Progressive visual loss following rupture of an intracranial dermoid cyst.

A 51-year-old man with several months of headache and progressive visual decline was found to have bilateral optic disc pallor with significant impairment of visual acuity. Despite a thorough ophthalmologic evaluation, the cause of visual loss could not be elucidated. MRI of the brain revealed a lesion in the left anterior Sylvian fissure as well as disseminated foci of subarachnoid fat consistent with a diagnosis of a ruptured dermoid cyst. The decision for open surgical resection was chosen to minimize the risk of cyst re-rupture and further visual or neurologic decline. The diagnosis of dermoid cyst was confirmed at the time of surgery. Vasospasm-induced ischemia of the optic nerves, optic chiasm or bilateral optic tracts secondary to the inflammatory reaction following cyst rupture is the most likely mechanism of visual loss in this patient. To the authors' knowledge, this report represents the first reported case of visual loss secondary to rupture of an intracranial dermoid cyst not related to mass effect of the tumor on the optic apparatus, visual pathways or visual cortex.