American College Of Surgeons - Inspiring Quality: Highest Standards, Better Outcomes

Breast Cancer Glossary of Medical Terms

Developed by the National Accreditation Program of Breast Centers (NAPBC)


Abscess – A closed pocket of tissue containing pus, most commonly caused by a bacterial infection.

Accessory breast tissue – An uncommon condition in which additional breast tissue is found in the axillary (underarm) area. Women with this condition often require special mammographic examination.

Adenocarcinoma – Cancer that originates in the glandular tissue, such as in the ducts or lobules of the breast.

Adenoma – A benign growth originating in the glandular tissue of the breast that can compress adjacent tissue as it grows in size. (See also fibroadenoma.)

Adjuvant therapy – Treatment provided in early breast cancer in addition to the primary surgery in an effort to increase its effectiveness, i.e., surgery and chemotherapy. Adjuvant chemotherapy or hormonal therapy is given in hopes of preventing a recurrence of the cancer.

Advanced cancer – A stage of cancer in which the disease has spread from the primary site to other parts of the body. When cancer has spread only to the surrounding area, it is called regional. If it has spread further by traveling through the bloodstream or lymphatic system, it is called distantly advanced, metastatic, or Stage IV cancer.

Alopecia – Hair loss that may include scalp, pubic, eyebrows, and other hair producing areas. Temporary alopecia often occurs as a result of chemotherapy or less commonly, when radiation therapy is administered to the head. Hair does regrow after chemotherapy, but hair loss may be permanent following certain radiation treatments.

Anemia – A condition that occurs when there is not enough hemoglobin in a person’s blood. Hemoglobin is a substance in the red blood cells that enables the blood to transport oxygen through the body.

Anesthesia – The loss of feeling or sensation as a result of drugs or gases. General anesthesia causes loss of consciousness (‘put you to sleep’). Local or regional anesthesia causes loss of feeling or sensation to a specified area.

Aneuploid – An abnormal number of chromosomes; a characteristic of cancer. (See also ploidy.)

Antibiotic – Chemical substances produced by living organisms or synthesized (created) in laboratories, for the purpose of killing other organisms that cause disease. Some cancer therapies interfere with the body’s ability to fight off infection as they suppress the immune system, so antibiotics may be needed along with the cancer treatment to prevent or treat infections.

Antibody – An immune system protein in the blood that defends against invading foreign agents, such as bacteria. Invading agents contain certain chemical substances called antigens. Each antibody works against a specific antigen. (See also antigen.)

Antiemetic – A drug used to control nausea and vomiting (emesis), which are common side effects of chemotherapy. Antiemetic drugs can be used before, during, and after chemotherapy, and may be given either intravenously or as pills.

Antiestrogen – A substance that blocks the effects of the hormone estrogen on tumors (for example, the drug tamoxifen). Antiestrogens are used to treat breast cancers that depend on estrogen for growth (estrogen-receptor-positive cancers).

Antigen – A chemical substance that stimulates an immune system response. Cancer cells have certain antigens that can be detected by laboratory tests, and are important to cancer diagnosis and in monitoring response to treatment.

Areola – The area of dark-colored skin that surrounds the nipple.

Aromotase inhibitor – A class of drugs that decreases the production of estrogen and is used as hormonal therapy in breast cancer that is estrogen-receptor positive (estrogen-receptor-positive cancers).

Aspiration – Removal of tissue or fluid from a lump or a cyst.

Asymmetry – Not proportional or the same. It is normal for women to have slightly asymmetrical breasts.

Asymptomatic – To be without noticeable symptoms of disease. Many cancers can develop and grow without producing symptoms, especially in the early stages.

Atypical – Literally “not typical.” Abnormal, but not cancer.

Atypical hyperplasia – A benign (non-cancerous) condition in which breast tissue has certain abnormal characteristics. This condition increases the risk of breast cancer.

Augmentation mammoplasty – Surgery to increase the size of the breast(s).

Autologous – Using one’s own tissue. An autologous reconstruction uses the patient’s own tissue to reconstruct the breast.

Axilla – The underarm, the armpit.

Axillary node dissection – A surgical procedure in which the lymph nodes in the armpit (axillary nodes) are removed and examined by a pathologist to find out if breast cancer has spread to those nodes and to remove cancerous lymph nodes.


Benign – Not cancerous, not malignant. The most prevalent types of breast problems are fibroadenoma and fibrocystic disease. See also fibroadenoma, fibrocystic change.)

Bilateral – Affecting both sides of the body, i.e., bilateral breast cancer is cancer occurring in both breasts at the same time or at different times.

Biopsy – A procedure in which tissue samples are removed from the body for examination of their appearance under a microscope to find out whether cancer or other abnormal cells are present. A biopsy can be done with a needle or by surgery.

  • Excisional breast biopsy - The surgical removal of the entire suspicious breast mass (tissue mass or mammographic abnormality) and surrounding margin of normal tissue.
  • Incisional breast biopsy - The removal of part of a lump for microscopic (pathologic) examination.
  • Core needle biopsy - Removal of tissue or fluid from a lump or cyst with a large needle.
  • Fine needle aspiration - Removal of tissue or fluid from a lump or a cyst with a thin needle and a syringe.
  • Stereotactic core needle biopsy - A method of needle biopsy that is useful when calcifications or a mass can be seen on mammography but cannot be located by touch or breast ultrasound. Computerized equipment maps the location of the mass and this map is used as a guide for the placement of the needle.
  • Ultrasound-guided needle biopsy – An ultrasound directed needle biopsy is a technique used when calcifications or a mass can be seen on ultrasound but cannot be located by touch.

Blood count – The number of red bloods cells, white blood cells, and platelets in a sample of blood. Also called a complete blood count (CBC).

Bone densitometry – An examination used to measure a patient’s bone mineral density in various parts of the body, such as the spine, hip, heel, or wrist. This examination is useful in determining whether a patient has osteoporosis.

Bone scan – A nuclear imaging method that gives important information about the bones, including the location of cancer that may have spread to the bones. This examination can be done as an outpatient procedure and is usually painless, except for the needle stick when a low-dose radioactive substance is injected into a vein. Images are taken to see where the radioactivity accumulates, indicating an abnormality.

Brain scan – A nuclear medicine imaging method used to find abnormalities in the brain, including brain cancer and cancer that has spread to the brain from other places in the body. This examination can be done as an outpatient procedure and is usually painless, except for the needle stick when a low-dose radioactive substance is injected into a vein. Images are taken to see where the radioactivity accumulates, indicating an abnormality.

BRCA1 – Breast Cancer Gene 1 – A gene which, when damaged (mutated), places a woman at greater risk of developing breast cancer and/or ovarian cancer, compared with women who do not have this mutation. A genetic test is available. Any women considering the test should consult with a genetic counselor for further discussion.

BRCA2 – Breast Cancer Gene 2 – A gene which, when damaged (mutated), places a woman at greater risk of developing breast cancer and/or ovarian cancer, compared with women who do not have this mutation. A genetic test is available. Any women considering the test should consult with a genetic counselor for further discussion.

Breast augmentation surgery – Surgery to increase the size of the breast(s).

Breast biopsy – The removal of breast tissue for pathologic examination. A breast biopsy is performed to determine whether a suspicious area of the breast is cancerous or benign.

Breast cancer – Cancer that originates in the breast.

Breast compression – The flattening of the breast so that the maximum amount of tissue can be imaged and examined during mammography.

Breast conservation therapy – Also called lumpectomy or partial mastectomy; the surgical removal of a cancerous breast mass, whether palpable or non-palpable, and a small amount of non-cancerous tissue around the lump, without removing any other part of the breast.

Breast density – Describes breast tissue that has many glands close together. Dense breasts may make masses difficult to detect by physical examination or mammography.

Breast expander – A device used to stretch the remaining breast skin after a mastectomy. A breast expander is similar to a balloon, and the surgeon will fill the expander with salt-water solution periodically (usually once a week). The expansion process typically takes three to four months. After the skin is sufficiently stretched, the surgeon will replace the expander with a permanent breast implant. (See also tissue expander.)

Breast pain – Cyclic or non-cyclic pain in the breast or in the axilla (underarm) region of the body. Breast pain is not usually associated with breast cancer.

Breast prosthesis – An external breast form shaped like a breast, which resembles the body’s own weight and touch. Some women wear prostheses after mastectomy (breast removal).

Breast reconstruction – Surgery that rebuilds the breast contour after mastectomy. Reconstruction can be done at the time of mastectomy (immediate reconstruction or one-stage) or at a later date (delayed reconstruction or two-stage).

  • Breast implant reconstruction – a method of breast construction that utilizes an implant to reconstruct the breast. The most common implant is a saline-filled implant. It is a silicone shell filled with salt water (sterile saline). Silicone gel-filled implants are another option for breast reconstruction.
  • DIEP (deep inferior epigastric artery perforator) flap – The DIEP flap uses fat and skin from the abdominal area, but does not use the muscle to form the breast mound as the TRAM flap reconstruction. This method uses a free flap, meaning that the tissue is completely cut free from the abdominal wall and moved to the chest area. This requires the use of a microscope (microsurgery) to connect the tiny vessels.
  • Gluteal free flap – the gluteal free flap reconstruction uses tissue from the buttocks, including the gluteal muscle, to create the breast shape. The skin, fat, blood vessels, and muscle are cut out of the buttocks and then moved to the chest area. A microscope (microsurgery) is needed to connect the tiny vessels.
  • Latissimus dorsi flap procedure – A method of breast reconstruction that uses the long flat muscle of the back by rotating it to the chest area.
  • Nipple-sparing procedures – a reconstructive procedure that preserves the nipple and areola while the breast tissue under them is removed.
  • Transverse rectus abdominus muscle flap procedure – a method of breast reconstruction in which tissue from the lower abdominal wall which receives its blood supply for the rectus abdominus muscle is used. The tissue of this area is moved up to the chest to create a breast mound and usually does not require an implant. Moving muscle and tissue from the lower abdomen to the chest results in flattening of the lower abdomen (a “tummy tuck”). Also called a TRAM flap or rectus abdominus flap procedure.
  • Tissue flap reconstruction – These procedures use tissue from the abdomen, back, thighs, or buttocks to rebuild the breast. The two most common types of tissue flap surgery are the TRAM flap, which uses tissue from the abdominal area, and the latissimus dorsi flap, which uses tissue from the upper back.

Breast reduction surgery – Surgery to reduce the size of the breast(s). (See also reduction mammoplasty.)

Breast self-examination (BSE) – A technique of checking one’s own breasts for lumps or suspicious changes.

Breast specialist – A term describing healthcare professionals who have a dedicated interest in breast health. While they may acquire specialized knowledge in this area, medical licensing boards do not certify a specialty in breast care.

Breast surgeon – A physician with a medical doctorate (MD) degree and advanced training in surgical techniques. Some surgeons specialize in specific areas in the body (for example, the breast). Breast surgeons perform breast biopsy, lumpectomy, mastectomy, sentinel node biopsy and axillary node dissection on patients diagnosed with breast cancer. 

Adapted or Reproduced for Educational Purposes from:

Breast reconstruction after mastectomy. American Cancer Society website. Internet (
Reconstruction_After _Mastectomy_5.asp
,) retrieved June 10, 2010.

Breast reconstruction. American Society of Plastic Surgeons website. Internet (
Reconstructive_Procedures/ Breast_Reconstruction.html
,) retrieved June 10, 2010.

Cancer facts, National Cancer Institute, (2005)

Breast Cancer Glossary. Cleveland Clinic website. Internet (
,) retrieved May 17, 2010.

Breast cancer glossary of medical terms. Imaginis website. Internet (,) retrieved May 17, 2010. 

Reviewed and approved by the NABPC Access and Utilization Committee, July 2010.