Jugular Tubercle Meningioma with Hemorrhagic Conversion Mimicking a Ruptured Thrombosed Giant Vertebrobasilar Aneurysm

Background: Hemorrhagic meningiomas, although relatively uncommon, represent a distinct clinical entity. In some cases, these meningiomas can closely mimic a thrombosed aneurysm. We present a case of a jugular tubercle meningioma whose radiographic and clinical picture initially suggested a ruptured, thrombosed vertebrobasilar aneurysm. This case serves to highlight several key differences between these 2 pathologies that can assist in diagnosis. Case Description: A 54-year-old woman presented to an outside hospital with a severe, sudden onset headache along with new-onset horizontal diplopia. On examination, she was noted to have a left sixth nerve palsy. A computerized tomography scan was performed and demonstrated a mass in the region of the left jugular foramen. A subsequent lumbar puncture was suggestive of subarachnoid hemorrhage. Frozen section was suggestive of meningioma and our patient underwent a successful gross total resection with no permanent neurological sequelae. Conclusions: Hemorrhagic meningiomas can have a clinical and radiologic picture that closely resembles a ruptured, thrombosed cerebral aneurysm. Based on our single case, we suggest several important diagnostic differentiators between these 2 entities. We found the hemorrhagic meningioma to exhibit eggshell-like rim calcification, thick, irregular peripheral enhancement, and a central cystic component. This can be contrasted to the classic appearance of a thrombosed aneurysm with mixed T₁-, T₂-weighted signal intensity, and occasional regular, thin peripheral enhancement.