According to the Mayo Clinic, a high level of epithelial cells that are revealed in a urinalysis sample can be an indication of a tumor. More commonly, a high count of these cells in a urine test indicates that the urine sample has been contaminated.
If a high level of epithelial cells are discovered, the urinalysis needs to be repeated with a new urine sample in order to determine if the first sample was in fact contaminated, according to the Mayo Clinic. Epithelial cells are the cells that form the lining of the body's hollow organs. These cells also form the skin.