State of the art of diagnostic technology for early-stage melanoma.

In the past few decades, rapid improvements in noninvasive optical technologies have revolutionized the diagnosis of early-stage melanoma. Current knowledge and limitations of these tools will be reviewed in this article. Dermoscopy has been recognized as the 'gold standard' in the screening phase. Digital dermoscopy monitoring and total-body photography are used to identify so-called 'featureless' melanoma only on the criteria of change over time. Automated instruments, as well as optical and nonmorphological methods, are still under development, and offer many opportunities to improve the speed and accuracy of the diagnosis of melanoma and/or to reduce the need for expertise. Despite a penetration depth limited to the upper dermis, the quasi-histological imaging achieved by in vivo reflectance confocal microscopy has been demonstrated to significantly aid diagnostic accuracy for selected melanocytic lesions. Future perspectives on diagnostic instrumentation will also be explored.