Intracranial angiomatous meningiomas: A 15-year, multicenter study.

Background: Angiomatous meningiomas (AMs) represent a rare subtype of meningiomas in which the vascular component prevail. They represent less than 1% of all intracranial tumors and approximately 2.1% of all meningeal tumors (Hasselblatt et al., 2004). The purpose of this study was to determine the clinical characteristics, radiological features and prognosis of AMs based on a Tunisian multicenter experience in the management of 58 successive cases of intracranial AMs. To the best of our knowledge, this is the largest series reported to date.

Methods: We retrospectively reviewed 58 patients of AM treated in the departments of Neurosurgery of The Tunisian National Institute of Neurology, Sahloul University Hospital and Fattouma Bourguiba University Hospital from January 2001 to December 2015. Clinical characteristics, radiographic features and treatment modality, in the form of radical surgery, were noted. Statistical analysis was done with regards to recurrence free survival (RFS) and overall survival (OS) using Kaplan-Meier survival analysis.

Results: The median age of the patients on admission was 53.0 years (8-78). Twenty-two patients were males and thirty-six were females. The median duration of symptoms prior to presentation was six months. Signs of increased intracranial pressure were the most common presenting symptom followed by seizures, motor weakness and cranial nerves paresis. Cystic changes were observed in 50% of cases, moderate to severe peritumoral edema in 81% of cases and multiple signal voids suggestive of blood vessels in 86.2% of cases. Forty-two patients underwent Simpson I excision (72.4%) while fourteen had Simpson II excision (24.1%). A Simpson III resection was realized in two patients (3.5%). The surgical resection was hemorrhagic in 63.8% of cases and in 13.8% of cases, several blood transfusions were necessary to maintain hemodynamic stability. No adjunctive treatment was administered. Six out of the fifty-six patients of the Simpson I/II groups recurred while one of the two patients with Simpson III resection had tumor regrowth. Median duration of RFS was 103 months. Second surgery was realized in all cases with no subsequent recurrence. The extent of tumor resection and the location were found to correlate with the risk of developing recurrences (P=0.001).

Conclusions: AMs represent a rare subtype of meningioma characterized by variable cystic components, large peritumoral edema and multiple areas of vascular signal voids. The mainstay of the treatment is gross total resection, ideally following a preoperative embolization. The fate of the tumor remnant after incomplete tumor resection still needs to be evaluated and we do not recommend the systematic use of post-operative adjuvant RT in all cases. As local recurrence can develop many years after initial treatment, Long-term follow-up is mandatory.