In vivo reflectance confocal microscopy of supernumerary nipple and differential diagnosis from melanocytic lesions.

Supernumerary nipples (SN) represent a developmental abnormality present in 1-6% of the population at large. Although the clinical diagnosis is as a rule easy, this lesion can mimic lentigos and melanocytic nevi, with which it may share some dermatoscopic features. Reflectance confocal microscopy is a new imaging technique that allows in vivo visualization of normal and pathologic skin structures, and is especially useful in the diagnosis of pigmented skin lesions. The reflectance confocal microscopic features of SN are described here, and the potential usefulness of this technique in the differential diagnosis of this lesion from its main clinical mimics is briefly discussed.