Encephalocraniocutaneous lipomatosis.

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 large series of patients was reported, and diagnostic criteria were proposed.

AIMS: To better define the phenotypic spectrum and natural history of ECCL and to revise diagnostic criteria.

METHODS: 54 patients with ECCL were reviewed.

RESULTS: Eye anomalies (mainly choristomas) and skin lesions (non-scarring alopecia, naevus psiloliparus, subcutaneous fatty masses, nodular skin tags, aplastic scalp defects) may be unilateral or bilateral and occur in a consistent pattern. Central nervous system anomalies consist of intracranial and intraspinal lipomas, congenital abnormalities of the meninges, and putative focal vascular defects resulting in highly asymmetrical changes. About two-thirds of patients have a normal development or mild retardation only, and half of them have seizures. No correlation between the extent of central nervous system anomalies and neurological features could be established. Aortic coarctation, progressive bone cysts and jaw tumours may be associated.

CONCLUSIONS: Revised diagnostic criteria are proposed. ECCL is considered to differ from Proteus syndrome in particular, 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.