Acute subdural hematoma caused by hemorrhagic falx meningioma: A case report and review of the literature.

We herein report a case of acute subdural hematoma caused by hemorrhagic falx meningioma. The patient was a 64-year-old woman with no significant medical history or prior history of trauma. She experienced a sudden onset of headache and weakness in her extremities. Computed tomography (CT) scan and magnetic resonance imaging (MRI) showed a mass lesion with intratumoral hemorrhage or faint calcification along the left side of the fronto-parietal cerebral falx. There was also a linear lesion at the left side of the falx, suggesting acute subdural hematoma. MRI was performed again on the eleventh day. On precontrast T1-weighted images, intratumoral hemorrhage and widespread left subdural hematoma were shown as high intensity. On postcontrast T1-weighted images, the tumor showed heterogeneous enhancement with a dural tail sign on the falx, indicative of a falx meningioma. She underwent surgical resection, and the histological subtype was transitional meningioma. Nine cases of hemorrhagic falx meningioma associated with acute subdural hematoma have been reported. If not limited to the site of occurrence, there have been 59 reported cases overall. In our investigation, the incidence of hemorrhage is higher in the convexity and lower in the skull base. It is higher for fibrous, angiomatous, and metaplastic subtypes and lower for meningothelial subtype. The location and histological subtype might be risk factors for meningioma associated with subdural hematoma. Further accumulation of cases will be necessary to establish the cause of bleeding.