Optic Nerve Cavernous Haemangioma as a Rare Cause of Retro-Orbital Pain mimicking Intracranial Aneurysm

Cavernous haemangiomas of the optic nerve, optic chiasm or optic tract are rare. Usually they present with acute onset of symptoms such as acute decline of visual acuity, headaches, nausea or even decline of the level of consciousness which suggests haemorrhage in or even out of the lesion. Otherwise, they have an insidious clinical pattern with subacute or chronic visual disturbance, diplopia and retro- orbital pain. We present a case of a 42-year-old male patient with pain behind the left bulbus and progressive unilateral visual loss and hemianopsia who was admitted to our clinic with the possible diagnosis of an aneurysm of the left internal carotid artery. The diagnostic work up included thin layer MRI, digital angiography and CT wherein the assumed diagnosis was cavernous haemangioma or tumor of the optic nerve. Total excision of the lesion was achieved via a left frontolateral approach resulting in marked improvement of the visual acuity and the visual field. The histological evaluation confirmed the diagnosis of a cavernous haemangioma.