Case contribution: Dr Radhiana Hassan
Clinical:
- A 54 years old lady with atypical meningioma.
- Presented with seizures and diagnosed 4 years ago. Tumour excision done. HPE: Atypical meningioma.
- Post operative MRI one year later shows a small residual tumour
- After two years, patient presented with new seizures and MRI shows recurrent lesion. Second and third operations were done to remove the tumour. Similar HPE findings of atypical meningioma.
- Current presentation of worsening headache for 2 weeks.
MRI findings:
- worsening of previously seen intra-axial changes at right parietal lobe adjacent to previously seen extra-axial lesion
- The abnormal lesion is hypointense on T1, isointense on T2 with irregular peripheral enhancement post contrast.
- Significant perilesional vasogenic oedema is seen.
Diagnosis: Meningioma recurrence with radiation necrosis
Discussion:
- Radiation necrosis refers to necrotic degradation of brain tissue following regional radioation for treatment of intracranial pathology or head and neck tumours
- It can appears several months to several years after radiation therapy
- MRI shows abnormal signal in the white matter which is high signal on T2WI, single or multiple, enhancement can be seen as soap-bubble or ‘swiss-cheese’ pattern
- MRS shows low choline, creatine and NAA
- MR perfusion does not show increaed rCBV in radiation necrosis, a feature helpful to differentiate with residual lesion or tumour recurrence.
