Reactive and Nonreactive White Lesions of the Oral Mucosa

White lesions within the oral cavity represent some of the most commonly encountered types of oral pathologic entities and may frequently cause diagnostic difficulty both clinically and his-tologically due to overlapping features between conditions. Consideration of both clinical history and appearance of the lesions is important in dis-tinguishing benign from potentially malignant or malignant lesions. Warning signs include high -risk location, sharply demarcated borders, thick-ened, plaque-like, papillary, or verrucous lesions, erythroplakia, asymmetry, or the presence of iso-lated lesions with no apparent source of trauma, large or enlarging size, multiple recurrences, or a pattern of marginal linear gingival leukoplakia (ring around the collar) are all important and must be recognized to provide appropriate management.