Oral Potentially Malignant Epithelial Lesions and Associated Risk in the Contralateral Mucosa

Statement of the problem: Early detection of potentially malignant epithelial lesions (PMELs) is aimed at improving survival rates as carcinogenesis is a multistep process and prevention is possible if these lesions are detected at an early and reversible stage of the disease. Objectives: This prospective clinical study was designed to determine the prevalence of bilateral mirror-image PMELs in patients presenting with unilateral PMELs clinically. A modified brush biopsy technique was employed to detect early cytological epithelial changes if any, in the contralateral normal oral mucosa. Materials and method: Sixty individuals presenting with unilateral PMELs were selected for this study. These comprised 30 (50%) Indians, 24 (40%) Chinese, 5 (8.3%) Malays and one (1.7%) Nepalese. All selected cases had histopathological confirmation of their primary existing lesion(s) as inclusion criteria in this study. Cases which had subsequently presented with a lesion contralateral to the existing lesion were also subjected to scalpel incisional biopsy on this second lesion. The remaining cases which presented with a unilateral PMEL at the time of this clinical study were subjected to a brush biopsy on the clinically normal looking mucosa contralateral to the existing lesion. Results: A total of 70 lesions were detected in 60 patients. The most common PMEL found was oral lichen planus. Of the 60 patients studied, 26 exhibited mirror-image lesions either metachronously (73%) or synchronously (27%). The remaining cases that had undergone brush biopsy on the contralateral side to the existing PMEL yielded normal histological results. Conclusions: Present findings demonstrated that patients presenting with PMELs in the upper aerodigestive tract are at greater risk of developing a second lesion most probably on the contralateral mirror-image site. However the efficacy of brush biopsy method in detecting epithelial changes remained inconclusive due to the small sample examined.