Lentigines

Lentigines are macular hyperpigmentations in which the number of epidermal melanocytes is increased and there are no nests of melanocytes as are present, by definition, in nevi. The term "lentigo" is derived from the Latin "Ienz," meaning lens or lentil . Thus, the term in its original usage is clinical, referring to a small ovoid or lens­shaped pigmented spot. The term has come to be applied to larger pigmented lesions, especially those that recapitulate to a greater or lesser extent the histologic features of a lentigo simplex: basal proliferation of melanocytes arranged as single cells rather than in nests, typically but not always associated with elongation of the rete ridges. This pattern of melanocytic proliferation is termed "Ientiginous." Lentiginous melanocytic proliferation is seen in the macules of solar lentigo and lentigo simplex and in the macular or plaque components of lentiginous junctional and compound nevi, of lentiginous dysplastic nevi, and of lentiginous melanoma,

including lentigo maligna, acral and mucosal-Ientiginous types.