Pediatric Neurocutaneous Melanosis

  • Etiology: Congenital dysplasia of melanoblasts which are of neural crest cell origin
  • Imaging MRI:
    — Hydrocephalus
    — Syringomyelia
    — T1WI: Hyperintensity involving mesial temporal lobes or ventral pons and medulla or cerebellum or inferior frontal lobes due to melanocytes tracking along perivascular spaces
    — T1WI post contrast: Diffuse meningeal enhancement of brain and spine
  • DDX:
  • Complications: Malignant transformation of cutaneous nevi in 2-13% to melanoma, malignant transformation of CNS melanosis in up to 50%
  • Treatment:
  • Clinical: Phakomatosis characterized by multiple congenital cutaneous nevi and meningeal melanocytosis or meningeal melanomatosis

Radiology Cases of Neurocutaneous Melanosis

MRI of neurocutaneous melanosis
Axial T1 MRI without contrast of the brain shows asymmetrically increased signal intensity in the right mesial temporal lobe (left) and in the right cerebellar hemisphere (right).

Clinical Cases of Neurocutaneous Melanosis

Clinical image of neurocutaneous melanosis
Clinical image shows a giant nevus covering the entire back.