Proliferative verrucous leukoplakia: Case study of 24 years and outcome of treatment with CO₂ laser

Background: Proliferative verrucous leukoplakia (PVL) is a rare and refractory form of oral leukoplakia. The etiology of PVL remains unknown. The lesion is characterized by a high rate of malignant transformation. There is no definitive treatment for PVL.

Methods: This case study presents a patient diagnosed in 2000 with a localized hyperkeratinized/verrucous lesion involving the facial gingivae of teeth #6-#8. Over the next 24 years, the lesion was biopsied five times. Further, two attempts to ablate the lesion with a CO₂ laser (10.6 µm wavelength) were performed. Both ablation treatments were unsuccessful as the lesion recurred and progressed to involve more areas of gingival tissue. To date, biopsy has not revealed transformation into verrucous or squamous cell carcinoma (SCCA).

Results: This case study demonstrates that two attempts at ablation of PVL using a CO₂ laser had no short- or long-term benefit. The patient eventually lost all maxillary teeth due to root caries and inability to maintain adequate oral hygiene. The PVL lesion currently involves the entire maxillary edentulous ridge, extending from the 2nd molar site to the opposite corresponding site. During the 24 years encompassed by this report, the patient has not experienced a malignant transformation.

Conclusion: The results of CO₂ laser ablation of the PVL lesion in this case provided no short- or long-term benefit. Given the potential for a sinister outcome, PVL patients require frequent clinical evaluation and biopsy for early detection of a malignant transformation into oral verrucous or SCCA.

Key points: Proliferative verrucous leukoplakia (PVL) is a clinical diagnosis and represents a refractory form of multifocal oral mucosal leukoplakia of unknown origin. Currently, there is no reliable and successful treatment for PVL. PVL may undergo transformation to a verrucous or squamous cell carcinoma, thereby necessitating frequent oral examination and biopsy of sinister-appearing mucosal sites.

Plain language summary: Proliferative verrucous leukoplakia (PVL) is a rare disorder that affects the gum tissue around the teeth. PVL is a pre-cancerous disorder for which the cause is unknown and there is no treatment that yields a consistently successful result. This case study presents a patient diagnosed in 2000 with PVL involving the facial gum tissue of the upper right cuspid, lateral, and central incisor teeth. Over the next 24 years, the lesion was biopsied five times and two attempts to irradicate the lesion with a CO₂ laser were performed. All attempts at treatment were unsuccessful and the lesion slowly progressed to involve more areas of gum tissue. The last biopsy taken in February 2024 did not reveal any areas of developing cancer. During the 24 years covered in this report, the patient did not develop oral cancer. However, treatment with the CO₂ laser afforded no measurable benefit. Given the potential for developing cancer of the gum tissues, PVL patients should receive frequent oral exams and periodic biopsies for the detection of early cancer.