Potentially malignant oval lesions in Northern Ireland: a 20-year population-based perspective of malignant transformation

This retrospective laboratory-based study investigates the potential for ma lignant transformation of oral mucosal lesions in a population of 1.6 milli on. Over the ttl-year period there were 745 patients diagnosed with primary intra-oral squamous cell carcinoma(OSCC), 165 patients with dysplasia and 1182 patients with 'nondysplastic' lesions (epithelial hyperplasia, hyperke ratosis epithelial atrophy, lichen planus and lupus erythematosus). Maligna nt transformation occurred in 15% of dysplasias and in 1% of 'non-dysplasti c' lesions at average intervals after diagnosis of 48 and 65 months respect ively, Only 6% of patients with OSCC had a preinvasive lesion biopsied, The se data suggest that white lesions are only rarely the pre-invasive phase o f OSCC. It is possible therefore that early changes are red, small or even microscopic with carcinoma developing without a clinically observable phase . More effective management strategies will require the development of tiss ue markers to enhance early detection.