A Case of Proliferative Verrucous Leukoplakia With Insidious Transformation Into Oral Verrucous Carcinoma

Proliferative verrucous leukoplakia (PVL) is a rare and aggressive subtype of oral leukoplakia characterized by multifocal progression, frequent recurrence, and a high risk of malignant transformation.Diagnosis is often delayed due to non-linear clinical course and evolving histopathologic features.We report a case of PVL-associated verrucous carcinoma in a 68-yearold non-smoking woman.The lesion initially presented as a localized elevated plaque on the left buccal mucosa and was diagnosed as squamous papilloma.Over a 6-year period, it progressively expanded with prominent verrucous changes, and repeated biopsies showed variable histologic findings.Wide transoral excision was performed, and the final pathology revealed verrucous carcinoma with a pushing growth pattern without cytologic pleomorphism or infiltrative invasion, which is consistent with the malignant transformation of long-standing PVL.This case highlights the diagnostic challenges of PVL and underscores the importance of prioritizing clinical suspicion over isolated histologic findings.