“You have a tumor” is not something anyone wants to hear. But if a doctor does tell you that you do have one, don’t automatically assume that you have cancer. In fact, many kinds of tumors are noncancerous—and some are perfectly harmless and unlikely to interfere with your health at all.

The term tumor, from the Latin word for “swelling,” refers to a mass or growth of tissue. Tumors can form anywhere on or in your body…vary in size and composition (solid, fluid-filled or a combination of both)…and they can vary in their potential to become cancerous. According to some research, the larger a tumor is, the more likely it is to be or become malignant.

Tumors fall into three general categories…

Benign.  The definition of a benign tumor is that it is nonprogressive—meaning that it is not a kind of tumor that invades tissue in other parts of the body (metastasizes). However, even if they aren’t dangerous in and of themselves, some benign tumors can cause health problems, including serious ones, if they grow in a sensitive area, such as in the brain, or if they press on nerves. Examples of benign tumors…

  • Fibroids, which grow in connective tissue, such as uterine fibroids.
  • Adenomas, which grow in glandular tissue, such as colon polyps.
  • Hemangiomas, which are a clump of blood cells, usually on the skin’s surface, such as strawberry marks.
  • Lipomas, which are growths of fatty tissue under the skin, are common in middle age and are never cancerous—although they can press on nerves or muscle and cause discomfort.

Premalignant. Abnormal growths that aren’t currently cancerous but that have the potential to become so are called premalignant. Examples include…

  • Actinic keratosis: Growths on the skin that are usually scaly and thick and can become skin cancer.
  • Cervical dysplasia: Growths of abnormal cells on the cervix that can become cervical cancer.
  • Lung metaplasia: Growths of abnormal cells in the lungs that can become lung cancer.
  • Leukoplakia: Patches of abnormal growths inside the mouth that can become different types of mouth or gum cancer.

Malignant. Tumors that are malignant are in fact cancer. The cells of these tumors grow and divide rapidly and can spread to and invade other tissues or areas of the body, a process that is called metastasis. Examples

  • Carcinoma: A tumor in the skin or in tissue that surrounds internal organs.
  • Sarcoma: A tumor in the bone, fat, muscle tissue or other body tissues other than organs.
  • Leukemia: A malignancy in tissues that manufacture blood cells, such as bone marrow, causing an overproduction of abnormal blood cells.
  • Lymphoma or multiple myeloma: Tumors that start in cells of the immune system. Specifically, multiple myelomas are malignant plasma cells.
  • Central nervous system cancers: Tumors that start in the brain or spinal cord.

Hopefully, if you’re diagnosed with a tumor it will be of the harmless variety. In the meantime, there are a lot of things you can do to reduce your chance of getting cancer. Reading Bottom Line’s Guide to 20 Proven Ways to Stay Cancer-Free is a good place to start!