‘En face’ ex vivo reflectance confocal microscopy to help the surgery of basal cell carcinoma of the eyelid

Background Fluorescence confocal microscopy (FCM) is a recent imaging technique for the examination of surgical cutaneous specimens and has been suggested as a fast alternative to Mohs micrographic surgery. Up-to-date it has been used in the fluorescence mode and with vertical sections of the specimen margins. The aim of this study was to evaluate FCM in the reflectance mode and with a horizontal (“en face”) scanning of the surgical specimen in a series of basal cell carcinoma (BCC) of the eyelid. Design Prospective consecutive cohort study performed at the University Hospital of Saint-Etienne, France. Participants 41 patients with 42 BCC of the eyelid Methods BCC were excised with a 2 mm wide clinically safe margin. The surgical specimens were analyzed under FCM in the reflectance mode and with an “en face” scanning in a perioperative setting in order to control at a microscopic level if the margins were free from tumor invasion. Histopathogical examination was later performed in order to compare the results. Main Outcome Measures Sensitivity and specificity of FCM for the presence of tumor-free margins. Results FCM results were consistent with histopathology in all cases (tumor-free margins in 40 out of 42 samples; sensitivity and specificity of FCM of 100%). Conclusions The FCM analysis in the reflectance mode and with an “en face” scanning can control tumor margins of eyelid BCCs and optimize their surgical management. This procedure has the advantage on FCM performed in the fluorescent mode of not needing any contrast agent to examine the samples.