LEUKOPLAKIA

precancerous tumour of the mucous membranes, most common in older men and usually seen on the lips or tongue, but also known to occur in women on the vagina or vulva. Leukoplakia first appears as a small, smooth, white spot but develops into a larger area of thickening with a rough texture and colour varying from white to gray; red areas within the leukoplakia pose a particularly high risk of becoming malignant. Older lesions may have numerous fissures and sores and tend to bleed after slight injury. Tertiary syphilis was a common cause of leukoplakia in the past. Most cases now result from external irritants, notably tobacco smoke. Other factors believed to contribute to this disease include exposure to sunlight, poor dental hygiene, and ill-fitting dentures. Leukoplakia may persist for many years without becoming malignant, but the high risk of squamous-cell carcinoma dictates complete removal of the tumour by surgery or freezing, as well as the elimination of all predisposing factors. Hairy leukoplakia is a white lesion on the tongue or mouth floor, often having rough hairlike projections. It often occurs in persons with acquired immune deficiency syndrome (AIDS) or the AIDS-related complex (ARC). The Epstein-Barr virus has been isolated from the lesions.