MRI of an 8-year-old girl with ataxia shows a large well-defined cerebellar hemispheric lesion consisting of a fluid signal cyst with an intensely and homogeneously enhancing solid nodule along its wall. No surrounding oedema is present. The most likely diagnosis is:
- A Cerebellar haemangioblastoma
- B Pilocytic astrocytoma ✓
- C Medulloblastoma
- D Metastasis
Correct answer: B. Pilocytic astrocytoma
Explanation
In a child, a cystic cerebellar mass with a strongly enhancing mural nodule and minimal oedema is classic for juvenile pilocytic astrocytoma, a WHO grade 1 tumour. Haemangioblastoma can look identical but occurs almost exclusively in adults and in von Hippel-Lindau disease, so age decides this item. Medulloblastoma is a solid midline mass without this cyst and nodule pattern.
Reference: Osborn's Brain, 2nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.