Tumor-like microenvironment in oral lichen planus: evidence of malignant transformation?

INTRODUCTION: Oral lichen planus (OLP) is a T-cell-mediated chronic inflammatory autoimmune disease affecting 0.1% to 4% of the world population. The WHO has already recognized it as an oral potentially malignant disorder. However, the reasons for the malignant transformation of OLP are far from being elucidated clearly. The purpose of this review is to clarify how the tumor-like microenvironment in OLP mediates its potentially malignant transformation. Areas covered: We review published articles on the microenvironment characteristics of tumors, the pathogenesis of OLP, and clinical studies of OLP. The main sources of literature derive from MEDLINE/Pubmed and Thomson Reuter's Web of Science. Expert commentary: The tumor-like microenvironment, including hypoxic, inflammatory, immune and acid microenvironment, greatly contributes to carcinogenesis of OLP patients. In order to effectively monitor the malignant transformation of OLP, future studies should focus on long-term follow-up and select important detection biomarkers.