TWO GRADING SYSTEMS FOR ORAL EPITHELIAL DYSPLASIA IN ORAL POTENTIALLY MALIGNANT DISORDERS: A CLINICOPATHOLOGICAL STUDY

Abstract

Objectives To classify oral epithelial dysplasia (OED), defined by the WHO, and binary grading systems in oral potentially malignant disorders (OPMDs), besides associating sociodemographic and histopathological features of these OPMDs. Study Design Records and slides of 65 cases compatible with clinicopathological diagnoses of OPMDs were evaluated for both classification systems and submitted to bivariate analysis. Results Middle-aged white men, non-smokers, and non-drinkers predominated. Smoking was associated with high-risk lesions by the binary system (p=0.036) and oral leukoplakia (p=0.003). The cases graded as mild-OED and severe-OED by the WHO system (85.7%) were reclassified as low-risk and high-risk respectively by the binary system. By contrast, 61.8% of moderate-OED cases were reclassified as low-risk for malignant transformation. Abnormal variation in cell size and shape, increased number and size of nucleoli, drop-shaped rete ridges, loss of epithelial cell cohesion, and abnormally superficial mitotic figures were statistically significant (p<0.05) in both grading systems. Cytological changes were significant in the WHO system, whereas architectural changes were significant in the binary system. Conclusions These are important histopathological features that should be taken into consideration when grading OED. Smoking was strengthened by the binary system as a risk factor for developing oral leukoplakia and its progression to malignancy. CNPq. To classify oral epithelial dysplasia (OED), defined by the WHO, and binary grading systems in oral potentially malignant disorders (OPMDs), besides associating sociodemographic and histopathological features of these OPMDs. Records and slides of 65 cases compatible with clinicopathological diagnoses of OPMDs were evaluated for both classification systems and submitted to bivariate analysis. Middle-aged white men, non-smokers, and non-drinkers predominated. Smoking was associated with high-risk lesions by the binary system (p=0.036) and oral leukoplakia (p=0.003). The cases graded as mild-OED and severe-OED by the WHO system (85.7%) were reclassified as low-risk and high-risk respectively by the binary system. By contrast, 61.8% of moderate-OED cases were reclassified as low-risk for malignant transformation. Abnormal variation in cell size and shape, increased number and size of nucleoli, drop-shaped rete ridges, loss of epithelial cell cohesion, and abnormally superficial mitotic figures were statistically significant (p<0.05) in both grading systems. Cytological changes were significant in the WHO system, whereas architectural changes were significant in the binary system. These are important histopathological features that should be taken into consideration when grading OED. Smoking was strengthened by the binary system as a risk factor for developing oral leukoplakia and its progression to malignancy. CNPq.