Subarachnoid Hemorrhage Associated with Intratumoral Aneurysm Rupture within a Posterior Fossa Hemangioblastoma: The Importance of Continued Surveillance for Cerebral Vasospasm

Successful treatment with urgent revascularization and parent artery occlusion for a ruptured intratumoral aneurysm following prior meningioma surgery: illustrative case

BACKGROUND

An intratumoral aneurysm encased within the associated intracranial tumor is rare, and hemorrhage caused by its rupture is even more rare. While urgent and adequate surgical treatment is important, the treatment can be difficult given the limited understanding of this rare condition.

OBSERVATIONS

A 69-year-old man who had undergone meningioma surgery 30 years prior presented with a disturbance in consciousness. Magnetic resonance imaging revealed massive intracerebral and subarachnoid hemorrhage. A round, partially calcified mass, which was diagnosed as recurrent meningioma, was also observed. Subsequent cerebral angiography revealed that the source of the hemorrhage was an intratumoral aneurysm in the dorsal internal carotid artery (ICA) encased within the recurrent meningioma. Urgent surgical ICA trapping and high-flow graft bypass were conducted. The postoperative course was uneventful, and he was referred to another hospital for rehabilitation.

LESSONS

This is the first case report of a ruptured intratumoral aneurysm being treated with urgent combined revascularization and parent artery trapping surgery. This surgical approach may be a feasible treatment option for such a challenging condition. Additionally, this case highlights the importance of diligent long-term follow-up after skull-base surgery, as minor intraoperative vascular wall injury may trigger the development and rupture of an intracerebral aneurysm.

Solid vs. cystic predominance in posterior fossa hemangioblastomas: implications for cerebrovascular risks and patient outcome

BACKGROUND

Hemangioblastomas (HGBs) are highly vascular benign tumors, commonly located in the posterior fossa, and 80% of them are sporadic. Patients usually present with features of raised intracranial pressure and cerebellar symptoms. HGB can be classified as either mostly cystic or solids. Although the solid component is highly vascularized, aneurysm or hemorrhagic presentation is rarely described, having catastrophic results.

METHODS

We identified 32 consecutive patients with posterior fossa HBG who underwent surgery from 2008 through 2020 at our medical center. Tumors were classified as predominantly cystic or solid according to radiological features. Resection was defined as gross total (GTR) or subtotal (STR).

RESULTS

During the study period, 32 posterior fossa HGBs were resected. There were 26 cerebellar lesions and 4 medullar lesions, and in 2 patients, both structures were affected. Predominant cystic tumors were seen in 15 patients and solids in 17. Preoperative digital subtraction angiography (DSA) was performed in 8 patients with solid tumors, and 4 showed tumor-related aneurysms. Embolization of the tumors was performed in 6 patients, including the four tumor-related aneurysms. GTR was achieved in 29 tumors (91%), and subtotal resection in 3 (9%). Three patients had postoperative lower cranial nerve palsy. Functional status was stable in 5 patients (16%), improved in 24 (75%), and 3 patients (9%) deteriorated. One patient died 2 months after the surgery. Two tumors recurred and underwent a second surgery achieving GTR. The mean follow-up was 42.7 months (SD ± 51.0 months).

CONCLUSIONS

Predominant cystic HGB is usually easily treated as the surgery is straightforward. Those with a solid predominance present a more complex challenge sharing features similar to arteriovenous malformations. Given the important vascular association of solid predominance HGB with these added risk factors, the preoperative assessment should include DSA, as in arteriovenous malformations, and endovascular intervention should be considered before surgery.