[Oculodermal melanocytosis (nevus of ota) and blue nevus (author's transl)]

Report is made of a patient having concurrently an Ota nevus and a blue nevus. The dermal melanocytes showed a marked formation of large intracytoplasmatic vacuoles. Reference to the important role of an "extracellular sheath" is made. The nearly identical ultrastructural characteristics of dermal melanocytes in various dermal melanocyte disorders seems to imply a common pathological origin in their development.