Exophytic Verrucous Hyperplasia of the Oral Cavity - Application of Standardized Criteria for Diagnosis from a Consensus Report

Verruco-papillary lesions (VPLs) of the oral cavity described in the literature involve a spectrum of conditions including squamous papilloma, verruca vulgaris, focal epithelial hyperplasia, condyloma, proliferative verrucous leukoplakia and verrucous carcinoma. A majority of the VPLs are slow growing, benign in nature and have a viral aetiology. Virus associated benign mucosal outgrowths are not too difficult to diagnose either clinically or by microscopy. Apart from virus-associated lesions, VPLs harboring malignant potential or behaviour such as verrucous carcinoma, proliferative verrucous leukoplakia, oral verrucous hyperplasia (OVH), oral papillary squamous cell carcinoma (PSCC) and oral conventional squamous cell carcinoma with papillary features (CSCC) need to be further clarified for better understanding of their predictable biologic behavior and appropriate treatment. Current understanding of potentially malignant VPLs is perplexing and is primarily attributed to the use of confusing and unsatisfactory terminology. In particular, the condition referred to as oral verrucous hyperplasia (OVH) poses a major diagnostic challenge. OVH represents a histopathological entity whose clinical features are not well recognised and is usually clinically indistinguishable from a verrucous carcinoma and a PSCC or a CSCC. A consensus report published by an expert working group from South Asia as an outcome of the 'First Asian Regional Meeting on the Terminology and Criteria for Verruco-papillary Lesions of the Oral Cavity' held in Kuala Lumpur, Malaysia, recognised the clinical description of these OVH as a new entity named 'Exophytic Verrucous Hyperplasia'. Previously described clinical features of OVH such as the 'blunt' or 'sharp' variants; and the 'mass' or 'plaque' variants can now collectively fall under this newly described entity. This paper discusses in detail the application of the standardized criteria guidelines of 'Exophytic Verrucous Hyperplasia' as published by the expert group which will enable clinicians and pathologists to uniformly interpret their pool of OVH cases and facilitate a better understanding of OVH malignant potential.