If a cyst does not go away, the doctor may suggest removing it, especially if it is causing problems or seems to be changing. In some cases, the doctor may decide to wait and watch for changes with ultrasonography or other tests. Malignant tumors are cancer. Cancer cells can invade and damage tissues and organs near the tumor. Also, cancer cells can break away from a malignant tumor in the ovary and spread to other organs in the abdomen and form new tumors.
Ovarian cancer spreads most often to the colon , the stomach, and the diaphragm .
The cancer cells also can enter the lymphatic system or the bloodstream and spread to other parts of the body. The spread of cancer is called metastasis . There are several types of ovarian cancer. Most ovarian cancers are epithelial carcinomas , which begin in the lining of the ovary. For example, ovarian cancer that spreads to the colon is metastatic ovarian cancer.