Background: Encephalocraniocutaneous lipomatosis (ECCL) is a sporadically occurring neurocutaneous disorder of unknown aetiology. It has repeatedly been discussed as a localised form of Proteus syndrome. In 2006, the first larger series of patients has been reported by Hunter and diagnostic criteria have been proposed.
Aims: To better define the phenotypic spectrum and natural history of ECCL and to revise diagnostic criteria.
Methods: 54 patients with ECCL have been reviewed.
Results: Eye anomalies (mainly choristomas) and skin lesions (non-scarring alopecia, nevus psiloliparus, subcutaneous fatty masses, nodular skin tags, aplastic scalp defects) may be uni- or bilateral and occur in a consistent pattern. CNS anomalies consist of intracranial and intraspinal lipomas, congenital abnormalities of the meninges, and putative focal vascular defects resulting in highly asymmetrical changes. About 2/3 of patients have a normal development or mild retardation only, and half of them have seizures. A correlation between the extent of CNS anomalies and neurological features could not be established. Aortic coarctation, progressive bone cysts and jaw tumours may be associated.
Conclusions: Revised diagnostic criteria are proposed. ECCL is considered to differ in particular from Proteus syndrome, but oculoectodermal syndrome is possibly a mild variant. Pathogenetically, mosaicism for a mutated autosomal gene involved in multiple mesenchymal tumours and vasculogenesis, with or without a second hit event is discussed.