Occult falcine meningioma unmasked following nearly complete hemorrhagic transformation with resultant spontaneous acute interhemispheric subdural hematoma.

Sudden-onset monoplegia with features of vomiting and headache usually signals an intracranial cerebrovascular event. We describe a 62-year-old man in whom this presentation was the result of the rare occurrence of an almost complete hemorrhagic transformation of a falcine meningioma with resultant acute interhemispheric subdural hematoma, and discuss the risk factors and possible mechanisms that may lead to such an event. The need for careful examination of the available radiology and aggressive tumor removal is stressed.