Sporadic Meningioma

A sporadic meningioma is a meningioma that arises without a known hereditary or familial predisposition. These tumors develop de novo, typically as isolated lesions, and account for the majority of meningioma cases in the general population.

A meningioma is a primary central nervous system tumor that arises from the arachnoid cap cells of the meninges. When it occurs outside the context of genetic syndromes such as neurofibromatosis type 2 (NF2), it is classified as sporadic.

• Represents ~80–90% of all meningiomas.
• More common in women.
• Typically occurs in middle-aged to older adults.
• Risk factors may include age, ionizing radiation, and hormonal influences.

• NF2 gene mutation or 22q deletion: common in sporadic grade I and II meningiomas.
• Non-NF2 mutations: TRAF7, KLF4, AKT1, SMO, and PIK3CA — associated with specific histological subtypes and locations.
• Typically lacks germline mutations found in familial syndromes.

• Often asymptomatic, discovered incidentally.
• Symptoms depend on tumor size and location:
  • Headache
  • Seizures
  • Focal neurological deficits
  • Visual changes, depending on location

• Neuroimaging: MRI with contrast (gold standard)
• Histopathological confirmation after surgical resection
• Molecular profiling increasingly used for classification and prognosis

• Observation for small, asymptomatic tumors
• Surgical resection (Simpson grade I-II ideal)
• Radiotherapy (e.g., stereotactic radiosurgery) for residual or inoperable cases
• Ongoing trials for targeted therapies in selected molecular subtypes

• Familial or syndromic meningiomas (e.g., NF2-related)
• Hemangiopericytoma / Solitary fibrous tumor
• Dural metastasis

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