional cell is intermediate between the flat squamous cell and the tall columnar cell. It is restricted to the epithelium (cellular lining) of the urinary bladder, ureters, and the renal pelvis. Transitional cell carcinomas have a wide range in their gross appearance depending on their locations. Some of these carcinomas are flat in appearance, some are papillary (small elevation), and others are in the shape of a node. Under the microscope, however, most of these carcinomas have a papillary-like look. There are three generally recognized grades of transitional cell carcinoma. The grade of the carcinoma is
determined by particular characteristics found in the cells of the tumor. Transitional cell carcinoma typically affects the mucosa (the moist tissue layer that lines hollow organs or the cavity of the body) in the areas where it originates— in this case, the kidney.
Bob Kirsch, The Gale Group Inc., Gale, Detroit,