Medical Glossary D
Dermatologist (der-ma-TOL-o-jist): A doctor who specializes in the diagnosis and treatment of skin problems.
Dermis (DER-mis): The lower or inner layer of the two main layers of cells that make up the skin.
Diabetes (dye-a-BEE-teez): A disease in which the body does not use sugar properly. (Many foods are converted into sugar, a source of energy for cells.) As a result, the level of sugar in the blood is too high. This disease occurs when the body does not produce enough insulin or does not use it properly.
Diagnosis: The process of indentifying a disease by the signs and symptoms.
Dialysis (dy-AL-i-sis): The process of cleansing the blood by passing it through a special machine. Dialysis is necessary when the kidneys are not able to filter the blood.
Diaphanography (DY-a-fan-OG-ra-fee): An exam that involves shining a bright light through the breast to reveal features of the tissues inside. This technique is under study; its value in detecting breast cancer has not been proven. Also called transillumination.
Diaphragm (DY-a-fram): The thin muscle below the lungs and heart that separates the chest from the abdomen.
Diathermy (DIE-a-ther-mee): The use of heat to destroy abnormal cells. Also cauterization or electrodiathermy.
Diethylstilbestrol (die-ETH-ul-stil-BES-trol): A drug that was once widely prescribed to prevent miscarriage. Also called DES.
Differentiation: In cancer, refers to how mature (developed) the cancer cells are in a tumor. Differentiated tumor cells resemble normal cells and grow at a slower rate than undifferentiated tumor cells, which lack the structure and function of normal cells and grow uncontrollably.
Digestive system: The organs that take in food and turn it into products that the body can use to stay healthy. Waste products the body cannot use leave the body through bowel movements. The digestive system includes the salivary glands, mouth, esophagus, stomach, liver, pancreas, gallbladder, intestines, and rectum.
Digestive tract (dye-JES-tiv): The organs through which food passes when we eat. These are the mouth, esophagus, stomach, small and large intestines, and rectum.
Digital rectal exam: An exam to detect cancer. The doctor inserts a lubricated, gloved finger into the rectum and feels for abnormal areas. Also called DRE.
Dilation and Curettage (di-LAY-shun and KYOO-re-tahzh): A minor operation in which the cervix is expanded enough (dilation) to permit the cervical canal and uterine lining to be scraped with a spoon-shaped instrument called a curette (curettage). This procedure also is called D and C.
Dilator (DIE-lay-tor): A device used to stretch or enlarge an opening.
Douching (DOO-shing): Using water or a medicated solution to clean the vagina and cervix.
Dry orgasm: Sexual climax without the release of semen.
Duct (dukt): A tube through which body fluids pass.
Ductal carcinoma in situ (DUK-tal kar-sin-O-ma in SY-too): Abnormal cells that involve only the lining of a duct. The cells have not spread outside the duct to other tissues in the breast. About 15%-20% of breast cancers are sometimes called carcinoma in situ. They may be either ductal carcinoma in situ (sometimes called intraductal carcinoma) or lobular carcinoma in situ. Even though it is referred to as a cancer, it is not actually cancer. However, patients with this condition have a 25% chance of developing breast cancer in either breast in the next 25 years. Also called DCIS or intraductal carcinoma.
Dumping syndrome: A group of symptoms that occur when food or liquid enters the small intestine too rapidly. These symptoms include cramps, nausea, diarrhea, and dizziness.
Duodenum (doo-o-DEE-num): The first part of the small intestine.
Dysplasia (dis-PLAY-zha): Abnormal cells that are not cancer.
Dysplastic nevi: (dis-PLAS-tik NEE-vye): Atypical moles; moles whose appearance is different from that of common moles. Dysplastic nevi are generally larger than ordinary moles and have irregular and indistinct borders. Their color often is not uniform, and ranges from pink or even white to dark brown or black; they usually are flat, but parts may be raised above the skin surface.