[Encephalocraniocutaneous lipomatosis. A non-hereditary mosaic phenotype].

Encephalocraniocutaneous lipomatosis is a distinct neurocutaneous syndrome characterized by an extensive fatty tissue nevus of the scalp, protuberances of the cranial bones, lipodermoid of the conjunctiva, multiple intercranial lipomas, and porencephaly. A further case of this multisystem birth defect is reported. The patchy arrangement of lesions that is usually unilateral suggests a mosaic phenotype. The clinical criteria to distinguish this disorder from other mosaic neurocutaneous phenotypes, such as Schimmelpenning syndrome, Proteus syndrome, or Delleman syndrome, are outlined. To explain the origin of this nonhereditary genodermatosis, the concept of a lethal autosomal mutation that survives in a mosaic state is proposed.