Book excerpt: Reflectance confocal microscopy enables lesions in skin to be examined without excision, but with improved diagnostic accuracy, assessment of dermoscopic-histologic correlation, assessment of surgical margins, as well as speed and convenience for the physician and patient. This extensively enlarged and updated text reviews the current and future state of the art for those involved with the diagnosis and treatment of skin tumors, with a greatly increased amount of material on the expected normal patterns of skin throughout life and on non-melanocytic tumors.