A 9-year-old boy presents with morning headache and papilloedema. MRI shows a large cystic lesion in the right cerebellar hemisphere with an intensely enhancing solid mural nodule, and a small satellite cyst. There is no associated syndromic stigmata. The most likely diagnosis is:

• A Pilocytic astrocytoma ✓
• B Medulloblastoma
• C Haemangioblastoma
• D Ependymoma

Explanation

Juvenile pilocytic astrocytoma is the commonest childhood cerebellar tumour and has the classic cyst with enhancing mural nodule pattern, often with smaller daughter cysts. It is a WHO grade 1 tumour with excellent prognosis after resection. Haemangioblastoma can look identical but occurs almost exclusively in adults, and in a child should raise von Hippel-Lindau disease suspicion only if multiple. Medulloblastoma is a solid midline vermian mass with diffusion restriction.

Reference: Osborn's Brain: Imaging, Pathology, and Anatomy, 2nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.