False negative: Term used to describe an incorrect test result of a medical procedure or test that falsely shows the lack of a finding.  For example, a mammogram may not show any breast abnormality, yet breast cancer is present.  The mammogram result is a false negative.  A false negative result can occur for a variety of reasons, including operator error or limitations of the test. 

False positive: Term used to describe a test result that wrongly or inaccurately shows the presence of a disease or other conditions when none exist.

Fascia: A sheet or thin band of fibrous tissue that covers muscles and various organs of the body.

Fat necrosis: The death of fat cells, usually following injury. Fat necrosis is a benign (non-cancerous) condition, but it can cause a breast lump, pulling of the skin, or skin changes that can be confused with breast cancer.

Fenretinide: A non-toxic drug related to Vitamin A.  Researchers are investigating whether fenretinide may reduce the risk of breast cancer recurrence in pre-menopausal women.

Fibroadenoma: A type of benign (non-cancerous) breast tumor composed of fibrous tissue and glandular tissue. On clinical examination or breast self-examination, it usually feels like a firm, round, smooth lump. These usually occur in young women.

Fibrocystic change: A term that describes certain benign (non-cancerous) changes in the breast; also called fibrocystic disease. Symptoms of this condition include cysts (accumulated packets of fluid), fibrosis (formation of scar-like connective tissue), lumpiness, areas of thickening, tenderness, or breast pain. Because these signs sometimes mimic breast cancer, diagnostic mammography or microscopic examination of breast tissue may be needed to show that there is no cancer.

Fibrosis: Formation of fibrous (scar-like) tissue. This can occur anywhere in the body.

Filgrastim: A drug used to treat neutropenic patients (those with a decreased white blood cell count).  Brand name, Neupogen.

Fine needle aspiration: Removal of tissue or fluid from a lump or a cyst with a thin needle and a syringe. (See also needle aspiration).

Flap: Term used to describe the transfer of skin and soft tissue from one part of the body to help reconstruct another part. In most instances the flap is attached to the body by its blood supply. The place where the flap is taken from (harvested) is called the donor site. The place on the body where the flap is transferred to is called the recipient site (for example, the breast).

Flap donor sites: The location on the body that a flap of tissue is taken from for breast reconstruction.   For example, in a TRAM flap procedure, tissue is taken from the abdomen and transferred to the breast (the recipient site) to reconstruct the breast after a mastectomy.

Follow-up care: After primary breast cancer treatment, patients are usually monitored with mammograms and other tests. 

Flow cytometry: A test of tumor tissue to see how fast the tumor cells are reproducing and whether the tumor cells contain a normal or abnormal amount of DNA. This test is used to help predict how aggressive a cancer is likely to be. (See also ploidy, DNA, S-phase fraction).

“Free” flap: Term used to describe a breast reconstructive procedure that is completely detached from its donor site and transferred to the recipient site by reattaching the blood vessels of the flap (tissue) to vessels of the recipient site.  For example, in a TRAM flap procedure, tissue is taken from the abdomen (donor site) and transferred to the breast (recipient site) to reconstruct the breast after a mastectomy.  Also called microvascular flap.

Frozen section: Microscopic examination of a specimen of tissue that has been quick-frozen. This method gives a quick diagnosis, sometimes while the surgeon is waiting to complete a procedure. The diagnosis is confirmed in a few days by a more detailed study called a permanent section. (See also permanent section).

Updated: August 2006