Glossary of Medical Terms

A product that is added to the diet. A dietary supplement is taken by mouth, and usually contains one or more dietary ingredient (such as vitamin, mineral, herb, amino acid, and enzyme). Also called nutritional supplement.

A synthetic form of the hormone estrogen that was prescribed to pregnant women between about 1940 and 1971 because it was thought to prevent miscarriages. Diethylstilbestrol may increase the risk of uterine, ovarian, or breast cancer in women who took it. It also has been linked to an increased risk of clear cell carcinoma of the vagina or cervix in daughters exposed to diethylstilbestrol before birth. Also called DES.

A health professional who has special training in diet and nutrition. Dietitians advise on nutrition and healthy eating to help prevent and treat conditions, such as food allergies and conditions caused by diabetes, heart disease, and cancer. Dietitians may provide nutritional counseling, meal planning, medical nutrition therapy (such as a special diet, dietary supplements, or intravenous or tube feedings), and nutrition education programs.

A substance that causes a cell to change from an immature form to a mature form. In cancer, a differentiating agent may help cancer cells to become more like normal cells and to grow and spread more slowly. Some differentiating agents are being studied in the prevention and treatment of cancer.

In biology, describes the processes by which immature cells become mature cells with specific functions. In cancer, this describes how much or how little tumor tissue looks like the normal tissue it came from. Well-differentiated cancer cells look more like normal cells and tend to grow and spread more slowly than poorly differentiated or undifferentiated cancer cells. Differentiation is used in tumor grading systems, which are different for each type of cancer.

A serious side effect that may occur in patients with acute promyelocytic leukemia or other types of acute myeloid leukemia who have been treated with certain types of anticancer drugs. Differentiation syndrome usually occurs within 1 to 2 weeks after starting treatment, but it can occur later. It is caused by a large, rapid release of cytokines (immune substances) from leukemia cells that are affected by the anticancer drugs. Signs and symptoms of differentiation syndrome include fever; cough; trouble breathing; weight gain; swelling of the arms, legs, and neck; build-up of excess fluid around the heart and lungs; low blood pressure; and kidney failure. Differentiation syndrome can be life-threatening if not treated early.

Widely spread; not localized or confined.

A childhood condition in which abnormal tissue grows on the outer part of one or both kidneys. Diffuse hyperplastic perilobar nephroblastomatosis usually develops into Wilms tumor (a type of childhood kidney cancer) if not treated. Also called DHPLN.

A rare, fast-growing tumor that forms in cells called glial cells in a part of the brain stem called the pons. Diffuse intrinsic pontine gliomas tend to spread to nearby tissue and other parts of the brain stem, are hard to treat, and have a poor prognosis (outcome). They usually occur in children. Also called DIPG.

A type of B-cell non-Hodgkin lymphoma (cancer of the immune system) that is usually aggressive (fast-growing). It is the most common type of non-Hodgkin lymphoma, and is marked by rapidly growing tumors in the lymph nodes, spleen, liver, bone marrow, or other organs. Other symptoms include fever, night sweats, and weight loss. There are several subtypes of diffuse large B-cell lymphoma.