White lesions in the oral mucosa are considered abnormal findings because they may indicate pathological changes such as leukoplakia, candidiasis, or early malignancy. Unlike the normal pink, moist, and elastic mucosa, white patches suggest an underlying issue that requires further evaluation. These lesions can signify keratosis, fungal infection, or dysplasia, all of which warrant clinical attention. Early identification of such abnormalities is crucial for prompt diagnosis and management to prevent progression to serious conditions.

Reference: Oral Pathology, Neville et al., 4th Edition.