Intracranial hemorrhages associated with meningiomas: Own experience and literature review.

Intracranial hemorrhage associated with meningioma is rare. Relatively, few such cases are described in the source literature, and it is estimated that intracranial meningiomas presenting with hemorrhage account for about one percent of all meningiomas. Hemorrhage can occur in both meningioma tissue and on the tumor surface. It can lead to intracerebral, subdural and subarachnoid hematoma. This can in turn cause high intracranial pressure with rapid neurological deterioration. Urgent neurosurgical intervention is often necessary. In our department, three patients with meningioma-related hemorrhage were treated surgically from 2006 to 2020. One patient was operated on as an emergency, due to the patient's poor neurological condition, while the two others underwent surgery following supplementary diagnosis several days following their admission. The outcomes of the three patients were good. The three meningiomas associated with hemorrhage described in the present manuscript constitute 2.2% of all 136 meningiomas treated surgically from 2006 to 2020 at our department. All three hemorrhages described in this study were associated with WHO I convexity meningiomas. Similar data can be found in some sources also describing meningioma WHO I-related hemorrhages; nevertheless, other literature references indicate a higher risk of bleeding into meningiomas of a higher degree of malignancy. The hemorrhage mechanism remains unclear; however, the proposed mechanism is rupture of defective intratumoral blood vessels and stretching of the superficial veins including bridge veins by the growing tumor, leading to their rupture. Our observations regarding the incidence of meningioma hemorrhage and tumor location are consistent with the source literature data.