The term "ovarian cancer" includes several different types of cancer that all arise from cells of the ovary. Most commonly, tumors arise from the epithelium, or lining cells, of the ovary. These include epithelial ovarian (from the cells on the surface of the ovary), fallopian tube, and primary peritoneal (the lining inside the abdomen that coats many abdominal structures) cancer. These are all considered to be one disease process. There is also an entity called borderline ovarian tumors that have the microscopic appearance of a cancer, but tend not to spread much.
However, there are also less common forms of ovarian cancer that come from within the ovary itself, including germ cell tumors and sex cord-stromal tumors. All of these diseases will be discussed, as well as their treatment.