Proliferative Verrucous Leukoplakia: An Expert Consensus Guideline for Standardized Assessment and Reporting

Area of Science:

• Oral Pathology
• Histopathology
• Oncology

Background:

• Proliferative verrucous leukoplakia (PVL) exhibits diverse terminology, leading to inconsistent clinical management.
• Standardized diagnostic criteria are needed for accurate assessment and reporting of PVL lesions.

Purpose of the Study:

• To establish an expert consensus guideline for the standardized assessment and reporting of PVL-related lesions by pathologists.
• To develop consistent histopathologic criteria and descriptive terminology for PVL.

Main Methods:

• Review of 299 biopsies from 84 PVL patients across six institutions with a minimum 36-month follow-up.
• Expert working group of oral and maxillofacial and head and neck pathologists analyzed microscopic features and clinical photographs.
• Whole slide digital imaging (WSI) review of selected cases by consensus conference members, including non-PVL mimics as controls.

Main Results:

• Highest inter-observer agreement was achieved for 'corrugated ortho(para)hyperkeratotic lesion, not reactive' and 'squamous cell carcinoma' (SCC).
• Moderate agreement was found for 'bulky hyperkeratotic epithelial proliferation, not reactive' lesions.
• 35 out of 48 cases showed moderate or higher agreement among observers.

Conclusions:

• An expert consensus guideline recommends standardized histopathologic criteria for PVL, categorizing lesions into three groups: 'corrugated ortho(para)hyperkeratotic lesion, not reactive,' 'bulky hyperkeratotic epithelial proliferation, not reactive,' and 'suspicious for,' or 'squamous cell carcinoma.'
• Classification combining clinical findings with these histologic categories is encouraged for standardized reporting, research, and clinical management guidance.