• Malignant – Malignant means that a tissue has cancer cells present; it also refers to a cancerous disease.
  • Mastectomy – Surgical removal of breast tissue. There are several different types of mastectomies: modified radical mastectomy, partial mastectomy, simple mastectomy, and prophylactic mastectomy.
  • Melanoma – A cancer that starts in the skin cells. Melanoma is more serious than other cancers of the skin because it spreads easily to other cells in the body. Symptoms include changes in size, shape, or color of a mole; bleeding from a mole; or a mole that feels itchy, hard, lumpy, swollen, or tender to the touch. Melanoma can also appear on the body as a new mole.
  • Metastasis – The spread of cancer from one part of the body to another.
  • MRI – Magnetic resonance imaging, or MRI, creates three-dimensional sectional images similar to CT scanning. An MRI differs from a CT scan in that it does not use ionizing radiation, but instead uses a powerful magnet to transmit radio waves through the body. Images then appear on a computer screen. Doctors use MRI to diagnose and stage cancer. A contrast medium may be used in MRI imaging to enhance the picture.
  • Mucositis – Inflammation of the lining of the gastrointestinal tract. Oral mucositis refers to inflammation of the lining of the mouth. Mucositis may involve sores, swelling, pain, and redness.
  • MUGA scan – A multigated acquisition scan, MUGA scan, is a procedure that allows a physician to examine the heart. Special pictures are taken of the heart following the introduction of a radioactive substance into a vein. Your doctor can then visualize the contraction and relaxation of the heart and blood supply to the heart.
  • Myelosuppression – Myelosuppression occurs when the bone marrow slows production of blood cells. This results in fewer red blood cells, white blood cells, or platelets available to perform their normal functions in the body. Chemotherapy can cause decreased bone marrow function. Most often, myelosuppression refers to the loss of white blood cells.