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The glossary below was compiled for us by leading medical textbook author Davi-Ellen Chabner. It is full of useful breast cancer terms and definitions to help patients and caregivers better understand the language they are hearing and reading while going through breast cancer diagnosis and treatment. As always, please consult your physician for more detail and explanation where necessary.


The breasts are composed mostly of mammary glands in a background of supporting (connective) tissue. See diagrams below of the normal anatomy and tissues that are in and around the breast. (Illustrations reprinted here by permission of Davi-Ellen Chabner and Elsevier Publishing.)

BreastAThe milk glands or lobules develop in response to hormones from the pituitary gland and from the ovaries during puberty and expand further during pregnancy.

The pectoralis major is a thick, fan-shaped muscle, situated under the breast in the female. Underneath the pectoralis major is the pectoralis minor, a thin, triangular muscle.

breastdiagramBBreasts also contain special milk ducts that carry milk to the nipple (mammary papilla), which has small openings for the ducts to release milk.

The darkly colored skin surrounding the mammary papilla is the areola.

The underarm or axillary lymph nodes are responsible for draining lymphatic fluid from the breasts and surrounding areas.


Breast cancer is a growth that begins from cells in the breast. It is a disease that occurs in women, but can also occur in men, though with much less frequency.


Breast cancer is the most common kind of cancer that occurs in women, affecting more than 200,000 persons each year. Sensitive detection of breast cancer through routine x-ray tests (mammography) beginning at age 40 has made it possible to discover tumors at an early and curable stage. In most patients the tumor is found as a localized lump in the breast, and the majority of patients will have no recurrence following surgical removal of the tumor, followed by radiation and drug treatment (adjuvant therapy) as necessary. In two-thirds of patients, breast cancers are driven by estrogen hormones, which promote their growth and survival. Hormonal blockers such as tamoxifen and Arimidex are effective in preventing tumor recurrence, and in patients who develop distant spread of disease, hormonal treatments can produce beneficial responses and long term disease control. Chemotherapy with drugs such as paclitaxel (Taxol) and doxorubicin are also effective in adjuvant therapy, following surgery and irradiation, and in treating distant spread of disease. For about 25{80a5668e922b9fd980dde0a6d6f2a27c110d8d696a90e3ef35289df5d75c2aa7} of patients with tumors that express the Her2/neu protein on the tumor surface, a Her 2 blocking antibody, herceptin, greatly augments the effectiveness of chemotherapy. As our understanding of the disordered biology of breast cancers expands, new treatments are being devised to improve the already excellent outlook for most patients, and to reduce or avoid the side effects of current therapy.



Abscess: A collection of pus and sign of infection. Pus contains white blood cells and bacteria. Breast abscesses may be discovered as a tender lump in the breast and may be mistaken for cancer. In rare cases, inflammation of the breast (mastitis) may accompany breast cancer.

Adenocarcinoma: Cancerous tumor (growth) arising from the glandular tissue of the breast. Aden/o means gland, carcin- means cancerous, and -oma means tumor. Adenocarcinomas of the breast are the most common type of breast cancer.

Adjuvant therapy: Additional treatment after surgical removal of the tumor. An example of adjuvant therapy is chemotherapy or hormonal treatment after surgery. It is used to prevent recurrence of tumor elsewhere in the body.

Adriamycin (doxirubicin): A drug used in chemotherapy for breast cancer. It is works by directly damaging DNA and stopping the growth of tumor cells. Side effects of this powerful drug are nausea and heart damage (cardiac toxicity).

Advanced breast cancer: This term describes Stage IV breast cancer (see staging of breast cancer), which means that the cancer has spread beyond the breast and adjacent lymph nodes to other organs of the body (lungs, bones, liver, brain, or distant lymph nodes and skin). Locally advanced breast cancers are tumors that, because of their size or their extension to skin overlying the breast, require chemotherapy and radiotherapy as their first treatment.

Aggressive cancer cells: These are fast growing cells that have a high capacity to spread beyond the area where they began growing.

Anti-emetic: A drug that prevents nausea related to chemotherapy.

Anti-estrogen: A drug that blocks the tumor-producing effects of estrogen. An example is tamoxifen.

Anti-HER-2 antibody therapy: Drugs that are used to treat breast cancer cells which contain abnormal number of the HER-2 gene and show many copies of the HER-2 protein receptor on their surface. Herceptin (trastuzumab) is an example of anti-HER-2 antibody therapy.

Areola: Area of dark-colored skin surrounding the nipple on the breast.

Arimidex (anastrozole): A drug that blocks the aromatase enzyme and thereby inhibits estrogen formation, which stimulates breast cancer growth. It is used to treat breast cancer in post-menopausal women. Called an aromatase-inhibitor or anti-estrogen drug.

Aromasin (exemestane): A drug like Arimidex that blocks aromatase.

Aromatase inhibitor: Drug used to treat breast cancer by reducing estrogen in the body. An aromatase inhibitor blocks the action of the enzyme, aromatase, which normally produces estrogen in fat cells. Using an aromatase inhibitor prevents estrogen synthesis. Examples of aromatase inhibitors are Aromasin (exemestane) and Arimdex (anastrozole) and Femara (letrozole).

Aspiration: Removal of a sample of fluid and cells using a needle and syringe.

Atypical hyperplasia: Hyperplasia is an area of increased growth of breast cancer glands. Atypical means that the gland cells are abnormal in appearance. Atypical hyperplasia is not breast cancer, but it is a finding on a pathology examination that may mean a higher risk for the later development of breast cancer.

Avastin (bevacizumab): A drug used to treat cancer by preventing the formation of new blood vessels (angiogenesis). The rationale for this drug is that if the tumor cells are deprived of blood supply, they will die.

Axilla: Armpit.

Axillary lymph nodes: Lymph nodes under the arms (arm pit). Lymph nodes are deposits of lymph cells along the pathway of lymph vessels. Lymph vessels carry a fluid known as lymph that contains white blood cells, water, protein and salts. When cancer cells multiply within a tumor, they can slip away from the tumor site and spread into lymph vessels. As they travel in the lymph vessels, tumor cells may become trapped in lymph nodes and begin new colonies of tumor growth. Since axillary lymph nodes are nearest to the breast, it is likely that the first spread of breast cancer cells would be to axillary lymph nodes. The sentinel lymph node is the first node to which a breast tumor travels. It is identified by injection of dye or radioactive substance (tracer) into the tumor bed and then monitoring the flow of the tracer to its first node.


Benign: Not cancerous. Benign tumors do not spread or invade adjacent tissues.

 Bilateral: Pertaining to two (both) sides.

Bilateral prophylactic mastectomy: Surgery to remove both breasts in order to prevent the development of breast cancer in an individual at high risk. It is also called a preventive mastectomy.

Biological therapy: Treatment to stimulate or restore the immune system to fight cancer, infections and other diseases. It can also be used to lessen side effects caused by cancer treatments. Examples of agents used in biological therapy are monoclonal antibodies, growth factors, and vaccines. The therapy is also known as biotherapy, biological response modifier (BRM) therapy, and immunotherapy. An example of a drug used in biological therapy is Avastin (bevacizumab).

Biopsy: A breast biopsy is a procedure to cut out small amount of tissue from an area of concern in the breast. The tissue sample is examined by a pathologist (a doctor who specializes in diagnosing disease) to see whether or not cancer cells are present. If cancer is present, the pathologist can then look at the cancer’s characteristics. The biopsy findings will be indicated in a pathology report. Different types of biopsies are: fine needle aspiration biopsy, core needle biopsy, incisional biopsy (removal of a piece of tumor), and excisional biopsy (removal of the entire mass or tumor).

Bone scan: In this procedure, a radioactive substance (tracer) is injected into a vein and travels through the bloodstream. The tracer substance localizes to areas of bone destruction due to tumor spread. A special camera takes pictures of the tracer in bones. Areas that absorb tracer appear as hot spots revealing areas of cancer metastasis (spread). A bone scan is performed to find areas of bone cancer or determine whether a cancer from the breast has spread (metastasized) to bones.

BRCA 1: A gene located on chromosome 17. It normally acts to block the growth of cells in the breast and ovary. If this gene is mutated (changed) or lost, it makes a person more susceptible to developing breast or ovarian cancer. Mutations, if inherited, can confer a high risk to children of a breast cancer patient and carriers of this mutation. BRCA stands for breast cancer.

BRCA 2: A gene on chromosome 13 that normally helps to block cell growth. If this gene is mutated (changed), it makes an individual more susceptible to developing breast cancer, ovarian cancer, or in men, prostate cancer. It is one of several types of gene responsible for inheritance of breast cancer. BRCA gets its name from breast cancer.

Breast-conserving (or breast-sparing) surgery: Surgery to remove breast cancer tissue, but not the entire breast. Examples of breast-conserving surgery are lumpectomy (lump is removed), quadrantectomy (removal of one quadrant or one fourth of the breast) and segmental mastectomy (removal of malignant tissue as well as normal tissue in a specific region of the breast).

Breast density: Measure of the compactness of tissue in the breast. Denser tissues, such as fibrous and glandular tissue show up as light areas on mammograms while less dense tissue, such as fat, appears darker on x-ray images. It is more difficult to detect breast cancer by x-ray (mammogram) in a dense breast.

Breast implants: These are sacs filled with silicone gel used for breast reconstruction.

Breast reconstruction: Surgery, after mastectomy, to fill in the gap in breast tissue left by removal of the breast tumor. It uses fatty tissue or artificial implants (plastic filled with silicone or salt solution).

Breast self-examination (BSE): Examination of breasts that a woman does on herself by systematic and careful touching or palpitation.


 Calcifications: Small deposits of calcium in breast tissue. They appear as small white spots or flecks on a mammogram. Calcifications are especially prevalent after menopause and are usually non-cancerous (benign). However, certain patterns of calcifications (tight clusters with irregular shapes) may indicate breast cancer. Macro-calcifications are large white dots or dashes, and are usually not associated with cancer, while micro-calcifications are fine, white specks and may indicate the presence of cancer.

Carcinoma: A malignant tumor that begins from tissue that lines the gastrointestinal tract, lungs, or glands or skin. This lining tissue is called epithelial tissue and can arise in the breast, colon, liver, lung, stomach, or glands in the body.

Carcinoma in situ: A small site of malignant tissue that is found in the place that it began and has not yet spread locally or distantly. In situ is a Latin term meaning “in place.” Its presence increases the risk of later developing invasive breast cancer.

cc (cubic centimeter): A unit of metric volume. One ounce equals 33 cc.

Chemotherapy: Treatment with drugs that work against cancer cells.

Clavicle: Collarbone

Clean margins: Microscopic examination of a biopsy specimen shows that the tissue surrounding the tumor is free of cancer cells.

Close margins: Cancer cells are found in or very close to the outer edge of the breast tissue removed during biopsy or surgery. There is a high risk of recurrence and a wider excision of tissue is indicated when the margins are close.

Clinical trial: A research study that tests new methods of screening, preventing, diagnosing, or treating disease such as breast cancer. Clinical trials are usually carried out in a medical facility and measure the effectiveness and safety of drugs in large groups of individuals with cancer.

Complementary and alternative medicine (CAM): These types of treatment are used in addition to or instead of standard treatments. Examples are dietary supplements. acupuncture, meditation, and massage therapy. They may injure the patient if used inappropriately or in the place of standard treatment.

Compression sleeves: Compression wrappings cover entire arm and are used to encourage lymph fluid to drain from the extremity toward the trunk of the body. The sleeve helps relieve arm swelling (lymphedema) that may result from breast surgery, and provides pressure going from the fingers toward the body.

Compression stockings: Tight, elastic stockings that treat lymphedema by squeezing legs and making it easier for fluid to drain up toward the trunk of the body.

Contrast media: Dyes that provide contrast between tumor and normal tissue. Contrast media are used to enhance CT scans and MR imaging.

Core needle biopsy: This biopsy technique uses a large hollow needle. The surgeon or radiologist uses the hollow needle to remove several cylinder-shaped samples of tissue from the suspicious area in the breast. In most cases, the needle is inserted about 3 to 6 times. Usually core needle biopsy does not leave a scar. Ultrasound or mammography imaging helps guide the needle to the suspicious area.

Computerized tomography (CT scan): Images of structures in the body created by a computer that receives data from multiple x-rays taken in a series of cross-sectional views of the head, lungs, or abdomen.

Cycle (of chemotherapy or radiation): The period of time, usually 21-28 days, during which a patient undergoes chemotherapy or radiation treatment and has a break before the next treatment. This allows cancer cells to be attacked at vulnerable times and allows the body’s normal cells time for recovery from damage and prepare for the next cycle. Often, chemotherapy consists of 6 cycles of treatment.

Cytoxan (cyclophosphamide): Cytoxan is a chemotherapeutic drug that is used to treat breast cancer. It directly attacks DNA and is often given with another drug, Adriamycin. This combination is called AC. Another chemotherapy combination used for breast cancer is Taxotere and Cytoxan (TC).

Cyst: An abnormal sac of fluid or semi-solid tissue.


Deep Vein Thrombosis (DVT): Blood clot in a vein. Also called thrombosis.

Desquamation: Shedding of the outermost membrane or layer of skin. The word comes from the Latin “desquamare” meaning “to scrape the scales off a fish.” Desquamation of skin in the chest wall may occur as a side effect of radiation therapy for breast cancer. In dry desquamation, the skin of the breast becomes scaly and itching (pruritus) occurs. In moist desquamation, the skin thins and begins to weep.

Diagnosis: Diagnosis is the final statement of the kind of medical illness affecting a patient after physical examination, x-ray studies, laboratory tests, and tumor biopsy. In oncology, it indicates the final type of tumor, such as breast cancer. The term means complete (dia-) knowledge (-gnosis).

Differentiation: Term describing specialization of cells. When cells are differentiated, they have matured into the normal tissue of the breast or other organ in the body. If cells are poorly differentiated, they appear as unspecialized and primitive.

Digital mammography: X-ray recording of the breast in which the x-ray film is replaced by detectors that digitize, or convert the x-rays into signals that produce images seen on a computer screen. For the patient,the process of obtaining the images is the same as for conventional film mammography. This techniques is particularly useful for imaging premenopausal women with dense breast tissue. It is also known as full-field digital mammography (FFDM).

Dose (drug or radiation): A dose is the quantity of drug or radiation given to the patient.

Drain (Jackson Pratt or JP): A Jackson-Pratt (JP) is a type of drain that is placed in an incision during surgery to prevent fluid accumulation.

Drainage: Drainage is the fluid that leaks from a wound. Drainage contains components of blood. Four types of drainage are: serous (clear, watery fluid called serum), sanguineous (containing red blood cells and a thick, red appearance), serosanguineous (semi-thick reddish fluid containing both serum and blood), and purulent (fluid containing pus resulting from an infection). Serous drainageis also called clear or lymphatic.

Duct: Tube in the breast in which milk flows to the nipple for breast feeding.

Ductal carcinoma in situ (DCIS): This type of breast cancer stays inside the milk ducts and doesn’t invade surround tissue. The term, in situ, is Latin for “in place.”


Electron boost: An additional treatment of low energy x-rays to kill tumor cells in the skin or overlying a tumor.

ER-negative: Used to describe breast cancer tumor cells that do not have estrogen receptors on their cell surfaces, so will not be affected by therapy that targets estrogen.

ER-positive: Used to describe breast cancer tumor cells that have estrogen receptors (which help growth of the tumor) on their cell surfaces. The growth of the tumor cells will be stopped by drugs that block estrogen and its receptors. Two-thirds of breast cancer tumors have ER receptors.

Erythema: Redness of the skin.

Estradiol: A natural form of estrogen.

Estrogen: A hormone produced by the ovaries and (in smaller amounts) by the adrenal glands and fatty tissue. It is responsible for female sex characteristics and is thought to encourage the growth of breast cancer cells in estrogen receptor positive breast cancers.

Excisional biopsy: A type of biopsy in which a surgeon removes an entire area (lump) of suspicious tissue from the breast. A small rim of normal tissue around the suspicious area will be removed as well. This area of normal tissue is known as a margin. Ultrasound or mammography guidance and needle wires inserted in the breast are used to find the correct location for biopsy. As with an incisional biopsy, local anesthetic and medication for light sedation are necessary.

Exemestane (aromasin): An aromatase inhibitor that lowers estrogen levels in post-menopausal women.

External radiation: Radiation therapy delivered by a machine that aims high energy rays (photons or protons) at cancer cells. Also called external-beam radiation.


Femara (letrozole): An aromatase inhibitor that lowers estrogen levels in post-menopausal women.

Fertile: Able to become pregnant.

Fibroadenoma: A benign tumor of the breast, found on x-ray imaging (mammography).

Fibrocystic disease: A non-cancerous condition in which breast tissue feels abnormally firm and consists of areas of dense tissue surrounded by dilated glands and ducts.

Fine needle aspiration biopsy (FNA): In this biopsy, the surgeon or radiologist uses a thin needle with a hollow center to withdraw a sample of cells from a suspicious area in the breast. Imaging studies may be necessary to guide the needle to the correct location. In an ultrasound-guided biopsy, the doctor watches the needle on an ultrasound monitor to guide it to the proper area. In stereotactic needle biopsy, mammography is used to guide the needle. Mammograms are taken from different angles to pinpoint the location of the breast mass (tumor).

FISH (Fluorescence In Situ Hybridization) test: This test is done on breast cancer tissue removed during biopsy to determine whether the cells have extra copies of the HER2 gene. The more copies of the HER2 gene that are present, the more HER2 receptors the cells have. The HER2 receptors receive signals that stimulate the growth of breast cancer cells. FISH test results indicate that the cancer is either “positive” or “negative” (a result sometimes reported as “zero”) for HER2. Generally, the FISH test is not as widely available as another method of testing for HER2, the ImmunoHistoChemistry, or IHC. However, FISH is considered more accurate. In many cases, a testing facility will perform the IHC test first, ordering FISH only if the IHC results don’t clearly show whether the cells are HER2-positive or negative.

Frozen section: Tissue removed by biopsy and then frozen and thinly sliced to allow microscopic examination during an operative procedure that guides the decision to use adjuvant (further post-surgical) therapy.


 Gene array: A test of tumor tissue for the presence of active genes. Certain gene array patterns indicate the risk of later recurrence of tumor and the need for adjuvant (further) therapy.

Genetic testing: Testing (via blood sample) to indicate the presence of an inherited cancer causing genes, such as BRCA 1 or 2.

Grading cancer cells: Grading is the determination of how different cancer cells are from normal cells. Pathologists compare the appearance of cancer cells to normal breast cells. They assign a grade to the cancer cells. For example, Grade 1 (low grade or well differentiated) cancer cells do not look very different from normal cells and are usually slow growing. Grade 2 (moderate or intermediate grade) indicates that the cancer cells are more likely to invade and metastasize (move outside the breast). Grade 3 (high grade or poorly differentiated) cancer cells are clearly very different from normal cells, are fast-growing and have a high potential for metastasis.

Growth factors: A general category of protein factors that stimulate the growth of normal bone marrow, tissues, and at times, malignant cells.

Gynecology: Study of diseases affecting women and the female reproductive organs.


Hematocrit: Percentage of red blood cells in a volume of blood. A low hematocrit indicates anemia (decrease in numbers of red blood cells or the hemoglobin within the red blood cell).

HER2: A receptor protein on the surface of breast cancer cells that binds to a growth factor and stimulates cell growth. Also called HER2/neu. HER stands for human epidermal growth factor receptor. It is coded or regulated by the Her2 gene. On biopsy, breast cancer cells are tested for the presence of HER-2 receptor protein on their surface. If the cells are HER-2 negative it means that HER-2 is not present or present in very small amounts, and that breast cancer cells will not respond to a type of drug treatment (herceptin or trastuzumab) that blocks the action of the HER-2 receptor. If breast cancer cells are HER2 positive on biopsy testing, it means that HER2 (protein on the surface of breast cancer cells) is strongly present, and that if patients are treated with a drug (herceptin or trastuzumab) that blocks the function of the HER2 receptor, breast cancer cells will stop growing and may die.

Herceptin (trastuzumab): A drug (monoclonal antibody) that interferes with the HER2 receptor. Its main use is to treat breast cancers that are HER2-positive.

Hormone therapy: Treatment that blocks the hormonal path (estrogen and its receptor) that stimulates tumor growth.

Hyperplasia: Increase in number of cells.

Hormone replacement therapy: Use of estrogen, with or without progesterone, to counteract the unpleasant side effects of menopause.


IHC (immunoHistoChemistry) test: This test uses a colored antibody that attaches to a target protein of interest. It is a test that determines the presence of HER2 receptor on breast cancer cells. It is a special staining process performed on fresh or frozen breast cancer tissue removed during biopsy. IHC is a commonly used test to determine if a tumor has HER2 receptor protein on its surface. The IHC test gives a score of 0 to 3+ indicating the amount of HER2 receptor protein on the cells. If the tissue score is 0 to 1+, it is HER2 negative. If the score is 3+, it is HER2 positive. If the result is 2, it is borderline and will be retested using FISH.

Implant: A plastic sac containing salt solution (saline) or silicon, used to reshape the breast after mastectomy.

Implant extrusion: Escape of saline or silicon from an implant.

IMRT (intensity modulated radiation therapy): A finely shaped beam of x-rays used to deliver precise x-ray treatment to the breast.

Inflammatory breast cancer: A rare type of breast cancer in which there is no single lump or tumor. The skin of the breast, however, looks red and may feel warm. The breast becomes larger, with a thick, pitted appearance. These skin changes are caused by cancer cells that block lymph vessels in the skin. Inflammatory breast cancer may be mistaken for inflammation of the breast (mastitis), but a biopsy reveals the correct diagnosis. This type of breast cancer has a higher chance of spreading than the more common solitary lump within the breast.

Incisional biopsy: Type of biopsy during which a surgeon uses a local anesthetic or numbing drug and removes a small piece of the tumor tissue to be examined by a pathologist. Additionally, the surgeon may use a procedure called needle wire localization in which a small hollow needle is inserted into the abnormal area. A small wire is placed through the needle into the area. After the needle is removed, the doctor uses the wire as a guide in finding the exact spot for biopsy sample. Ultrasound or mammography guides the surgeon in the procedure.Incisional biopsy is more invasive than needle biopsy. It may leave a small scar and may take longer time to recover.

Invasive (infiltrating) ductal carcinoma: A type of breast cancer that starts in breast gland ducts and spreads into the surrounding normal tissue. It is the most common type of breast cancer. Tumor cells break through the mammary ducts and grow into the fatty and connective (supporting) tissue of the breast.

Invasive (infiltrating) lobular carcinoma: A type of breast cancer that starts in milk producing lobules, and spreads into the surrounding normal tissue. It is a less common type of breast cancer. About 1 in 10 invasive breast cancers is a lobular carcinoma, while 9 in 10 are of ductal origin.


Jackson-Pratt drain: A Jackson-Pratt (JP) is a type of drain that is placed in an incision during surgery to prevent fluid accumulation.


Letrozole (Femara): An aromatase inhibitor that lowers estrogen levels in post-menopausal women.

Lobular carcinoma in situ (LCIS): An overgrowth of cells within a lobule in the breast. It does not invade surrounding normal tissue. Women with this condition have a higher risk of developing invasive breast cancer and should have regular mammograms.

Localized cancer: Cancer that has not spread beyond the breast tissue.

Lump: Mass of tissue or swelling of tissue.

Lumpectomy: Removal of a lump from the breast.

Lymph : Transparent, usually slightly yellow, liquid found within the lymphatic vessels, and collected from tissues in all parts of the body and returned to the blood via vessels in the upper chest. It is chiefly composed of white blood cells called lymphocytes.

Lymphedema: An abnormal swelling that occurs when there is a blockage in the lymphatic system, which then cannot adequately drain the circulating lymph fluid. This swelling can result from lymph node removal during breast cancer surgery; damage from radiation therapy, or blockage, injury or infection in the axillary lymph node area. The swollen arm is at greater risk for serious infections, even from minor injuries to the hand or arm.

Lymph nodes: Stationary islands of lymph cells along the pathway of lymph vessels. Lymph vessels carry a fluid (lymph) that contains white blood cells, water, protein and salts. When cancer cells multiple rapidly within a tumor, cells can slip away from the tumor site and spread into lymph vessels. As they travel in the lymph vessels they may become trapped in lymph nodes and start new colonies of tumor growth in those nodes. There is a increased risk of cancer returning when cancer cells are found in lymph nodes. If cancer cells are found in lymph nodes or lymphatic vessels, the pathology report will say lymphatic invasion is present and there are “positive” lymph nodes. If there is no invasion, the pathology report will say absent and lymph nodes are “negative” for cancer.

Lymph node dissection: Removal of lymph nodes.


Malignant: Cancerous. Malignant tumors invade nearby tissue and may spread to more distant parts of the body.

Mammary: Related to the breast.

Mammography: X-ray images of the breast, used to screen for both cancers and abnormal pre-cancerous conditions. An abnormal screening mammogram may require a biopsy of the suspicious lesion.

Mammotome: See Vacuum assisted biopsy.

Margin: A margin is the distance from the tumor to the edge of the normal surrounding tissue that is removed with it. If the margin of normal tissue is very narrow, it will be necessary to repeat the surgery to take a wider margin. A pathologist checks the tissue under a microscope to see if the margins are free of cancer cells.

Mastectomy: Removal of the breast. Types include radical, modified radical, skin sparing, nipple sparing, prophylactic.

Mastitis: Inflammation of the breast, usually due to infection. Mastitis causes swelling, erythema (redness) and pain.

Mediastinal: The mediastinum is the space in the chest between the lungs and below the breastbone (sternum). There are many lymph nodes in the mediastinum, and they may harbor metastatic tumor from breast cancers.

Medical oncologist: A physician specializing in the diagnosis and treatment of malignant tumors.

Metastasis: The spread of a cancerous tumor to a site beyond the breast. Meta- means beyond, -stasis means to stop or control.

Microcalicifications: Small deposits of calcium in breast tissue. Certain patterns of calcifications (tight clusters with irregular shapes) may indicate breast cancer. Micro-calcifications are fine, white specks and may indicate the presence of cancer.

Mixed tumors: These tumors contain a variety of cell types, such as ductal tumor cells and cells resembling connective tissue (sarcoma cells), and are treated as if they were invasive ductal breast cancer.

MRI (Magnetic Resonance Imaging) : A very precise image or picture created by placing the body in a strong magnetic field that detects the rotation of water molecules as they align in the field and then relax as the field is turned off. MRI does not use radiation particles.

MRI guided biopsy: A biopsy is performed under guidance of MR imaging.

Mucinous carcinoma: A rare form of invasive ductal carcinoma. It accounts for about 2-3{80a5668e922b9fd980dde0a6d6f2a27c110d8d696a90e3ef35289df5d75c2aa7} of all breast cancer. Tumors are formed from abnormal cells that give off mucin, a sticky substance found in the body lining inner surfaces such as the digestive tract and lungs. Also called colloid carcinoma.

Multidisciplinary clinic: A patient is seen at the clinic by a medical oncologist, radiation oncologist, and surgeon and they all confer on the treatment plan.

Mutation: A defect in DNA that causes a change in the proteins of a cell and may lead to cancer.


Neo-adjuvant: Chemotherapy or radiation performed to shrink tumor before surgery.

Nipple discharge: Bloody secretion from the nipple which may indicate the presence of underlying cancer.

Non-invasive cancer: Cancer which stays in a localized area and does not invade surrounding tissue.

Nonpalpable cancer: A type of tumor that cannot be felt.


Oncologist: Medical doctor specializing in diagnosis and treatment of cancer.


Paget disease of the nipple: Redness and discharge of fluid from the breast nipple; indicates underlying breast cancer.

Palpation: Examination by touching or feeling a part of the body.

Pathologist: A medical doctor who specializes in examining biopsy samples under a microscope to determine the correct diagnosis.

Pathology: The study of abnormal tissue associated with disease. Clinical pathology is the diagnosis of disease based on the laboratory analysis of bodily fluids such as blood, urine, and tissues using the tools of chemistry, microbiology, hematology, and molecular pathology.

Peau d’orange: Skin change that resembles orange peel.

PET scan (positron emission tomography): This diagnostic test detects the rapid uptake of a radioactive glucose (sugar) by tumor cells. It is used to confirm the presence of a suspicious and possibly malignant tumor.

Phlebotomy: Puncture of a vein to remove blood. This procedure is used to obtain blood samples for testing.

Platelets: Clotting cells (thrombocytes) found in the blood.

Port: The site on the body to which radiotherapy is administered.

Portacath (port): An implanted tube that connects to a vein. It is implanted under the skin to give permanent access to a vein for administration of drugs. From port- (portal or entrance) and cath- (catheter or tube).

Port films: X-rays taken to help set up or design location and shape of irradiation to be given to breast cancer.

Precancerous: Abnormal growth that can become a cancer. In the breast, a precancerous lesion is DCIS (ductal carcinoma in situ).

Preventive mastectomy: See prophylactic mastectomy.

Progesterone: A hormone that stimulates breast cancer growth.

Prognosis: A prediction about the outcome of treatment. The prognosis is the estimation of the chances for cure versus tumor recurrence.

Prophylactic mastectomy (preventive mastectomy): Surgery to remove a breast to reduce the risk of developing breast cancer. Often performed in patients who carry the BRCA 1 or BRCA 2 genes. Prophylactic means pertaining to prevention.

Prosthesis: Breast implant to create normal breast shape after surgery.

Purulent: Pertaining to being filled with pus; see Drainage.


Quadrantectomy: Surgery to remove one quarter of the breast. It is a breast conserving procedure and a partial mastectomy.


Radiation oncologist: A medical specialist who uses high-energy rays (photons or protons) to treat and destroy cancer cells.

Radiation therapy: Treatment of cancer using high-energy rays (photons or protons) to kill cancer cells.

Radiologist: A medical specialist who diagnoses disease (such as breast cancer) by using x-ray techniques, ultrasound, and MRI.

Raloxifene: A drug that blocks the estrogen pathway. It is an oral selective estrogen receptor modulator (SERM) that has estrogenic actions on bone, but blocks estrogen action on breast cancers. Also called Evista.

RBC (red blood cell): Blood cell that carries oxygen. Medical term is erythrocyte.

Reconstruction:  Surgery done by a plastic surgeon to rebuilds the breast mound after mastectomy. FLAP reconstruction procedures take tissue from one area of the body (such as the lower abdomen, buttock, or upper thigh) and moves it to the chest area to reconstruct the breast that has been removed or damaged. Types of reconstruction include TRAM flap, DIEP, GAP, Stacked or TUG.

Recurrence (relapse): Disease returns after initial therapy.

Remission: Disease disappears with treatment. All imaging studies return to normal.

Resection: Removal.


Sanguineous: Pertaining to bloody drainage from a wound; see Drainage.

Sentinel node biopsy: See lymph nodes.

Seroma: Collection of clear fluid.

Serosanguinous: Drainage from a wound, containing serum and blood; see Drainage.

Serous: A type of drainage from a wound; see Drainage.

Side effects: Undesirable symptoms, such as nausea, vomiting or damage to normal tissue, such as depression of blood counts, caused by drugs or radiation therapy, or surgery.

Silicone breast implants: Sacs with a silicone outer shell filled with silicone gel. They come in different sizes and have either smooth or textured shells. Differences in the type of silicone and the type of outer shell determine the ultimate shape and feel of the implants, whose types include cohesive gel, capsular, contracture, and rupture.  The three companies with FDA-approved silicone implants are Mentor, Alergan and Sientra.  (cohesive gel, capsular, contracture, rupture)

Staging of breast cancer: Defining the extent of spread of a cancer. Stage I = up to 2 cm tumor and negative nodes. Stage II= 2-5 cm tumor and positive nodes. Stage III = >5 cm tumor and may have spread to axillary lymph nodes or chest wall. Stage IV =tumor has spread to distant sites.

Stage IV (often called advanced or metastatic)is invasive cancer that has spread beyond the breast and nearby lymph nodes to other organs, such as liver, lungs, bones, brain, and distant lymph nodes or skin.

Stereotactic needle biopsy: In this fine needle biopsy technique, mammography is used to view the suspicious mass from different angles so that correct placement of the biopsy needle is achieved.

Sternum: Breastbone.


Tamoxifen: A drug that blocks the estrogen receptor on breast cancer cells. Tamoxifen or an aromatase inhibitor is the usual endocrine (anti-estrogen) therapy for breast cancer that is positive for the estrogen receptor.

Taxol (Abraxane, paclitaxel) and Taxotere (docetaxel): These drugs are derived from the taxus (yew) tree. They are highly effective for treating breast cancer.

Tomosynthesis (mammography): Digital x-ray imaging technique that produces a 3D view of breast tissue to improve breast cancer screening and detection.

Thrombosis (Also called deep vein thrombosis): Blood clot in a vein.

Treatment planning (radiation): The process of specifying the areas of the body to receive x-ray therapy. It is done with careful attention to x-rays and identifying the precise location of the tumor.

Triple negative breast cancer: When cancer cells are biopsied, they are also tested for the presence of receptors on their cell surface. Certain invasive ductal carcinomas lack three particular receptors and are called triple negative cancers. The three receptors are estrogen, progesterone, and HER2 receptors. Without these receptors, the tumor cells do not respond to drugs that block estrogen, progesterone, or the HER2 protein and have a higher chance of spreading outside the breast.

Tumor size: The size (diameter) of tumors is measured in centimeters (cm). A centimeter is a little longer than a third of an inch. A tumor of three centimeters is a little more than an inch across. A tumor measuring 5 centimeters is about 2 inches across. Size is only one characteristic of a tumor. The grade and presence of hormone and HER-2 receptors are important as well in determining the need for certain treatments after removal of the tumor.


Ultrasonography: Use of ultrasound waves to create images of the body.

Ultrasound guided biopsy: Ultrasound images are used to guide the physician in selecting the proper location to remove samples of a tumor mass.

Unilateral: Pertaining to one side.


Vacuum Assisted Biopsy (VAB): A biopsy of breast tissue done using imaging guidance through a small incision in the skin with a special needle that takes tissue samples using a vacuum-powered instrument. This type of biopsy is done when breast imaging shows up abnormalities too small to be felt and potentially difficult to remove using needle biopsy.


WBCs (white blood cells): Cells in the blood that fight infection.


Xeloda (capecitabine): Chemotherapy with a fluorouracil derivative for advanced breast cancer.

X-rays: Images made by shooting electrically charged particles through the body. The particles are absorbed by dense tissues such as bone, tumor, or muscle, and these structures create shadows on the photographic detector plate positioned behind the body part.


About the Author

Davi-Ellen Chabner, BA, MAT, is an author and lecturer based in the Boston area. Her best-selling medical textbook The Language of Medicine, is currently in its Tenth Edition.


© 2013 Davi-Ellen Chabner. All rights reserved. May not be 
republished without the author's consent.