Meningioma is a tumor that arises from the meninges, the protective layers of tissue that surround the brain and spinal cord. Most meningiomas grow slowly and are classified as benign (WHO grade 1), although a smaller proportion are atypical (WHO grade 2) or anaplastic (WHO grade 3) and behave more aggressively. Several recognized subtypes have been described based on histological appearance and anatomical location, including meningothelial, transitional, microcystic, angiomatous, clear cell, papillary, rhabdoid, skull base, intraspinal, and supratentorial forms, as well as familial presentations. The clinical course depends on tumor location, grade, size, and resectability rather than on a single uniform pattern. Population-level prevalence figures vary across registries and are not summarized as a single number in the data assembled for this report.

Symptoms of meningioma depend strongly on tumor location, size, and growth rate, and many small tumors are discovered incidentally on imaging performed for unrelated reasons. When symptoms do occur, they reflect pressure on adjacent brain, cranial nerve, or spinal cord structures. Commonly observed manifestations include headaches that may worsen over time, seizures, focal weakness or sensory changes, gait or balance difficulties, cognitive or personality changes, and visual disturbances such as decreased vision, double vision, or visual field loss. Tumors arising near the skull base may affect cranial nerve function and produce hearing changes, facial numbness, or swallowing difficulty. Intraspinal meningiomas may present with back pain, limb weakness, sensory deficits, or changes in bowel or bladder function. Higher-grade meningiomas can grow more rapidly and produce symptoms over a shorter time course. Not all individuals experience all features, and severity varies considerably.

Most meningiomas occur sporadically and arise from changes acquired in the meningothelial cells lining the meninges over the course of an individual's life rather than from inherited mutations. The biological mechanisms include genomic alterations in tumor cells that affect cell growth and survival, but the specific genes involved are not detailed in the data assembled for this report. Established risk factors include prior therapeutic radiation exposure to the head, increasing age, and a higher incidence in women, particularly for grade 1 tumors. A smaller subset of meningiomas occurs in the setting of recognized predisposition syndromes or in families with multiple affected relatives, and a familial form is described as a distinct subtype. Because most cases are not inherited, recurrence risk to relatives in sporadic cases is generally low. Individuals or families with multiple meningiomas, very early onset, or other suggestive findings may be referred for genetic counseling and consideration of testing.

Diagnosis of meningioma typically begins with clinical evaluation of symptoms followed by neuroimaging. Magnetic resonance imaging of the brain or spine with contrast is the primary modality and characteristically shows an extra-axial, dural-based mass with uniform contrast enhancement and, in many cases, a dural tail. Computed tomography may demonstrate calcification or adjacent bony changes. When tissue is obtained through surgical resection or biopsy, histopathological examination establishes the histological subtype and assigns the WHO grade, which informs prognosis and management planning. Molecular and immunohistochemical studies may be incorporated to refine classification in selected cases. Imaging surveillance without biopsy may be appropriate for small, asymptomatic tumors with typical features. Symptoms of meningioma can overlap with those of other intracranial or spinal lesions, including other primary central nervous system tumors, metastases, and non-neoplastic conditions, so neuroimaging and, where indicated, pathological evaluation are required to confirm the diagnosis and distinguish it from conditions with similar presentations.

Treatment of meningioma is individualized and depends on tumor grade, location, size, growth on serial imaging, symptoms, and the patient's overall health and preferences. Care is typically coordinated by a multidisciplinary team that may include neurosurgery, radiation oncology, neuro-oncology, neurology, ophthalmology, and rehabilitation specialists. Management strategies include active surveillance with serial imaging for small, asymptomatic tumors; surgical resection, which can be curative for many grade 1 tumors when complete removal is feasible; and radiation therapy, including stereotactic radiosurgery or fractionated external beam radiotherapy, used either as primary treatment when surgery is not possible or as an adjuvant therapy for higher-grade or incompletely resected tumors. Systemic therapy options for meningiomas that progress after surgery and radiation are limited and remain an active area of clinical investigation. Supportive care addresses symptoms such as seizures, headache, and neurological deficits and includes rehabilitation services where appropriate. There are no specifically approved treatments for meningioma listed in the data assembled for this report; management is guided by surgical and radiation principles. Patients should discuss treatment options with their healthcare team to determine which therapies may be appropriate for their specific situation.

The outlook for individuals with meningioma varies considerably and depends most strongly on tumor grade, anatomical location, extent of surgical resection, and patient age and overall health. Many grade 1 meningiomas that are completely resected have favorable long-term outcomes, and small, asymptomatic tumors observed on imaging may remain stable for years. Grade 2 (atypical) and grade 3 (anaplastic) meningiomas are associated with higher rates of local recurrence and a more aggressive clinical course, and they often require additional therapy beyond surgery. Tumor location can also affect prognosis, since meningiomas at the skull base or in deep midline regions may be technically difficult to resect completely. Long-term follow-up with serial imaging is part of standard care for many patients, given that recurrence can occur years after initial treatment. With current standards of multidisciplinary care, including modern microsurgical and radiation techniques, many individuals achieve durable disease control and preserved quality of life.

Research on meningioma is active, with numerous clinical trials currently recruiting or in progress. Investigational areas include radiation strategies, targeted therapies for higher-grade and recurrent disease, radiopharmaceutical approaches, and studies focused on cognitive and quality-of-life outcomes after treatment. Notable ongoing studies include a Phase 3 trial led by NRG Oncology evaluating observation versus radiation therapy after complete surgical resection of newly diagnosed grade 2 meningioma, a Phase 2 trial sponsored by RTOG Foundation comparing a radiopharmaceutical approach with standard of care for recurrent meningioma, and a Phase 2 study at Mayo Clinic of a peptide receptor radionuclide therapy in inoperable, progressive meningioma after external beam radiation therapy. Other studies are evaluating targeted agents and novel approaches in progressive or recurrent disease. Individuals interested in clinical trials can search ClinicalTrials.gov or consult their care team about eligibility.