DCIS, ductal carcinoma in situ (intraductal carcinoma): Abnormal cells that involve only the lining of a milk duct.

Deoxyribonucleic acid (DNA): A nucleic acid found in the cell nucleus that is the carrier of genetic information and the fundamental component of living matter.

Diagnosis: The term specifying the name of the disease or syndrome that a person has or is believed to have.

Diagnostic mammogram:  A diagnostic mammogram is used to evaluate a woman with symptoms suggestive of breast cancer found during physical examination such as a palpable lump or thickening of breast tissue or when a problem is detected in a screening mammogram , such as a shadow or spot requiring further investigation.

Diaphanography:  Transillumination of the breast.

Differentiated:  Clearly defined.      

Differentiation: The resemblance of cancer cells to normal cells. Well-differentiated tumor cells closely resemble normal cells and are thought to be less aggressive than poorly-differentiated tumor cells.

Diploid: The term used to describe a cell population that contains the normal amount of DNA material.

Disseminated: Term applied to disease organisms scattered or distributed throughout an organ or body.

Dopamine: An important brain neurotransmitter that plays an active role in body movement, primitive drives, sexual behavior, emotions and immune system functioning.

Double-blind study: A study in which neither the researcher nor the subject knows who is getting what treatment. (One of the treatments may be a placebo.)

Doubling time:  The time it takes a cell population to double in number.

Drain:  Tubes or suction devices inserted after a mastectomy or breast reconstruction to drain the fluids that accumulate following surgery.

Duct:  A tubular structure in the breast that milk passes through to the nipple.

Ductal carcinoma in situ (DCIS):  A type of breast cancer found in the breast ducts that has not become invasive.  Also referred to as intraductal carcinoma.

E

Edema:  Excessive accumulation of fluids in tissues, causing swelling.

Endocrine glands:  The glands (such as the adrenal glands, ovaries and pancreas)  that manufacture hormones and release them into the bloodstream.

Endometrium:  The mucous membrane lining the inner surface of the uterus.

Endorphins:  Natural chemical substances, produced in the brain, that act as opiates and produce pain control by binding to opiate receptor sites involved in pain perception.  A personís threshold for pain can be increased by this action.

Enzyme:  A protein/organic catalyst produced by living cells that promotes the chemical processes of life without itself being altered.  Enzymes are capable of accelerating the speed of chemical reactions. They are present in digestive juices, where they act upon food substances causing them to break down into simpler compounds.
  
erb B-2/neu gene or HER-2/neu gene:  Name of oncogene associated with a more aggressive type of breast cancer; these genes have a high growth rate.

Erythrocytes: Red blood cells that carry oxygen from the lungs to cells in all parts of the body, and carry carbon dioxide from the cells back to the lungs.

Estrogen or progesterone receptor (ER/PR) Analysis:  A test used to measure or detect the presence of estrogen or progesterone receptors in a tumor.  The presence or absence of these receptors is important in determining whether or not the cancer is sensitive to estrogen and/or progesterone hormones in the body and whether or not cytotoxic or hormonal therapy will be used.

Excise:  To cut or remove surgically.

Excisional biopsy:  The surgical removal of the entire lump.

F

Fascia:  A fibrous membrane covering, supporting and separating muscles and various organs of the body that attaches the breasts and other body structures to underlying muscles.

Fat necrosis:  A section of dead fat usually resulting from some kind of trauma or surgery that can appear as a thickened area or lump(s).

Fibroadenoma: A non-cancerous (benign) growth found in the breast.  

Fibrocystic breasts:  A benign condition in which there are palpable lumps or cysts in the breasts, commonly associated with pain and tenderness.  This condition fluctuates with a womanís menstrual cycle.

Fibroids:  Fibrous, noncancerous growths most commonly found in or on the uterus.

Fine needle aspiration (FNA):  A biopsy using a thin needle to remove fluid from a cyst or a group of cells from a solid lump.

Flap:  A portion of tissue with its own blood supply moved from one part of the body to another.  Flaps of muscle, fat and skin are often used in reconstructive breast surgery to provide additional tissue for the reconstructed breast.  Common donor sites for flap reconstruction are the abdomen (transverse rectus abdominus musculocutaneous, or TRAM Flap), back (latissimus dorsi flap) and buttocks (gluteus maximus musculocutaneous flap).

Flow cytometry: Analysis of tumor cells performed on biopsy specimens to determine the number of cells that are multiplying in order to determine how fast the tumor is growing.

Follicle-stimulating hormone (FSH):  A hormone secreted by the pituitary gland that stimulates the follicles in the ovary to grow and mature.

Frozen section:  A small piece of a larger piece of tissue removed during a biopsy that is sent to pathology to be frozen for instant analysis to determine if cancer is present.

G

Gene:  A unit of genetic material (DNA) that carries the directions a cell uses to perform a specific function.

Glands: Lymph nodes.

Gluteus maximus musculocutaneous flap:  Reconstructive breast surgery using an autologous flap of tissue (the patientís own tissue) from the buttock area to build a new breast.

Growth rate factors:  Markers used to predict the growth rate of malignant cells and the probability that the cancer will spread.

Guided imagery: Imagining yourself in a story told by someone else.  A flow of thoughts that you can see, hear, feel, smell or taste in your imagination.  

Gynecologist: A doctor who specializes in the care and treatment of women's reproductive systems.

H

Halsted radical mastectomy:  Surgical removal of the breast, skin, pectoralis minor and major muscles, all axillary lymph nodes and fat for the local treatment of breast cancer.  (Rarely done anymore.)

Helper T cells:  A subset of T cells that are essential for turning on antibody production and initiating many other immune responses.

Hematoma:  A collection of blood confined to an organ, tissue or space caused by a break in a blood vessel.  Hematomas can form in a wound after an injury or surgery.

Hematologist:  A specialist in the study of the blood and in the diagnosis and treatment of disorders of blood and blood-forming tissues.

Hemoglobin:  Protein in the blood that contains iron and carries oxygen from the lungs to the tissues.

Hormones:  Chemical substances produced in one part of the body and carried in the blood to another part of the body, where it has specific effects.

Hormone receptor assay:  A diagnostic test to determine if a breast cancerís growth is influenced by hormones and/or can be treated with hormone therapy.

Hormone therapy:  Treatment of cancer to block the ability of hormones to interact with cancer cells.  Tamoxifen is an example of a drug used in hormone therapy.

Hyperplasia:  The excessive formation of cells.