[Essential melanic pigmentation of the mouth and the lips].

Lenticular or linear, buccal or labial, slate-coloured or melanic black spots are noticed in healthy subjects with no racial, hormonal or drug factor. Histological examination shows a pigmentary excess of the basement membrane without anomaly or dystrophy or nevus cells. Ultrastructural study shows a great number of intracyto-plasmic melanosomes, isolated or in group in all the keratinocytes in the third inferior part of the epidermis. No explanation can be given to this melanocyte hyperactivity. An excision can be done without danger for esthetical purpose.