Intralesional 5-fluorouracil Injection for the Treatment of Oral Leukoplakia

Inclusion Criteria: * Adults, 18 years of age or older * Any gender, race, or ethnicity * Clinical diagnosis of oral leukoplakia and biopsy proven dysplasia (any grade) * Oral leukoplakia at least 1 cm in largest diameter * Ability to understand and willingness to sign a written informed consent document * Willingness to provide blood and tissue from diagnostic biopsies * Any smoking history is permitted Exclusion Criteria: * Pregnant or lactating women * Men and women unwilling to use contraception while on study * History of malignancy that required cytotoxic chemotherapy within the previous 3 months * Use of 5-FU (systemic or topical) within 3 months prior to study enrollment * History of allergic reaction or severe hypersensitivity to 5-FU and/or lidocaine * Presence of a condition or abnormality that in the opinion of the Investigator would compromise the safety of the patient or the quality of the data