Neural compressive symptoms appearing during steroid treatment in a patient with intracranial lipoma.

Intracranial lipoma is a rare condition, and it is usually asymptomatic. We describe a 67 year old woman who developed blurred vision, diplopia, left sided oculomotor palsy, and ipsilateral ptosis during steroid treatment for giant cell arteritis. These symptoms were considered to be associated with aggressive giant cell arteritis, and the steroid dose was raised. Surprisingly, the symptoms increased, and further examination revealed an intracranial lipoma situated in the Meckel's cave. During tapering of the steroids her symptoms gradually improved. This is the first report demonstrating that steroids may induce hypertrophy of the fat tissue in the intracranial lipoma, causing compression of the cranial nerves passing through the cavernous sinus thereby mimicking the ocular symptoms sometimes associated with aggressive giant cell arteritis.