Most important, benign tumors are rarely a threat to life. Malignant tumors are cancer. Cells in malignant tumors are abnormal and divide without control or order. These cancer cells can invade and destroy the tissue around them. This process, called metastasis, is how cancer spreads from the original tumor to form new tumors in other parts of the body.
Cancer can cause a variety of symptoms.
When these or other symptoms occur, they are not sure signs of cancer. Symptoms may be caused by infections, benign tumors, or other problems. It is important to see a doctor if you have any of these symptoms or if you are concerned about other changes in your body or the way you feel. Only a doctor can make a diagnosis. A biopsy is the most reliable way to know whether a medical problem is cancer.