Foramen magnum meningiomas: a systematic review and meta-analysis

Abstract

Foramen magnum meningiomas (FMMs) account for 1.8–3.2% of all meningiomas. With this systematic review and meta-analysis, our goal is to detail epidemiology, clinical features, surgical aspects, and outcomes of this rare pathology. Using PRISMA 2015 guidelines, we reviewed case series, mixed series, or retrospective observational cohorts with description of surgical technique, patient and lesion characteristics, and pre- and postoperative clinical status. A meta-analysis was performed to search for correlations between meningioma characteristics and rate of gross total resection (GTR). We considered 33 retrospective studies or case series, including 1053 patients, mostly females (53.8%), with a mean age of 52 years. The mean follow-up was of 51 months (range 0–258 months). 65.6% of meningiomas were anterior, and the mean diameter was of 29 mm, treated with different surgical approaches. Postoperatively, 17.2% suffered complications (both surgery- and non-surgery-related) and 2.5% had a recurrence. The Karnofsky performance score improved in average after surgical treatment (75 vs. 81, p < 0.001). Our meta-analysis shows significant rates of GTR in cohorts with a majority of posterior and laterally located FMM (p = 0.025) and with a mean tumor less than 25 mm (p < 0.05). FMM is a rare and challenging pathology whose treatment should be multidisciplinary, focusing on quality of life. Surgery still remains the gold standard and aim at maximal resection with neurological function preservation. Adjuvant therapies are needed in case of subtotal removal, non-grade I lesions, or recurrence. Specific risk factors for recurrence, other than Simpson grading, need further research.

The Role of Stereotactic Radiosurgery in the Management of Foramen Magnum Meningiomas—A Multicenter Analysis and Review of the Literature

“…FMMs represent a rare but considerable neuro-oncological challenge given their location with direct involvement of lower cranial nerves, the intradural segment of the vertebral arteries [ 6 , 7 ]. Surgery remains the mainstay of treatment for meningiomas including FMMs but given the considerable risk for treatment-associated morbidity and mortality, non-invasive treatment may embody a viable alternative [ 4 , 6 , 21 ]. Yet, radiotherapy and SRS for this tumor entity are infrequently applied, and only sparse data are available to sufficiently define their role in the management.…”

“…Only around 3% of all meningiomas arise at or close to the foramen magnum [ 3 ]. While surgery is the mainstay of treatment for meningiomas, foramen magnum meningiomas (FMMs) represent a considerable neurosurgical challenge given the risk for incomplete resections, surrounding anatomical structures, and potential for treatment-associated morbidity [ 4 , 5 , 6 ]. This is especially true for anterior and anterolateral FMMs, which comprise approximately 85% of such tumors.…”

“…The overall mortality in the past decades is around 6% [ 4 ]. If either complete surgical resection is not deemed feasible or the patient has a poor performance status, declines surgery, or in the case of a recurrence, stereotactic radiosurgery (SRS) may be a potential treatment alternative [ 6 , 7 ]. Given the rarity of FMMs and the sparse data available on the effectiveness and safety of this treatment modality, its role in the management of FMMs remains unclear [ 5 , 7 ].…”

Benign Extra-Osseous Lesions in Craniovertebral Junction and Approach

“…Literatürde klinik seriler genellikle 5-6 hasta ile en fazla 185 hastayı içerdiğinden (100 üzeri hasta bildiren sadece 3 merkez bildirilmiştir), yaklaşımları ve sonuç- Bu bölgeye far lateral, modifiye far lateral, extended far lateral, extrem lateral, lateral, suboksipital, transkondiler, transoral, transpetrosal gibi birçok yaklaşım bildirilmiştir (12). Her ne kadar posterior konvensiyonel yaklaşımlara karşın anterior transoral, anterolateral transservikal, extrem lateral, far lateral, ve lateral yaklaşımlar savunulmuş ve tercih edilmiş olsa da posterior yaklaşımların aşikar avantajları söz konusudur (13,14).…”

“…Opere ettiğimiz her üç olguda da herhangi bir instabilite gelişmedi. Anterior yerleşimli tümörlerde tümöre bağlı nedenlerle (tümörün boyutu, invaziv olması, extradural uzanımının olması, vertebra arter tutulumunun olması, araknoid kılıfın olmaması) morbiditeler görülebilmektedir (12). Tümör rekürrensinin önlenmesi için radikal diseksiyon bu lezyonlar için önemlidir.…”