Bilateral aneurysms, one of which is embedded in a meningioma: a rare case report and literature review.

Background: Although the coexistence of primary brain neoplasms with intracranial aneurysms is rare, this phenomenon has become more recognized. Meningioma is the most frequently occurring type of tumor associated with an aneurysm. However, meningiomas encasing aneurysms are extremely rare, posing a diagnostic and therapeutic challenge to healthcare providers.

Case description: We report a case of a 46-year-old female patient admitted to our hospital with headache and dizziness for ten years. Enhanced magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) indicated a mass in the right sphenoid ridge, surrounding a posterior communicating artery aneurysm of the right internal carotid artery. Digital subtraction angiography (DSA) revealed left ophthalmic segment aneurysm and right posterior communicating artery aneurysm. We first clipped the aneurysm and then removed intracranial tumor during the same operation. The postoperative pathological diagnosis of tumor was meningioma (World Health Organization grade I). The patient's postoperative course was uneventful, with only a mild reduction in lateral vision of both eyes.

Conclusions: We reported a rare case in which an intracranial aneurysm was encased in a meningioma and could be safely treated during the same operation. Notably, embolizing or clipping aneurysm first and then removing intracranial tumor appears to enhance the safety of patients. This is the best treatment option if the aneurysm and meningioma can be treated concurrently in the hybrid operating room. Additionally, it may be necessary to carefully evaluate preoperative MRA or computed tomography angiography (CTA), and it is critical to confirm the existence of any vascular lesions in patients with brain tumors using MRA or CTA.