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