What study is most appropriate for confirming a suspected diagnosis of leukoplakia?

To confirm a suspected diagnosis of leukoplakia, an incisional biopsy is the most appropriate study. This procedure involves removing a small section of the affected tissue for histopathological examination. The biopsy allows for the evaluation of the cellular characteristics of the lesion, which can help differentiate leukoplakia from other similar-looking conditions, such as oral cancers or dysplasia. By assessing the tissue under a microscope, healthcare providers can determine the nature of the lesion and whether it poses any malignant risk.

The incisional biopsy is critical because leukoplakia can range from benign keratosis to potentially precancerous or cancerous lesions. Identifying the specific characteristics of the cells helps guide management and treatment options.

The other options, while useful in different contexts, do not provide the definitive confirmation necessary for leukoplakia. Tzanck smear is typically used to detect herpes infections but cannot diagnose leukoplakia. Gram stain is employed to identify bacterial infections and is not applicable in this case. A potassium hydroxide wet prep is primarily used for fungal infections, specifically to identify dermatophytes, and would not assist in confirming leukoplakia.