Abstract

Meningiomas are highly cellular tumour with or without calcifications and hence hyperdense on plain CT scans. Areas of hypodensity are seen in cystic areas within meningioma and necrosis. Uniformly hypodense meningiomas are extremely rare and we could find only 5 case reports in literature. We present a case of 66 year old female with history of trauma due to fall 4 months back and one episode of seizure 15 days back. CT brain showed uniformly hypodense extra-axial lesion in right frontal region with average Hounsfield unit of 25.6. We first thought of chronic extradural hematoma in view of past history of trauma. Closer observation warranted further imaging, which showed enhancement of the lesion on contrast CT scan suggesting meningioma or bone tumour or cortical or extradural metastases. MRI brain showed T1 hypointense, T2 hyperintense lesion not suppressed on FLAIR, with heterogeneous enhancement post- contrast with dural tail sign suggesting first differential diagnosis of meningioma. Surgical SIMPSON grade I excision was performed and pathology was microcystic variant of meningioma which is the rarest subtype of meningioma. This case is presented due to its unusual plain CT finding and its rarity. Even though there is history of trauma, looking beyond the box helped us in reaching to a reasonable preoperative radiological diagnosis

Key words: meningioma microcytic hypodense