Symptomatic neurocutaneous melanosis: mild clinical onset in a teenager

BMJ Case Rep. 2020 Nov 30;13(11):e235772. doi: 10.1136/bcr-2020-235772.

Abstract

Neurocutaneous melanosis (NCM) is a rare disorder characterised by giant or multiple melanocytic nevi and meningeal melanosis or melanoma. Onset of neurological symptoms is typically in children younger than 2 years and can be rapidly fatal. We present the case of a 13-year-old adopted girl presenting with numerous congenital melanocytic nevi and a seizure. She had no significant previous neurological history. Electroencephalogram showed epileptiform discharges over the right frontal region. MRI of the brain showed T1 hyperintensity in the bilateral amygdala and anterior temporal lobes with corresponding hyperintensity on T2 and fluid attenuated inversion recovery. There was no hydrocephalus. Along with the history of nevi, these imaging findings were concerning for NCM. The patient is being managed with levetiracetam and trametinib and shows no further neurological decline at 1-year follow-up, providing prognostic hope in this case of NCM.

Keywords: congenital disorders; neuroimaging; radiology.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Adolescent
  • Amygdala / diagnostic imaging
  • Amygdala / pathology
  • Anticonvulsants / therapeutic use*
  • Electroencephalography
  • Female
  • Humans
  • Levetiracetam / therapeutic use*
  • Magnetic Resonance Imaging
  • Male
  • Melanosis* / diagnosis
  • Melanosis* / drug therapy
  • Melanosis* / mortality
  • Mitogen-Activated Protein Kinase Kinases / antagonists & inhibitors*
  • Neurocutaneous Syndromes* / diagnosis
  • Neurocutaneous Syndromes* / drug therapy
  • Neurocutaneous Syndromes* / mortality
  • Nevus, Pigmented / congenital
  • Protein Kinase Inhibitors / therapeutic use*
  • Pyridones / therapeutic use*
  • Pyrimidinones / therapeutic use*
  • Seizures / drug therapy
  • Seizures / etiology
  • Temporal Lobe / diagnostic imaging
  • Temporal Lobe / pathology

Substances

  • Anticonvulsants
  • Protein Kinase Inhibitors
  • Pyridones
  • Pyrimidinones
  • trametinib
  • Levetiracetam
  • Mitogen-Activated Protein Kinase Kinases

Supplementary concepts

  • Neurocutaneous melanosis