Meningioma.Care & specialists in Ireland

Most meningiomas (about 80%) are WHO grade 1 and are considered benign — they grow slowly, do not invade brain tissue, and rarely spread elsewhere in the body. About 18-20% are grade 2 (atypical) with a higher recurrence rate, and 1-3% are grade 3 (anaplastic / malignant) which behave like cancer. So meningioma can be benign or malignant depending on the grade assigned by pathology.

Common first symptoms include a gradually worsening headache, new-onset adult seizure, slowly progressive weakness on one side of the body, vision changes, hearing loss, or a personality and memory change. Many meningiomas cause no symptoms and are found incidentally on an MRI done for another reason. Any new focal neurological symptom in an adult warrants brain imaging.

Contrast-enhanced MRI of the brain or spine is the definitive test. A meningioma shows as a dural-based extra-axial mass with intense homogeneous gadolinium enhancement and often a dural tail. CT shows calcification and adjacent bone changes. Final WHO grade is confirmed by pathology after surgery, including TERT and CDKN2A/B molecular testing.

No. Small asymptomatic meningiomas found incidentally are often managed with serial MRI surveillance rather than surgery. About 60% of incidental grade 1 tumors show no growth over 5 years. Surgery is considered when the tumor causes symptoms, grows on imaging, or is in a location where future growth would be dangerous to operate on.

The Simpson grading system, introduced by Donald Simpson in 1957, describes how completely a meningioma has been surgically removed. Grade I removes the tumor, its dural attachment, and any involved bone; grade II coagulates the dural attachment; grade III leaves dura behind; grade IV is partial; grade V is decompression only. Recurrence rises from about 9% at Simpson I to 40% at Simpson IV at 10 years.

WHO grade 1 is benign, slow-growing, and rarely invades brain tissue. Grade 2 (atypical) has more mitoses, brain invasion, or specific histologic features and recurs more often. Grade 3 (anaplastic) is malignant, with high mitotic counts, TERT promoter mutation, or CDKN2A/B deletion; survival is shorter and recurrence is high. The 2021 WHO classification now incorporates molecular markers into grading.

For small (under about 3 cm) meningiomas away from the optic nerves and brainstem, stereotactic radiosurgery (Gamma Knife or LINAC SRS) is a durable alternative to craniotomy with 10-year tumor control of 87-95% for grade 1 disease. Larger tumors causing mass effect, or those near critical structures, are still managed primarily by surgery, with radiosurgery used for residual or recurrent disease.

Most patients are discharged 3-5 days after craniotomy, return to light daily activities within 2-4 weeks, and to full work within 6-12 weeks depending on tumor location and any neurological deficit. Fatigue gradually improves over 3-6 months. Pre-operative deficits often partially recover; deficits still present at 6 months are usually permanent.

Women are 2-3 times more likely than men to develop grade 1 meningioma. Meningiomas express progesterone receptors in 60-90% of cases and tumors can enlarge during pregnancy and the luteal phase. The female predominance narrows for grade 2 disease and reverses for grade 3, which is slightly more common in men.

Most meningiomas arise from acquired (sporadic) mutations and are not inherited. However, neurofibromatosis type 2 (NF2), schwannomatosis, Gorlin syndrome, Cowden syndrome, and Li-Fraumeni syndrome all increase meningioma risk and are inherited. Multiple meningiomas, diagnosis before age 30, or a strong family history of CNS tumors should prompt genetic referral.

Yes. 10-year recurrence after gross-total resection is approximately 20% for grade 1, 40-50% for grade 2, and over 70% for grade 3 meningioma. Subtotal resection recurs more often. Adjuvant radiotherapy or radiosurgery substantially reduces recurrence for residual disease and for higher-grade tumors. Surveillance MRI continues for many years after surgery.

The dural tail is a thickened, enhancing strip of dura that extends from the edge of a meningioma along the meninges. It is seen on contrast-enhanced MRI in roughly 60-70% of meningiomas and is highly suggestive of the diagnosis, though not entirely specific — dural metastases and granulomatous disease can mimic it.

Meningiomas can enlarge during pregnancy because of progesterone receptor signaling and increased blood volume. Tumors that were asymptomatic may become symptomatic, particularly in the second and third trimesters. Symptoms often regress after delivery. Women with a known meningioma planning pregnancy should have baseline MRI and obstetric-neurosurgical co-management.

Five-year relative survival is approximately 96% for grade 1, 65% for grade 2, and 35% for grade 3 meningioma (CBTRUS 2024 data). Most grade 1 patients achieve normal life expectancy with appropriate treatment. Grade 3 anaplastic meningioma carries a median overall survival of 2-3 years.

Meningiomas arise from somatic mutations in arachnoid cap cells of the meninges, most commonly NF2 loss in convexity tumors and TRAF7, KLF4, AKT1, or SMO mutations in skull-base tumors. Known risk factors include prior cranial radiation, neurofibromatosis type 2, female hormonal exposure, and long-term high-dose cyproterone acetate. Most cases have no identifiable single cause.

Long-term high-dose cyproterone acetate (cumulative dose above 60 g) is associated with a 7-fold increased risk of meningioma, particularly multiple skull-base tumors, in French nationwide nested case-control data (Weill 2021, BMJ). European labeling now restricts duration of high-dose use. Risk regresses after stopping the drug.

Spinal meningiomas account for about 10% of all meningiomas and 25% of all spinal cord tumors. They occur predominantly in middle-aged women, sit most often in the thoracic spine, and present with progressive limb weakness, sensory loss, or gait disturbance. Surgical resection achieves long-term cure in over 85% of cases, with 10-year recurrence below 10%.

Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder caused by germline NF2 gene mutation. Patients develop bilateral vestibular schwannomas, multiple meningiomas, and spinal tumors, often presenting in the teens or twenties. Any patient under 40 with multiple meningiomas should be evaluated for NF2 by clinical genetics.

For incidental untreated meningiomas, EANO guidance is MRI at 6 months, then annually for 5 years, then every 2 years if stable. After surgery, MRI at 3 months, then yearly for grade 1 disease, and more often for grade 2 and 3. Lifelong surveillance is typical because recurrence can occur after many years.

Yes. New-onset seizures are the presenting feature in roughly 25-30% of supratentorial meningiomas. After surgery, 15-25% of patients have post-operative seizures requiring anticonvulsant therapy. Levetiracetam is the preferred first-line agent because it has minimal interactions with steroids and chemotherapy.

Standard cytotoxic chemotherapy has limited activity in meningioma. Bevacizumab, somatostatin analogs such as octreotide, and targeted therapies including SMO, AKT1, and FAK inhibitors are used selectively for recurrent grade 2 and 3 disease after surgery and radiotherapy. Most patients with refractory meningioma are best served by clinical trial enrollment.

Meningioma arises from the meninges outside the brain and is extra-axial; most are benign and curable by surgery. Glioblastoma arises from glial cells within brain tissue and is intra-axial, infiltrative, and aggressive, with median survival of 12-18 months despite surgery, radiotherapy, and chemotherapy. MRI distinguishes the two with near certainty.