Unilateral optic disc swelling: an atypical presentation for a large frontal meningioma

Intracranial space occupying lesions pose a frequent diagnostic dilemma from history and clinical signs alone. They remain an important differential in those presenting with neurological or ophthalmological symptoms. We present a case of a large frontal meningioma in a 47-year-old man presenting with unilateral optic disc swelling and contralateral visual field disturbance alongside a subacute history of severe, intermittent, non-orthostatic headaches and mild behavioural disturbance. Neuroimaging demonstrated a large right sphenoid wing mass, suggestive of a meningioma with signs of raised intracranial pressure (ICP), local mass effect and parenchymal herniation. He subsequently underwent surgical intervention for debulking and biopsy, confirming the suspected diagnosis. This case highlights that whilst raised intracranial pressure classically leads to bilateral optic disc swelling, unilaterality does not exclude this. Concerns should therefore be raised with contralateral visual acuity (VA) changes. Detailed history and examination are important to assess for presence of red flags in determining need for neuroimaging.