DCIS: See ductal carcinoma in situ.

Deoxyribonucleic acid (DNA): A long molecule that contains genetic information in all living cells.

Detection: Finding disease. Early detection means that the disease is found at an early stage, before it has grown large or spread to other sites. (Many forms of cancer can develop to an advanced stage without causing symptoms. Because of this, ovarian and pancreatic cancers, for example, are very difficult to detect). Women participate in early detection by performing monthly breast self-examination and getting medical attention for lumps or abnormalities in the breast, by having clinical breast exams by a health professional, and by having mammograms once they reach 40 years of age. Mammography is the principal way to detect breast cancer early. A mammogram can show a developing breast tumor before it can be felt by the woman herself or even by a highly skilled health care professional.

Diagnosis: Identifying a disease by its signs, symptoms, imaging procedures, and/or laboratory findings. In general, the earlier a diagnosis of cancer is made, the better the chance for long-term survival.

Diagnostic mammography: An x-ray examination of the breast in a woman who either has a breast complaint (for example, a breast lump found during self-exam or nipple discharge) or has had an abnormality found during screening mammography. Diagnostic mammography is more involved and time-consuming than screening mammography and is used to determine exact size and location of breast abnormalities and to image the surrounding tissue and lymph nodes. Typically, several additional views of the breast are imaged and interpreted during diagnostic mammography.  See also mammography.

Digital mammography: Digital mammography uses essentially the same mammography system as conventional mammography, but the system is equipped with a digital receptor and a computer instead of a film cassette. Digital mammography provides many benefits over standard mammography equipment, including faster image acquisition, shorter exam time, easier image storage, physician manipulation of breast images for more accurate detection of breast cancer, and transmittal of images over phone lines or a network for remote consultation with other physicians. Currently, only one digital mammography system is FDA approved and is not yet widely available.  Many physicians predict increased use of digital mammography in the future.

Dimpling: A pucker or indentation of the skin; on the breast, it may be a sign of cancer.

Diuretic: Drugs that help the body get rid of excess water and salt.

Discharge (nipple): Any fluid coming from the nipple.  It may be clear, milky, blood, tan, gray, or green. White, yellow, or green nipple discharges are usually benign.  Bloody, watery, red, pink, brown, or black nipple discharge may indicate malignancy.  Nipple discharge should be evaluated by a physician. 

Dissection: Surgery to divide, separate, or remove tissues. (See also axillary dissection).

DNA: Abbreviation for deoxyribonucleic acid. DNA holds genetic information on cell growth, division, and function.

Docetaxel: Brand name, Taxotere. Drug used to treat metastatic breast cancer in patients who have not responded well to standard chemotherapy. Docetaxel inhibits the division of breast cancer cells by acting on the cell's internal skeleton.

Double tier scarring: Term used to describe a standard scar that appears on the breast after TRAM flap breast reconstruction.  See also TRAM flap.

Doubling time: The time it takes for a cell to divide and double itself. The doubling time of breast cancer cells depends on many things, such as the type of tumor, the resistance of the individual's body, and the location in which it tries to grow. A single cell needs 30 doublings to reach noticeable size (1 cm) of a billion cells. Cancers vary in doubling time from 8 to 600 days, averaging 100 to 120 days. Thus, a cancer may be present for many years before it can be felt. (See also cell).

Duct: A hollow passage for gland secretions. In the breast, a passage through which milk passes from the lobule (which makes the milk) to the nipple.

Duct ectasia: Widening of the ducts of the breast, often related to breast inflammation called periductal mastitis. Duct ectasia is a benign (not cancerous) condition. Symptoms of this condition are nipple discharge, swelling, retraction of the nipple, or a lump that can be felt.

Ductal carcinoma in situ (DCIS): Cancer cells that start in the milk passages (ducts) and have not penetrated the duct walls into the surrounding tissue. This is a highly curable form of breast cancer that is treated with surgery or surgery plus radiation therapy. Also called intraductal carcinoma.

Ductogram: See galactogram.

Dysplasia: A group of cells that are abnormal in size, shape, appearance, and organization, but which are not yet cancerous.  

Updated: August 2006