Glossary of Cancer Terms

   

M proteins

A monoclonal imunoglobulin protein, produced by plasma cell neoplasms ranging from diseases such as essential monoclonal gammopathy to multiple myeloma.

Macrocalcification

Coarse calcium deposits. They are most likely due to aging, old injuries, or inflammations and usually are associated with benign conditions.

Magnetic resonance imaging (MRI)

A procedure in which a magnet linked to a computer is used to create detailed pictures of areas inside the body.

Maintenance therapy

Chemotherapy given while a patient is in remission to prevent a relapse.

Malignant

Cancerous, a growth that tends to invade and destroy nearby tissue. Malignant growths can spread to other parts of the body.

Malignant Fibrous Histiocytoma (MFH) The term is used to describe a group of malignant soft tissue tumors with a fibrohistiocytic appearance. It is the most commonly diagnosed extremity sarcoma. Characteristically MFH is a tumor of later adult life with a peak incidence in the seventh decade, although it may occur in younger adults. Usually presents as a painless mass; the most common site is the lower extremity.

Mammogram

An x-ray of the breast.

Mammography

The use of x-rays to create a picture of the breast. Used to diagnose a variety of breast problems.

Mastectomy

Surgery to remove the breast (or as much of the breast tissue as possible).

Mastitis

Infection of the breast tissue.

Medical oncologist

A doctor who specializes in the treatment of cancer using chemotherapy, hormonal therapy, and biological therapy. They also have expertise in handling the general medical problems that arise during the course of the disease.

Medical risk factor

Health conditions that may lead to cancer. See colon polyps.

Medulloblastoma (MDL)

A fast-growing, invasive tumor which frequently spreads to other parts of the central nervous system via the spinal fluid. The MDL is always located in the cerebellum. They represent 15-20% of pediatric brain tumors. 30% of these tumors occur in adults.

Melanin

The pigment which gives color to hair, skin, and the choroid of the eye. Exposure to sunlight stimulates melanin production.

Melanocytes

Cells in the skin that produce and contain the pigment called melanin.

Melanoma

Cancer that arises in melanocytes, the cells that produce pigment. Melanomas are the most malignant form of skin cancer. Melanomas are most commonly found on the skin, but 10 percent arise in the eye.

Membrane

A thin, soft, pliable layer of tissue which lines a tube or cavity, covers an organ or structure, or separates one part from another.

MEN-1 (Werner's syndrome) Multiple endocrine neoplasia (abnormal and uncontrolled cell growth) syndromes are familial disorders that include cancerous changes in more than 1 endocrine organ at the same time (endocrine tissue secretes hormones). These changes may include hyperplasia (overgrowth of tissue) or benign (noncancerous) tumors. The distinct involvement of multiple glandular structures are referred to as MEN-1 (Werner's syndrome) which may involve tumors of the pituitary gland and parathyroid, adrenal, gastric, and pancreatic structures.
MEN-2a (Sipple syndrome) A multiple endocrine neoplasm which is associated with medullary thyroid carcinoma, parathyroid hyperplasia, and adenomas as well as pheochromocytoma. Multiple endocrine neoplasia (abnormal and uncontrolled cell growth) syndromes are familial disorders that include cancerous changes in more than 1 endocrine organ at the same time (endocrine tissue secretes hormones). These changes may include hyperplasia (overgrowth of tissue) or benign (noncancerous) tumors.
MEN-2b A multiple endocrine neoplasm which is associated with medullary thyroid carcinoma, parathyroid hyperplasia, and adenomas as well as pheochromocytoma, mucosal neuromas, and ganglioneuromas. Multiple endocrine neoplasia (abnormal and uncontrolled cell growth) syndromes are familial disorders that include cancerous changes in more than 1 endocrine organ at the same time (endocrine tissue secretes hormones). These changes may include hyperplasia (overgrowth of tissue) or benign (noncancerous) tumors.

Meninges

The three membranes that cover and protect the brain and spinal cord.

Meningioma

Brain tumors that arise from the arachnoid cells of the meminges of the brain and spinal cord. They represent about 20% of all primary brain tumors and occur most commonly in middle-aged women. The majority of meningiomas are benign,however they can recur, sometimes as a higher grade tumor.

Menopause

The period of time which marks the permanent cessation of menstrual activity. This occurs between the ages of 35 and 58 years of life.

Menstrual cycle

The periodically recurrent series of changes occurring in the uterus and associated sex organs (ovaries, cervix and vagina) associated with menstruation and the time in between. The human cycle averages 28 days in length, measured from the beginning of menstruation.

Menstruation

The periodic discharge of bloody fluid from the uterus occurring at more or less regular intervals during the life of a woman from age of puberty to menopause.

Merkle Cell Cancer (MCC) A potentially aggressive skin tumor of neuroendocrine cell origin. Though it primarily affects the head and neck, other areas may be involved. MCC affects more men than women and most often occurs between the seventh and ninth decades.
Mesothelioma A malignant tumor in the lining of the chest and abdominal cavities. It is a rare form of cancer. Most people who develop this cancer have a history of exposure to the widely found carcinogen asbestos.
Mesothelium The thin lining on the surface of the body cavities and the organs that are contained within them.

Metastasis, metastatic, metastasize

The spread of cancer from one part of the body to another. When cancer cells metastasize and form secondary tumors, the cells in the metastatic tumor are like those in the original (primary) tumor.

Metastatic brain tumors Cancer that begins in other parts of the body may spread to the brain and cause secondary tumors. These tumors are not the same as primary brain tumors. Cancer that spreads to the brain is the same disease and has the same name as the original (primary) cancer. For example, if lung cancer spreads to the brain, the disease is called metastatic lung cancer because the cells in the secondary tumor resemble abnormal lung cells, not abnormal brain cells.
Metastatic Breast Cancer Breast cancer that has spread to other organs of the body, the most common sites for metastasis of breast cancer is to the bone, lung, liver, or brain. Also relates to skin and chest wall involvement beyond the breast area.

Metastatic Cancer

Cancer that has spread from its original site to one or more additional body sites.

Microcalcifications

Tiny deposits of calcium in the breast that are usually seen only on a mammogram. When clustered can be a sign that cancer is present.

Modified radical mastectomy

Surgery to remove the breast, and some of the lymph nodes under the arm. The underlying chest muscles are left in place.

Mole

A benign growth on the skin (usually tan, brown or flesh colored) that contains a cluster of melanocytes and surrounding supportive tissue.

Monoclonal antibodies

Laboratory produced substances that can locate and bind to cancer cells wherever they are in the body. Many monoclonal antibodies are used in cancer detection or therapy; each one recognizes a different protein on certain cancer cells. Monoclonal antibodies can be used alone, or they can be used to deliver drugs, toxins, or radioactive material directly to the tumor.

Mouth The opening through which food passes into the body enclosing the tongue, gums and teeth.

Mucositis

Inflammation of the mucous membranes. Soreness can develop in the mouth as a side effect of chemotherapy.

Multimodality therapy

The combined use of more than one method of treatment, for example surgery and chemotherapy.

Multiple Endocrine Neoplasm Multiple endocrine neoplasia (abnormal and uncontrolled cell growth) syndromes are familial disorders that include cancerous changes in more than 1 endocrine organ at the same time (endocrine tissue secretes hormones). These changes may include hyperplasia (overgrowth of tissue) or benign (noncancerous) tumors. The distinct involvement of multiple glandular structures are referred to as MEN-1 (Werner's syndrome) which may involve tumors of the pituitary gland and parathyroid, adrenal, gastric, and pancreatic structures. MEN-2a (Sipple syndrome) is associated with medullary thyroid carcinoma, parathyroid hyperplasia, and adenomas as well as pheochromocytoma; MEN-2b is associated with medullary thyroid carcinoma, parathyroid hyperplasia, and adenomas as well as pheochromocytoma, mucosal neuromas, and ganglioneuromas. An additional complex is referred to as the Carney complex, which is associated with heart and skin tumors.

Multiple Myeloma

Multiple myeloma is one of the several diseases that fall under the category of plasma cell dyscrasia. The disease results from an abnormality of the plasma cell. The plasma cell is part of the immune system that is responsible for forming antibodies against foreign organisms and substances that invade the body. The disease process occurs when one of these cells escapes from the control of the master immune system and behaves erratically by forming dysfunctional antibodies and dividing into numerous cells that the body does not need.

Mutation

A change in the number, arrangement, or molecular sequence of a gene.

Mycosis Fungoides (Cutaneous T-Cell Lymphoma – CTCL) Neoplasms of the T lymphocytes which affect the skin. Mycosis fungoides, Se'zary syndrome, and reticulum cell sarcoma of the skin are all different clinical presentations of CTCL. CTCL is a relatively rare neoplasm. The incidence rises with age and the majority of those affected are between 40 and 60 years old. It is more common in males than in females.

Myelin

The fatty substance that covers and protects nerves.

Myelodysplastic Syndrome

A condition in which the bone marrow does not function normally and can effect the various types of blood cells produced in the bone marrow. Often referred to as a preleukemia and may progress and become acute leukemia. Treatment depends on the overall goal at a given point in the course of the disease and can range from observation to bone marrow transplantation.

Myelogenous

Producing or originating in the bone marrow.

Myelogram

An x-ray of the spinal cord and the bones of the spine by use of a radiopaque medium injected into the intrathecal space.

Myeloid Resembling a myelocyte, a type of white blood cell, but not necessarily originating from bone marrow.

Myometrium

The muscular wall of the uterus.

 

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