Photodynamic therapy combined with laser drilling successfully prevents the recurrence of refractory oral proliferative verrucous leukoplakia.

Oral proliferative verrucous leukoplakia is a potentially malignant disorder with high rates of recurrence and malignant transformation. Proliferative verrucous leukoplakia is often refractory to various treatments, including topical drugs, surgical resection, cryotherapy, and laser therapy. Topical 5-aminolevulinic acid-mediated photodynamic therapy is an innovative and effective treatment for potentially malignant oral disorders and has the potential to control the recurrence of precancerous lesions and cancer. Various pre-treatments or combined therapies have been proposed to increase the efficacy of topical 5-aminolevulinic acid-mediated photodynamic therapy, especially for large, thick, or highly keratinised lesions. We report a case of refractory proliferative verrucous leukoplakia in a 58-year-old female patient who showed rapid recurrence within 1 week of topical 5-aminolevulinic acid-mediated photodynamic therapy despite pre-treatment with microneedle puncture, combined intralesional injection of 5-aminolevulinic acid, and shortened treatment interval. We applied three sessions of topical 5-aminolevulinic acid-mediated photodynamic therapy combined with diode laser drilling pre-treatment at 1-week intervals, which successfully eradicated the lesions without any adverse effects and without any signs of recurrence at the 10-month follow-up. Topical 5-aminolevulinic acid-mediated photodynamic therapy combined with diode laser drilling pre-treatment is safe and well-tolerated and could have synergistic efficacy against refractory oral proliferative verrucous leukoplakia.