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)

 


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

Brain tumors 1

 

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
Brain tumors 2
Glioblastoma multiform

 

4. Sub ependymal giant cell astrocytoma: Grade 1 astrocytoma

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

 


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

 


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 4th ventricle -> hydrocephalus
  • Treatment -> surgery

 


Choroid Plexus Tumors:

1. Choroid plexus papilloma: grade 1

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

2. Choroid plexus Carcinoma: grade 3-4

 


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

 


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

 


Vestibular Schwannoma: 

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

 


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

 


Pituitary Tumors: 

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

 


Pituitary Apoplexy: 

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

 


Download the PDF version: here


References:

  • Dr Aloraidi’s lecture

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