Diffuse lentiginosis in a patient with Werner's syndrome--a possible association with incomplete leopard syndrome.

A classical case of Werner's syndrome is described. In addition to the numerous skin changes that are typically associated with Werner's syndrome, our patients also displayed diffuse lentiginosis, and several of the clinical features of leopard syndrome. Histopathological and ultrastructural findings from a hyperpigmented macule displayed the typical features of a simple lentigo. A striking feature was the presence of melanosomes in Langerhans cells as has been reported in the leopard syndrome. A possible generalized mesodermal defect has been suggested in Werner's syndrome, while the basic defect in the leopard syndrome is thought to be of neuroectodermal origin with pleiotropic changes in the organs derived from the mesoderm. Our patient, with incomplete leopard syndrome and typical Werner's syndrome, may be an example of an association of genetic defects affecting both tissues of neuroectodermal and mesodermal origin.