Precancerous condition

Under a precancerous condition is understood in medicine a tissue change that accompanies degeneration associated with a statistically increased risk of a malignant ( malignant). A precancerous condition can be congenital (eg, familial adenomatous polyposis ) or acquired (eg, actinic keratoses ). According to the statistical probability of the occurrence of cancer they are divided into facultative precancer and obligate precancerous lesions.

Optional precancer

From facultative precancerous lesions is when the risk of malignancy is a malignant tumor of less than 30 % and pass a ( long ) period of more than five years between the onset and degeneration of precancer. Examples of a facultative precancerous condition are ulcerative colitis, liver cirrhosis, including the two most common facultative precancerous lesions are actinic keratosis and leukoplakia of the mouth and the ear-nose - throat area.

Obligate precancer

Obligate precancerous lesions degenerate with higher probability ( > 30%) in a short span of less than five years to a malignant tumor. This is to be expected in the existing disease with an almost 100 -percent incidence of cancer. The familial adenomatous polyposis and Gardner syndrome are obligate the premalignant lesions of colon cancer. A very rare form of an obligatory precancerous lesion is the xeroderma pigmentosum. As an obligatory precancerous lesion of the oral mucosa, the erythroplakia is considered. The dysplastic cellular changes in the Cervical intraepithelial neoplasia grade III and carcinoma in situ ( CIS) of the cervix uteri are considered obligate precancerous lesion for cervical cancer.