Spontaneous disappearance of a middle fossa arachnoid cyst associated with subdural hematoma

Abstract

The case of a 7-year-old boy with a middle fossa arachnoid cyst that spontaneously disappeared is presented. Computed tomography (CT) scan revealed an arachnoid cyst in the right middle fossa with a thin subdural hematoma on the same side. As the subdural hematoma spontaneously resolved, the cyst became smaller and finally disappeared without surgical intervention after 18 months on the follow-up CT scans. Possible mechanisms of the spontaneous disappearance of an arachnoid cyst are discussed.