(62) Disparities in Reporting Oral Potentially Malignant Disorders Among Head and Neck Pathologists and Oral and Maxillofacial Pathologists

Abstract:

Background: Oral potentially malignant disorders (OPMDs) are a group of conditions identified in the literature as having the potential to progress to oral squamous cell carcinoma (OSCC). The histological recognition and grading of epithelial dysplasia play a critical role in assessing the risk of malignant transformation, providing clinicians with essential prognostic information. However, the process of grading epithelial dysplasia is inherently subjective and often marred by inconsistencies. Studies have documented poor inter- and intra-observer agreement among pathologists, which may arise from variations in training, interpretation of histopathological criteria, and differences in familiarity with oral mucosal subsite morphology.

The primary aim of this study was to identify specific areas of variance in the assessment of dysplasia and its grading by experienced pathologists from two subspecialties: oral pathologists (OMP) and head and neck pathologists (H&N). Understanding these differences could inform strategies to improve diagnostic consistency. Additionally, the study sought to evaluate the feasibility of using whole-slide digital imaging as a tool for conducting large-scale concordance studies and facilitating standardized training.

Design: To address the study aims, 9 representative samples were selected from various anatomical subsites within the oral cavity, including the alveolar mucosa, lateral and ventral tongue, and buccal mucosa. The specimens represented a spectrum of histological diagnoses, ranging from benign or reactive squamous lesions to dysplastic changes and minimally invasive squamous cell carcinoma.

The samples were digitized using the Keyence BZ-X Series Microscope (Keyence Corp., USA) to produce high-resolution whole-slide digital images. These images were then distributed to three experienced OMPs and three H&N pathologists for independent assessment. Each pathologist evaluated the cases for the presence and grade of epithelial dysplasia, using the traditional three-tier system: mild, moderate, and severe dysplasia.

Results: The results highlighted notable trends and differences:
Consistency in High-Grade Dysplasia and Invasive Carcinoma: Among the H&N pathologists, there was strong agreement in identifying high-grade dysplasia and invasive carcinoma. For other dysplastic lesions, variability was limited to one-step differences in grading. Similar consistency was observed among the OMPs.
Discrepancies in Mild Dysplasia: A significant divergence was observed in the grading of mild dysplasia between the two groups of pathologists. H&N pathologists frequently reported an absence of dysplasia in cases where OMPs identified mild dysplasia. This discrepancy underscores potential differences in diagnostic thresholds or interpretative criteria between the subspecialties.

Conclusion: A diverse range of OPMDs is recognized within the oral cavity, each with distinct etiologies and histological appearances. Variability in the morphology of oral mucosa across subsites adds complexity to the assessment process, contributing to inconsistencies in dysplasia grading.

The findings of this study emphasize the need for a unified grading system to improve diagnostic consistency. Reducing the traditional three-tier dysplasia classification (mild, moderate, severe) to a simplified two-tier system (low-grade and high-grade) could significantly enhance concordance among pathologists across subspecialties.

Additionally, whole-slide digital imaging offers a practical and effective platform for both diagnostic evaluation and pathologist training. By incorporating subspecialty-specific training programs that leverage digital imaging technology, pathologists can achieve improved recognition of squamous dysplasia and greater concordance in grading across oral subsites.

Future research should focus on validating these findings in larger cohorts and exploring the integration of adjunctive tools, such as molecular markers and artificial intelligence, to further standardize and enhance the grading of epithelial dysplasia in the oral cavity.
Figure 1. Representative images analyzed by the surveyed observers: (A) Low-grade dysplasia, (B) Moderate-grade dysplasia, (C) High-grade dysplasia, and (D) Invasive squamous cell carcinoma. All images were stained using Hematoxylin and Eosin (H&E).