In Vivo Reflectance Confocal Microscopy in Dermatology

Imaging techniques capable of noninvasive, high-resolution, skin imaging in vivo have been the focus of recent attention in the dermatology field. These efforts are directed to improve the diagnostic accuracy of skin cancer, especially cutaneous melanoma. Reflectance confocal microscopy (RCM) is an innovative imaging tool that allows the analysis of the skin horizontally with a nearly histological resolution. Similar to dermoscopy images, real-time images obtained by RCM are oriented horizontal to the skin surface (optical transversal sections). Melanin provides strong contrast because of its high refractive index (1.7) relative to the surrounding epidermis. It has been applied in the clinical arena for the diagnosis of melanocytic and nonmelanocytic lesions where it has been proven to increase greatly the diagnostic accuracy when coupled with dermoscopy. Beyond its application in skin oncology, confocal microscopy can be useful to delineate the overall aspect of inflammatory skin disease and infectious ones. The main limitation of RCM is its relatively low penetration through the dermis; a maximum depth of 250-300. μm can currently be achieved, preventing imaging of structures located in the deep dermis and hypodermis. The main challenge is the interpretation of images. Specific photographic atlas, courses, and further development of teledermatology may solve this problem.