[Ocular and cutaneous melanosis associated with the Sturge-Weber syndrome: clinical, histological, and ultrastructural studies of one case (author's transl)].

A 3 year old portuguese boy with the Sturge-Weber syndrome also had oculocutaneous melanosis. The cutaneous melanosis extended to more than 50 p. 100 of the body surface. Hands, feet and the face were spared. The abnormal pigmentation of the eyes involved the sclerae bilaterally. Clinically, the cutaneous hypermelanoses most likely represented a widespread aberrant mongolian spot. Histological study of the hyperpigmented skin revealed dermal melanocytes in the superficial and mid-dermis. Ultrastructural study showed that most of the dermal melanocytes were loaded with mature melanosomes. All development stages of melanosomes were observed in some of them. Average melanosomal size in the dermal melanocytes was slightly increased when compared to that of melanosomes in epidermal keratinocytes. From this case and from a review of the literature, the authors suggest that the association between the Sturge-Weber syndrome and disturbances of the melanin pigmentation of the skin and eye is probably not coincidental. An embryologic abnormality, affecting both the neural crest (from where melanoblasts originate) and the primary vascular plexus may explain such an association. Various disorders, including nevus of Ota, nevus Flammeus, the Sturge-Weber syndrome associated with ocular and cutaneous pigmentary abnormalities and the Sturge-Weber syndrome in the complete or incomplete forms, may represent the clinical picture of the same embryologic disturbance. The clinical picture might be related to the time at which it acts, the receptivity of the various structures and their level of differentiation.