Cancerisation within the oral cavity: The use of ‘field mapping biopsies’ in clinical management

SummaryField cancerisation within the oral cavity risks multiple primary tumour development. Whilst multi-focal disease may ultimately affect up to 24% of oral cancer patients, a particular management problem is encountered with those patients presenting with pan-oral dysplasia. In an attempt to characterise the extent of dysplasia and to quantify the risk of malignant change, examination under anaesthesia (EUA) and multiple, ‘field mapping biopsies’ were carried out for 16 consecutive patients presenting with pan-oral disease. Seventy lesions, predominantly homogenous leukoplakias, were biopsied primarily showing hyperkeratosis or mild dysplasia histologically. More significant dysplasia was seen to affect the faucial pillars, floor of mouth and ventral tongue. Interventional CO2 laser surgery was used to excise 11 severely dysplastic lesions in six patients. Field mapping appears effective in the initial identification and treatment of the most significant areas of dysplasia in patients with multi-focal precancer. Longitudinal, multi-centre trials are now required.