Brain tumor classification and management

🧠 Tumor Terrors: Definition & Classification

• Primary: Arise from CNS tissue. Location is key: supratentorial in adults (70%), infratentorial in children (70%).
• Metastatic: Spread from systemic cancer; the most common intracranial tumor in adults. Characteristically multiple, well-circumscribed lesions at the gray-white junction.
• Classification: Based on cell of origin and histology (WHO grades I-IV; higher grade indicates greater malignancy).

⭐ In adults, metastatic tumors are the most common intracranial tumors. Among primary tumors, glioblastoma is the most common and aggressive, followed by meningioma.

📌 Metastases: "Lots of Bad Stuff Kills" (Lung, Breast, Skin [Melanoma], Kidney).

🧠 Brain Under Siege: Clinical Manifestations

Symptoms arise from generalized increased intracranial pressure (ICP) and focal neurologic deficits due to local compression or destruction.

• Generalized Symptoms (↑ ICP):

  • Headache: Classically worse in the morning, exacerbated by coughing/bending.
  • Nausea/Vomiting: Often projectile, may occur without preceding nausea.
  • Papilledema: Optic disc swelling on fundoscopy, a sign of chronic ↑ ICP.
  • Mental Status Changes: Lethargy, drowsiness, cognitive decline.
  • ⚠️ Cushing's Triad: Late, ominous sign of brainstem compression: hypertension, bradycardia, irregular respirations.

• Focal Deficits (Location-Dependent):

  • Seizures: A new-onset seizure in an adult is a major red flag.
  • Motor/Sensory Loss: Contralateral weakness or numbness.
  • Aphasia: Language dysfunction (e.g., Broca's, Wernicke's).
  • Visual Field Defects: e.g., Bitemporal hemianopsia with pituitary tumors.

⭐ A new-onset seizure in an adult is considered a brain tumor until proven otherwise.

![Diagram showing types of brain herniation and associated clinical signs]

🕵️ Diagnosis - Spotting the Shadow

• Initial Imaging (ER/Acute): Non-contrast CT to rule out hemorrhage.
• Gold Standard: MRI with gadolinium contrast is the most accurate test.
  • T1 + Gadolinium: Highlights breakdown of the blood-brain barrier (enhancement).
  • T2/FLAIR: Shows surrounding vasogenic edema.
• Definitive Diagnosis: Biopsy (stereotactic or open) for histopathology.
  • ⚠️ Lumbar Puncture: Contraindicated with signs of ↑ICP due to herniation risk.

⭐ Ring-enhancing lesions on MRI are classic. 📌 Mnemonic: MAGIC DR L (Metastasis, Abscess, Glioblastoma, Infarct, Contusion, Demyelinating disease, Radiation necrosis, Lymphoma).

🧠 Management - The Neuro-Playbook

• Initial Stabilization:

  • Manage ↑ICP: Head elevation, hyperventilation (transient).
  • Dexamethasone for vasogenic edema.
  • Mannitol or hypertonic saline for acute herniation.
  • Antiepileptics for seizures.

• Definitive Management Flow:

⭐ Dexamethasone is first-line for vasogenic edema from tumors; it reduces ICP by stabilizing the blood-brain barrier but does not treat the tumor itself.

⚡ Biggest Takeaways

• Metastases are the most common adult brain tumors, often from Lung, Breast, and Melanoma.
• Glioblastoma is the most common primary adult tumor; a ring-enhancing "butterfly" lesion.
• Meningiomas are typically benign, arise from arachnoid cells, and show a dural tail.
• In children, tumors are usually infratentorial. Pilocytic astrocytoma is most common.
• Medulloblastoma is a malignant childhood cerebellar tumor causing hydrocephalus.
• Manage vasogenic edema and mass effect with corticosteroids.