Pilocytic astrocytoma

Case contribution: Dr Radhiana Hassan


  • A 13 years old girl
  • History of pilocytic astrocytoma grade 1,
  • Tumour resection done 5 years ago
  • On annual surveillance MRI
  • Noted to have increasing tumour size on last scan
  • Otherwise patient is asymptomatic
MRI brain in axial plane T2, T1 and T1+Gadolinium

MRI findings:

  • A predominantly cystic lesion is seen in the left cerebellum
  • It is hypointense on T1, hyperintense on T2 and shows minimal wall enhancement
  • Soft tissue component noted at its posterior wall which enhances post contrast
  • No calcification or bleed within the lesion
  • No surrounding oedema
  • No internal brain herniation

Diagnosis: Pilocytic astrocytoma (HPE proven)


  • Represent about 30% of paediatric gliomas
  • Second most common paediatric brain tumour
  • Indolent and slow growing
  • Location: optic chiasm>cerebellum>brain stem
  • Cerebellar lesion is usually cystic with intense mural nodule enhancement
  • Calcification seen in 10% of cases
  • There is strong association with NF1


Author: radhianahassan