Leukoplakia is a white patch on the oral or lingual mucosa, classified into benign white hyperkeratosis and premalignant leukoplakia based on its tendency for malignant transformation. The causes are as follows: white hyperkeratosis is mostly induced by external factors, primarily local mechanical, chemical, physical, and inflammatory stimuli. Premalignant leukoplakia is mainly caused by intrinsic individual predispositions, which vary from person to person. Under the same conditions, some individuals are more prone to cancer. This intrinsic predisposition is associated with genetics, immunosuppression, immunodeficiency, and nutritional deficiencies such as vitamins A and E.

bubble_chart Pathological Changes

1. Epithelial simple hyperplasia: Hyperkeratosis or parakeratosis of the surface epithelium. The granular layer is prominent, the prickle cell layer shows hyperplasia, and the epithelial rete ridges are enlarged. The connective tissue contains varying amounts of inflammatory cell infiltration. There is no tendency for malignant transformation, and the leukoplakia gradually thins and disappears after the removal of stimulating factors. Homogeneous leukoplakia belongs to this type of pathological change.
2. Epithelial dysplasia: The epithelium shows marked proliferation, with abnormal keratinization and atypical hyperplasia of epithelial cells, or even malignant transformation, such as changes in the polarity of basal cells. The epithelial stratification is irregular, the arrangement is disordered, mitotic figures are increased, nuclear chromatin is increased, nuclei are hyperchromatic, and nucleoli are enlarged. Dysplastic epithelium confined within the epidermis with an intact basement membrane can be considered carcinoma in situ, while involvement and breach of the basement membrane indicate early invasive carcinoma. Verrucous, granular, and erosive types all have a tendency for malignant transformation and require special attention during follow-up observation.

bubble_chart Clinical Manifestations

White patches on the tongue mostly occur on the dorsum, ventral surface, or margins of the tongue. The patches have clearly defined borders and are slightly raised above the mucosal surface, appearing milky white, grayish-white, or slightly yellowish-white. The lesion surface may be rough, uneven, or exhibit granular hyperplasia, verrucous protrusions, or erosion. Some reddened areas may also be scattered within the white patches.

Based on clinical manifestations, white patches can be classified into four types:

1. Homogeneous leukoplakia: The lesion appears as a white patch, slightly raised above the mucosal surface, with a somewhat rough, wrinkled-paper-like texture. It may be asymptomatic or cause a dry, rough sensation.
2. Verrucous proliferation: The white patch is thick and elevated, with a verrucous surface and a hard, rough texture.
3. Granular type: Small, raised white granular keratotic changes are present on a reddened mucosal surface, resembling villi.
4. Erosive type: The white patch exhibits erosion, possibly with ulcer formation, accompanied by significant pain.

bubble_chart Treatment Measures

1. Simple epithelial hyperplasia or simple leukokeratosis should be treated by removing all local irritants, and smokers should quit smoking.
2. For leukoplakia suspected of malignant transformation, such as verrucous, granular, and erosive sexually transmitted disease changes, surgical excision, cryotherapy, or CO₂ laser therapy should be performed. Patients who have undergone treatment should be regularly followed up to detect and treat any recurrence early.
3. 0.3% tretinoin ointment: Topical application for one to several weeks can lead to the regression of leukoplakia. Tretinoin inhibits epithelial keratinization. Lesions that regress may recur after discontinuation, but tretinoin remains effective upon reuse.
4. Vitamin A and Vitamin E: Vitamin A helps maintain the integrity and health of epithelial tissue structure, and some believe it plays a role in preventing epithelial malignant transformation. Vitamin E has a beneficial effect on body metabolism and exhibits strong antioxidant activity, which helps prevent the oxidation of Vitamin A and promotes its absorption. Vitamin A is taken orally at 250,000 U three times daily, and Vitamin E at 50 mg three times daily.