[Melanosomes, melanocytes and keratinocytes in the human epidermis in incontinentia pigmenti].

A functioning epidermal melanin unit implies a melanocyte capable of transferring melanosomes to keratinocytes; this requires not only melanocytes with adequate dendrites but also "receptive" keratinocytes. Skin with incontinentia pigmenti was examined by electron microscopy. Premelanosomes were occasionally found within keratinocytes and deposits of extracellular granular material that came from vacuolar degeneration of keratinocytes adjacent to melanocytes.