Combined reflectance confocal microscopy and optical coherence tomography to improve the diagnosis of equivocal lesions for basal cell carcinoma

Abstract

To the Editor: Small-sized (<10 mm) basal cell carcinomas (BCC) lacking specific dermoscopic features are challenging to diagnose. Even with reflectance confocal microscopy (RCM), the specificity remains low (37.5%-75.5%) 1 Kadouch D.J. Leeflang M.M. Elshot Y.S. et al. Diagnostic accuracy of confocal microscopy imaging vs. punch biopsy for diagnosing and subtyping basal cell carcinoma. J Eur Acad Dermatol Venereol. 2017; 31: 1641-1648 Crossref PubMed Scopus (22) Google Scholar due to limited imaging depth (200 μm), en face visualization, and a lack of melanin contrast for non/lightly pigmented lesions. 2 Jain M. Pulijal S.V. Rajadhyaksha M. Halpern A.C. Gonzalez S. Evaluation of bedside diagnostic accuracy, learning curve, and challenges for a novice reflectance confocal microscopy reader for skin cancer detection in vivo. JAMA Dermatol. 2018; 154: 962-965 Crossref PubMed Scopus (11) Google Scholar A novel combined handheld RCM and optical coherence tomography (OCT) device (RCM-OCT) has been developed to overcome these limitations. RCM-OCT provides real-time en face RCM and vertical OCT 3 Iftimia N. Yélamos O. Chen C.-S.J. et al. Handheld optical coherence tomography–reflectance confocal microscopy probe for detection of basal cell carcinoma and delineation of margins. J Biomed Opt. 2017; 22: 076006 Crossref PubMed Scopus (31) Google Scholar images simultaneously and has been shown to be confirmatory of a BCC diagnosis 4 Sahu A. Yélamos O. Iftimia N. et al. Evaluation of a combined reflectance confocal microscopy-optical coherence tomography device for detection and depth assessment of basal cell carcinoma. JAMA Dermatol. 2018; 154: 1175-1183 Crossref PubMed Scopus (34) Google Scholar ; however, it has not been evaluated for equivocal lesions in clinical settings. In a tertiary cancer center, we performed an IRB-approved prospective study to assess the performance of RCM-OCT compared to RCM alone for the diagnosis of lesions equivocal for BCC. We enrolled consecutive patients referred by dermoscopy experts for routine RCM imaging over a 1-year period.