Comparing preoperative confocal mapping to surgical markings for facial lentigo maligna excision: a pilot study

Background: Lentigo maligna (LM) characteristically has an ill-defined margin and may require multiple excisions to achieve complete excision with 5 mm margins. In vivo reflectance confocal microscopy (RCM) is a non-invasive tool recognised as useful in the management of LM. The authors aimed to determine whether the use of RCM prior to surgical excision reliably increased the rate of complete excision when compared with standard surgical excision. Methods: This prospective pilot study included patients with biopsy-proven LM of the head and neck region who sought consultation for surgical management from May 2017 to May 2019 at the Victorian Melanoma Service, Melbourne. Patients were randomised to two groups based on the availability of RCM—Group 1, RCM-guided surgical excision, and Group 2, standard surgical excision. Outcomes were measured based on clinical markings and histopathological margins achieved and reported as RCM or surgical margin excess or deficit. Ethics approval for the study was obtained from the research governance unit of The Alfred Hospital, Melbourne. Results: Results demonstrated that RCM marking of lesion margins was in excess in 69 per cent of cases, in deficit in 22 per cent and accurate in nine per cent after histopathological analysis of the specimens. In comparison, lesions that were surgically marked were removed with margins in excess in 43 per cent of cases, in deficit in 11 per cent and accurate in 46 per cent. Conclusion: This pilot study demonstrates that RCM did not increase the accuracy of LM surgical excision in comparison with standard surgically marked excisions.