Brain tumors in adults
In adults, brain metastases (lung, breast, kidney, melanoma) are the most common intracranial tumors, meningioma is the most common primary tumor, and glioblastoma multiforme is the most aggressive primary glioma. Management combines resection when feasible, radiation, and chemotherapy (temozolomide for glioblastoma, methotrexate-based regimens for CNS lymphoma) with corticosteroids and antiepileptics for symptom control.
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What this article covers
- Overview
Scope of this article: the major adult intracranial tumor categories, brain metastases, meningioma, glioblastoma multiforme and other gliomas, and primary CNS lymphoma (PCNSL).
- Epidemiology
Metastatic sources, most likely: lung, breast, and kidney cancers and melanoma; metastases can be solitary but are more often multiple.
- Risk factors
Prior therapeutic radiation to the head: the only consistent risk factor identified for developing gliomas, including glioblastoma multiforme.
- Pathophysiology
Meningioma: arises from arachnoid (meningothelial) cap cells, dural-based, growing as a benign, slow, extra-axial mass that displaces rather than infiltrates brain, which is why many are followed clinically rather than resected.
- Clinical features
Meningioma: often asymptomatic and found incidentally; when symptomatic, presents with focal deficits from compression of adjacent brain, drug-resistant seizures, severe headache, or peritumoral edema.
- Differential diagnosis
Meningioma versus dural metastasis: meningioma shows a smooth, rounded shape with homogeneous "lightbulb" enhancement and a dural "tail"; a dural metastasis is more irregular and occurs with a known aggressive primary.
- Diagnosis
Diagnosis is established by imaging characterization, with tissue pathology (resection or biopsy) required for definitive tumor type and grade except when the imaging pattern is sufficiently…
- Management
First, stabilize if there is mass effect, edema, or herniation risk: head of bed to 30 degrees, then: Dexamethasone 10 mg IV once, then 4 mg IV or PO every 6 hours for peritumoral vasogenic edema.
- Complications
Herniation: the most immediately life-threatening complication of tumor growth, hemorrhage, or peritumoral edema; see brain herniation syndromes.
- Prognosis
Meningioma: excellent overall, particularly for tumors followed clinically or completely resected; malignant transformation is uncommon.
- Prevention
No established primary prevention exists for sporadic adult brain tumors, since the only consistent risk factor, prior therapeutic radiation, is usually medically necessary for a separate condition.
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