Confocal microscopy in the diagnosis and management of non-pigmented skin tumors (which, when, and when not)

Reflectance confocal microscopy (RCM) features diagnosing a solitary pink lesion include the presence of melanocytic nesting, basaloid tumor islands, keratinocytic atypia, and vascular structures. RCM is a useful tool to classify a given solitary pink tumor lacking clear-cut clinical and dermoscopic diagnostic features. RCM is a novel imaging tool that provides in vivo detailed information on architecture and cytology similar to histopathology. The major source of contrast in RCM images is provided by melanin that appears very bright, even if present in very small quantities. When dealing with a solitary pink lesion, several differential diagnoses have to be taken into account, considering both melanocytic and nonmelanocytic neoplasms. The RCM analysis of a given lesion, which should include the imaging of three anatomic levels (epidermis, dermoepidermal junction, and dermis), can reveal the presence of junctional or dermal melanocytic nesting, thus allowing one to establish the melanocytic nature of the tumor.