- Pertaining to a growth or an abnormal patch of tissue that is not yet cancerous but is poised to become cancerous. "Pre-" means "before" and "-malignant" means "cancerous." Thus, premalignant tissue is precancerous tissue. Premalignant tissue may develop on the skin or inside the body. Appropriate clinical and laboratory studies are designed to detect premalignant tissue while it is still in a premalignant stages. A large battery of techniques are available to remove or kill the tissue, thereby preventing the development of cancer. Following are a few examples of premalignant growths: Colon Growth: Polyp A premalignant growth called a polyp occurs in the colon in two forms. One form has a stem with an umbrella-like top. This type of polyp resembles a mushroom. The second form has no stalk, only the umbrella top. Although the causes of most polyps are not yet fully fathomed, it is known that an inherited disease called familial adenomatous polyposis (FAP) can lead to the development of hundreds of colon polyps in a person with FAP. Skin Growth: Actinic Keratosis Premalignant tissue on the skin occurs as a scaly patch slightly elevated above the surface. The patch, usually red or brown, is rough and horny. Prolonged and frequent exposure to sunlight is the primary cause of this type of premalignant condition. The technical term for such a patch is actinic keratosis. ("Actinic" refers to sunlight or radiation; for example, an actinic burn would be caused by exposure to the sun's rays or to X-rays, not by exposure to fire. "Keratosis" refers to the rough, horny appearance of tissue.) Cervix Growth: Dysplasia Premalignant tissue in the cervix, the neck of the womb, may involve cells that begin to alter their shape and size, a condition known as dysplasia. ("Dys-" means "bad" and "-plasia" means "condition.") Such cells are present only in the outer layer of tissue. If those cells become cancerous, they attack the inner, deeper tissues. Factors that contribute to the development of cervical growths include sexual activity early in life, frequent sexual activity with many partners, herpes infections, inattentive health care, and multiparity (being the mother of more than one child). Lung Growth: Squamous Metaplasia Premalignant tissue in the lung can occur in the form of squamous metaplasia — flat, scaly, plate like cells with irregular shapes . ("Squamous" means "scaly" and "meta-" means "change.") If these cells turn cancerous, they invade deep tissue. Chronic damage to the lungs can contribute to the development of lung growths. Breast Growths: Abnormal Cells in Milk Ducts Premalignant tissue may occur in the milk ducts of the breasts in the form of cells that grow abnormally. Advancing age, a family history of breast tumors, diabetes, high blood pressure, exposure to radiation, and first-time motherhood after age 40 have all been implicated as risk factors for breast tumors. Mouth Growths: Leukoplakia and Erythroplakia Premalignant tissue in the mouth may appear as patches of white tissue (leukoplakia) or red tissue (erythroplakia). These formations appear on mucous membranes. If they do not go away after 10 to 20 days, the patient should have a doctor take a tissue sample (biopsy) for analysis.
* * *SYN: precancerous.
* * *pre·ma·lig·nant .prē-mə-'lig-nənt adj PRECANCEROUS
* * *pre·ma·lig·nant (pre″mə-ligґnənt) precancerous.
Medical dictionary. 2011.