LEUKOPLAKIA (leukoplakia; Greek leukos white + plax plate; synonym leykoplaziya) — the damage of mucous membranes which is characterized by different extent of keratinization of a cover epithelium. It is most often localized on a mucous membrane of an under lip of an oral cavity, especially cheeks, near a corner of a mouth and on the course of the line of a bite of teeth, and also on a vulva, is more rare — in the field of a balanus and a preputial bag at men, a clitoris, a vagina and a neck of uterus at women, in a circle of an anal orifice. The term «leukoplakia» for the first time offered in 1877 E. Schwimmer, the first a wedge, the description belongs to A. Bazen (1868). L. in an oral cavity for the first time in detail studied in 1883 Mr. Vidal (E. Vidal). Meets usually aged apprx. 30 years, however it is possible also at younger age.
Aetiology of L. it is not known. Its emergence on mucous membranes of an oral cavity is promoted by the factors having the irritating properties and defiant local inflammatory processes (e.g., the low-quality dentures destroyed and acting teeth, smoking, excessive alcohol intake of spices, etc.) - in a vulva of L. usually arises owing to an involutional mucosal atrophy. L. it can be shown as a peculiar defense reaction on various, preferential exogenous, influences; from endogenous etiol, factors a nek-ry role is played by disorders of functions went. - kish. a path, avitaminosis And yes In (all complex). Hereditary predisposition to L. Sleduyet's development is not excluded to consider also influence of infectious and thermal factors. L. can be a symptom various hron, inflammatory processes, such as syphilis, tuberculosis, mycoses, etc.
Allocate to Patogistologiya simple, or flat, and warty (leukokeratosis) of a form L. Histologically at a simple form the thickening of a multilayer flat epithelium due to expansion basal and granular layers, the phenomena is noted parakeratosis (see), hyperkeratosis (see) and acanthosis (see). And akantotichesky tyazh can get deeply into a derma with development of kruglokletochny infiltration around. At a warty form L. on a surface of an epithelium the V-shaped furrows filled with horn masses are formed, the thickening of an epithelium happens due to proliferation and expansion of a basal layer, disorder of an arrangement of epithelial cells to the phenomena of atypia. In a derma it is noted lymphocytic, plazmokletochny infiltration is more rare. Dermo-epidermalnaya the border becomes indistinct. L. it is accepted to consider as an optional pretumor disease though not all authors agree with it. Frequency of an ozlokachestvleniye of L., according to various researchers, widely varies — from 15 to 75%, a thicket in language that the wedge, forms is explained by various tendency to a malignancy various. The warty form malignizirutsya more often. Early gistokhy. signs of a malignancy of L. disappearance of a glycogen and the progressing reduction of content of RNA in the center are considered having a certain diagnostic importance.
Clinical picture of a simple form L. it is characterized by emergence of the centers of defeat (films, plaques) of white, whitish-gray color (tsvetn. fig. 1 — 3), enough dense to the touch. The sizes them seldom exceed 2 — 3 cm in the diameter, almost do not tower over the level of a mucous membrane. Borders are sometimes accurate, jagged, sometimes indistinct. Folds of a mucous membrane smooth out. At a warty form L. plaques tower over the level of a mucous membrane on several millimeters (tsvetn. fig. 4). Color of educated plaques from chalk, nacreous-white till the color (tsvetn. fig. 5). At localization on a lip, language morbidity, burning sensation, a petrifaction, disturbance of flavoring feelings is often observed. At an injury bleeding is observed.
Wedge, current of L. can be complicated by fracturing, the ulcers inclined to recuring.
the Diagnosis is made on the basis a wedge, the data confirmed histologically. The differential diagnosis is carried out with red flat it is deprived (see. Deprive red flat ), lupus erythematosus (see), a giperkeratotichesky nevus (see. Nevus ), Bowen's disease (see. Bowen disease ), desquamative glossitis (see) — so-called geographical language (the defeats which are available at the same time — the multiple plaques similar to the card merging among themselves — less saturated color and almost without keratinization on a surface), kraurozy vulvas (see) and kraurozy a penis (see. Penis ), more rare a hard ulcer and secondary syphilides on mucous membranes (see. Syphilis ), etc.
Treatment is directed first of all to an exception of the factors promoting development of L. Medicamentous therapy comes down to introduction of high doses of vitamin A and In 2 . Vitamin A is appointed also locally in the form of applications. At a warty form L., especially at suspicion on a malignancy, operational treatment is shown. At L. successfully apply a cryolysis (see. Cryosurgery ), electrothermic coagulation (see. Diathermocoagulation ), sometimes radiation therapy. At the developing phenomena of a malignancy treatment is carried out, as at planocellular cancer of mucous membranes.
The forecast and Prevention
the Forecast depends from a wedge, forms L. It is optimum at flat L.
Prevention: sanitation of an oral cavity, careful stomatol, preparation for prosthetics, smoking cessation, timely treatment went. - kish. frustration, avitaminosis. Sick L. shall be under constant dispensary observation.
See also Pretumor diseases .
Bibliography: Mashkilleyson A. L. Precancer of a red border and mucous membrane of a mouth, M., 1970, bibliogr.; To 1 e e-m a n W. Geschwiilste der Haut, Lpz., 1977; Lever W. F. a. Schaumburg-Lever G. Histopat.hology of the skin, Philadelphia — Toronto, 1975.
S. M. Parshikova.