Macroglobulinaemia

A macroglobulin is a large protein molecule, such as an antibody. In certain conditions, abnormal lymphocytes produce an excess amount of an abnormal antibody known as IgM. This is called macroglobulinaemia.

Macrophage

A type of white blood cell which leaves the blood and enters into tissues and acts as a scavenger, taking in and destroying particles such as bacteria.

Magnetic resonance imaging (MRI)

A body scanning technique which uses an intense magnetic field to build up a picture of organs inside the body. X-rays show bones clearly but not other tissues, MRI shows all tissues and organs clearly. It can often, but not always, tell the difference between normal and cancerous tissues.

Maintenance treatment

Treatment given for a period of months or years to maintain remission and get rid of any remaining leukaemic cells in the body, usually for acute lymphoblastic leukaemia.

Malignant

A term applied to diseases where there is uncontrolled production of cells. See also cancer and benign.

Megakaryocyte

Large cell in the bone marrow which produces platelets.

Minimal residual disease (MRD)

In cancer treatment, particularly leukaemia, MRD testing has several important roles: determining whether treatment has eradicated the cancer or whether traces remain, comparing the efficacy of different treatments, monitoring patient remission status as well as detecting recurrence of the leukaemia or cancer, and choosing the treatment that will best meet those needs .

Monoclonal

Monoclonal cells are genetically identical cells, all of which come from the same mother cell. When the body responds to an infection it will produce a large number of monoclonal antibody-producing plasma cells. Because they are monoclonal, they all produce an identical antibody.

Monoclonal antibodies

Monoclonal antibodies – a type of protein made in the laboratory that can bind to substances in the body, including cancer cells. There are many kinds of monoclonal antibodies. A monoclonal antibody is made so that it binds to only one substance. Monoclonal antibodies are being used to diagnos and treat some types of cancer. They can be used alone or to carry drugs, toxins, or radioactive substances directly to cancer cells.

Monoclonal gammopathy

A healthy person’s blood contains a mixture of many different antibodies. In some diseases very large amounts of identical antibodies are produced; in these cases the antibodies produced are of no use to help fight infection. This is known as a monoclonal gammopathy (gamma globulin is another name for antibody molecules).

Monoclonal gammopathy of unknown significance (MGUS)

When a person is found to have a monoclonal gammopathy with no clear cause, this is called MGUS. MGUS is important because, although it is not an illness and does not cause any signs or symptoms, people with MGUS have a higher risk of developing myeloma. Each year on average about one in 100 people with MGUS will develop myeloma (or a related condition).

Monocytes

are a type of white blood cell (leukocyte) which is relatively large. They are the largest of all leukocytes and are part of the immune system. It acts as a scavenger and takes in larger bacteria and cell debris.

Monocytes constitute 2% to 10% of all leukocytes in the human body.

Monocytic leukaemia

Cancer of the blood due to overproduction of cells of the monocyte lineage.

Mucositis

Inflammation of the mouth and throat which may be caused by anti-leukaemia drugs.

Multidisciplinary Team MDT

A multidisciplinary team (MDT) is a group of doctors and other health professionals. An MDT will include experts from different fields such as pharmacists, nurses, dietitians. Together they will discuss an individual patient’s care and agree on a treatment plan.

Multi-Drug Resistance (MDR)

Multi-drug resistance occurs when malignant cells become resistant to a wide range of anti-cancer drugs. This usually happens because the cells can get rid of anti-cancer drugs before a high enough concentration to kill the cells is achieved. Resistance against most drugs will make the condition very difficult to treat.

Multiple Myeloma

A cancer caused by uncontrolled production of the white blood cells called plasma cells in the bone marrow. The malignant cells are not usually found in the blood and the tumour growth is restricted to the bones. This will damage bones and cause kidney problems unless it is treated.

Mutation

A minute genetic change to DNA caused, for example, by exposure hazardous chemicals or copying errors during cell division. If these affect normal cell function they can lead to disease development.

 Myeloblastic

Immature myeloid cells.

 Myeloid

Collective term for all blood cells except lymphocytes. It includes granulocytes, monocytes, red cells and platelets.

Myelomonocytic

A condition which affects both the myeloid and monocytic cells.

Myelopoiesis

The process of production and maturation of myeloid cells.