title: Classification of neurological abnormalities in children with congenital melanocytic naevus syndrome identifies magnetic resonance imaging as the best predictor of clinical outcome.
abstract: BACKGROUND
  The spectrum of central nervous system (CNS) abnormalities described in association with congenital melanocytic naevi (CMN) includes congenital, acquired, melanotic and nonmelanotic pathology. Historically, symptomatic CNS abnormalities were considered to carry a poor prognosis, although studies from large centres have suggested a much wider variation in outcome.
  
  
  OBJECTIVE
  To establish whether routine MRI of the CNS is a clinically relevant investigation in children with multiple CMN (more than one at birth), and to subclassify radiological abnormalities.
  
  
  METHODS
  Of 376 patients seen between 1991 and 2013, 289 fulfilled our criterion for a single screening CNS MRI, which since 2008 has been more than one CMN at birth, independent of size and site of the largest naevus. Cutaneous phenotyping and radiological variables were combined in a multiple regression model of long-term outcome measures (abnormal neurodevelopment, seizures, requirement for neurosurgery).
  
  
  RESULTS
  Twenty-one per cent of children with multiple CMN had an abnormal MRI. Abnormal MRI was the most significant predictor of all outcome measures. Abnormalities were subclassified into group 1 'intraparenchymal melanosis alone' (n = 28) and group 2 'all other pathology' (n = 18). Group 1 was not associated with malignancy or death during the study period, even when symptomatic with seizures or developmental delay, whereas group 2 showed a much more complex picture, requiring individual assessment.
  
  
  CONCLUSIONS
  For screening for congenital neurological lesions a single MRI in multiple CMN is a clinically relevant strategy. Any child with a stepwise change in neurological/developmental symptoms or signs should have an MRI with contrast of the brain and spine to look for new CNS melanoma.
authors.affiliation: Paediatric Dermatology, Great Ormond St Hospital for Children, London, U.K.
authors.forename: R
authors.initials: R
authors.lastname: Waelchli
authors.affiliation: Neurosciences, Great Ormond St Hospital for Children, London, U.K.|Neurosciences Unit, UCL Institute of Child Health, London, U.K.
authors.forename: S E
authors.initials: SE
authors.lastname: Aylett
authors.affiliation: Paediatric Dermatology, Great Ormond St Hospital for Children, London, U.K.
authors.forename: D
authors.initials: D
authors.lastname: Atherton
authors.affiliation: Paediatric Neurosurgery, Great Ormond St Hospital for Children, London, U.K.
authors.forename: D J
authors.initials: DJ
authors.lastname: Thompson
authors.affiliation: Paediatric Neuroradiology, Great Ormond St Hospital for Children, London, U.K.
authors.forename: W K
authors.initials: WK
authors.lastname: Chong
authors.affiliation: Paediatric Dermatology, Great Ormond St Hospital for Children, London, U.K.|Genetics and Genomic Medicine, UCL Institute of Child Health, London, U.K.
authors.forename: V A
authors.initials: VA
authors.lastname: Kinsler
mesh_terms: D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D020752:Neurocutaneous Syndromes / Q000145:classification* / Q000151:congenital / Q000473:pathology; D009508:Nevus, Pigmented / Q000145:classification* / Q000151:congenital / Q000473:pathology; D011379:Prognosis; D011446:Prospective Studies; D012878:Skin Neoplasms / Q000145:classification* / Q000151:congenital / Q000473:pathology