ABSTRACT
The term melanotic macules summarize all skin lesions caused by hyperpigmentation of the basal keratinocytes and a minimal increase of melanocytes in histology. This group includes all types of lentigines of the genital and oral mucosa, lips, and solar lentigines, as well as reticulated black solar lentigo, also known as ink-spot lentigo. Typical dermoscopic clues of lentigo maligna helpful in the differentation from solar lentigo are asymmetrically pigmented follicles, an annular-granular pattern, a circle within the circle, and a gray pseudonetwork. Ink-spot lentigines typically show a reticulated pattern in dermoscopy with dark brown or black "broken-up" lines. It is believed that the pigment network seen with dermoscopy is due to a high concentration of mast cell growth factor stimulating melanocyte proliferation and melanogenesis, thus leading to hyperpigmentation of basal keratinocytes. Dermoscopy of melasma shows a diffuse reticular pigmentation in various shades of brown and more intense teleangiectasies compared with normal skin.
