A layer of cells that line the skin, intestines, lung, stomach, bowels, or breast lobules are called epithelial cells.
About 80 of all cancers are carcinomas. Much of the time, the words carcinoma and cancer are used interchangeably, since they often refer to the same condition.
If cancer is found in the connective tissue instead of epithelial tissue, then it is called sarcoma. If cancer cells are found in the white blood cells, it is called leukemia.