Brain Tumors

General Presentation: 

• Secondary brain tumors; metastasis: Lung, breast, melanoma, renal cell, colorectal
• Mass effect: mainly by slow-growing tumors like meningioma
• Local invasion: mainly by aggressive primary tumors
• Headache: on awakening (hyperventilating during sleep -> CO2 accumulates -> vasodilation)
• Seizure: should be a cortical lesion (supratentorial)

 

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Astrocytoma: 

1. Pilocytic astrocytoma: Grade 1 astrocytoma

• In children & young adults
• Most commonly in cerebellum + diencephalon (optic chiasm, hypothalamus)
• CT\MRI: cystic lesion + enhanced mural nodule
• Treatment -> surgery, good outcome

 

2. Low grade glioma: Grade 2 astrocytoma

• Peak in 30’s
• Most common sx: seizure, so give antiepileptics, if coming to ED -> steroids
• Hypo in T1, hyper in T2, no enhancement
• If contrast enhancement -> malignant transformation
• Natural Hx:
  • Remains low grade many years, survival = 9 yrs
  • Might progress to higher grade, but we don’t know when, so observe

 

3. Glioblastoma multiform (GBM): Grade 4 astrocytoma

• Most common supratentorial tumor in adults
• Causes:
  • De novo
  • De-differentiation of lower grade glioma
• CT: irregular enhancement + central hypodensity (necrosis)
• MRI: severe midline shift and edema, “butterfly”
• Why biopsy? Mimics TB
• Goal of treatment: prolongs quality of survival

 

4. Sub ependymal giant cell astrocytoma: Grade 1 astrocytoma

• In tuberous sclerosis
• Most commonly in lateral ventricles -> hydrocephalus

 

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Oligodendroglial Tumors: 

1. Oligodendroglioma (grade 2)

2. Anaplastic oligodendroglioma

• Do chromosomal analysis of the tumor -> if mutations in chr 19 + 1 -> respond well to chemo

 

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Ependymal Tumors: 

1. Ependymoma:

• Third most common tumors in children
• Can be infratentorial (> 2 yrs), supratentorial (< 2 yrs)
• Most commonly in post fossa, why? They arise from ependymal cells lining 4^th ventricle -> hydrocephalus
• Treatment -> surgery

 

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Choroid Plexus Tumors:

1. Choroid plexus papilloma: grade 1

• Adults; 4^th ventricle, children; lateral ventricles -> hydrocephalus
• CT: dilated ventricles + lobulated tumor inside

2. Choroid plexus Carcinoma: grade 3-4

 

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Pineal Tumors: 

• Presentation:
  • Hydrocephalus
  • Parinaud’s syndrome (upward gaze palsy)
  • Precocious puberty
• Work up:
  • MRI: enhanced lesion, calcification, hydrocephalus
  • Serum markers -> AFP, HCG, CL
• Management -> third ventriculostomy + biopsy

 

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Medulloblastoma:

• Embryonic tumor
• Most common malignant pediatric brain tumor
• Most commonly in post fossa -> N\V -> easily missed -> pt can die
• Cerebellar tumor only
• Tends to metastasize -> CSF seeding -> lumbar spine
• Treatment: surgery + radio\chemo

 

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Vestibular Schwannoma: 

• From 8^th cranial nerve -> hearing loss, tinnitus, vertigo
• Usually unilateral, if bilateral -> pathognomic of NF type 2
• Most commonly -> cerebellopontine angle (CPA)

 

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Meningioma:

• Most common non-glial primary tumor + most common extra-axial primary CNS tumor -> can be found incidentally
• Female predication (esp in spine)
• Slowly growing lesion
• Arise from arachnoid villus
• Doesn’t infiltrate brain tissue
• Radiology:
  • Attached to dura -> dural tail
  • Hyperostosis of overlying skull

 

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Pituitary Tumors: 

• Ant pituitary (adenohypophysis) -> location of pituitary tumor itself
• Post pituitary (neurohypophysis) -> location for metastasis
• Closest structure to the pituitary? 6^th (abducent) -> first to attack when expanding
• Presentation:
  • Hyperfunctioning
  • Mass effect -> bitemporal hemianopia
• Investigations:
  • Brain MRI
  • Hormonal profile
  • Visual acuity
• Surgery -> transphenoidal

 

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Pituitary Apoplexy: 

• Pituitary tumor -> infarction or hemorrhage -> sudden expansion -> severe headache and visual changes
• Risk factors: pregnancy
• Treatment: prompt steroids

 

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Download the PDF version: here

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References:

• Dr Aloraidi’s lecture