Can basal cell carcinoma lateral border be determined by fluorescence diagnosis? Verification by Mohs micrographic surgery

Background: The preferential accumulation of 5-aminolaevulinic acid (ALA)-induced protoporphyrin IX (PpIX) in neoplastic cells supports its potential use in the photodetection of epithelial tumours through porphyrin fluorescence. Objective: To assess the validity of fluorescence diagnosis (FD) as an efficient pre-surgical in vivo imaging tool for defining the lateral boundaries of various types of basal cell carcinomas (BCCs). Methods: The BCC tumour area was determined for 27 patients using FD digitalized imaging system, where the accumulation of PpIX in tumour tissue in relation to normal tissue was measured. Subsequently, BCCs were excised according to the complete area defined by FD using Mohs micrographic surgery (MMS). Results: Of the 27 BCCs, the FD margin of the lesion coincided with the histopathological picture in 12 BCCs (44.44%). The mean value of accumulation factor (AF) was 2.7. Although 17 pigmented BCCs showed attenuated or absent fluorescence in the center, fluorescence at their periphery was used as a guide for excision, and statistically, the pigmentation of the BCCs showed no effect on the results of the FD efficacy (p =1.0). Conclusion: Fluorescence diagnosis of BCC may be beneficial as a guide to the safety margin needed before MMS. The safety margin is decided according to the FD tumour diameter in relation to the clinical tumour diameter. (C) 2016 Elsevier B.V. All rights reserved.