MRI brain of a 40-year-old with seizures shows a well-defined lesion in the temporal lobe that is T1 hypointense, T2/FLAIR hyperintense, with no surrounding oedema, no mass effect, no post-gadolinium enhancement, and restricted diffusion is absent. The apparent diffusion coefficient (ADC) value is high. The most likely diagnosis is:
- A Glioblastoma multiforme
- B Cerebral metastasis
- C Low-grade glioma (WHO grade 2) ✓
- D Acute ischaemic stroke
Correct answer: C. Low-grade glioma (WHO grade 2)
Explanation
Low-grade gliomas (WHO grade 2 astrocytoma, oligodendroglioma) are characteristically T2/FLAIR hyperintense without enhancement, minimal mass effect, no surrounding oedema, and have elevated ADC (high diffusivity) reflecting their loose cellular architecture. Glioblastoma shows ring enhancement, necrosis, and oedema. Metastases have surrounding vasogenic oedema and enhancement. Acute stroke shows restricted diffusion (low ADC).
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.