A 45-year-old woman presents with progressive headache and diplopia. MRI brain shows a well-defined extra-axial mass in the left parasellar region. The mass is isointense to grey matter on T1 and T2, shows homogeneous avid enhancement with gadolinium, and a dural tail is noted extending from its margins. There is no surrounding oedema. What is the most likely diagnosis?
- A Pituitary macroadenoma
- B Trigeminal schwannoma
- C Meningioma ✓
- D Cavernous sinus thrombosis
Explanation
Meningioma is the most common extra-axial intracranial tumour in adults and arises from arachnoid cap cells. The classic MRI features are: extra-axial location, isointensity to grey matter on T1 and T2, intense homogeneous enhancement, and a dural tail representing reactive dural thickening adjacent to the tumour. The dural tail is not pathognomonic but is seen in 60-70% of meningiomas and helps confirm the extra-axial nature. Pituitary macroadenomas arise from the sella and typically show a waist at the diaphragma sellae. Schwannomas arise from the cisternal nerve segment and may be hypointense on T1 with heterogeneous enhancement.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.