76. Brain Tumors

Question 1

Most common tumor in brain (Primary or Secondary)?

Most common primary tumor in the brain?

Most common primary malignant tumor in brain?

What is the gold standard for dx brain tumor?

Answer 1

Secondary Tumor (Metastasize from melanoma, breast cancer, lung cancer)

Meningioma

Glioblastoma Multiforme (GIV astrocytoma)

MRI with IV Contrast (but surgical biopsy/excision needed for histo dx)

Question 2

What are the characteristics of a brain tumor HA

Answer 2

rare to exist as only sx

• mild onset, begins when pt wakes and disappears during day
• returns every morning
• gradual increase in freq, duration, severity
• later: signs of high ICP (drowsiness, nausea, vomiting) - worsens with changing ICP (Valsalva, head shaking, straightening from bent postion)

Question 3

Glioma

• origin cell
• categories and classifications
• how to identify certain category with a stain

Answer 3

arises from neuro-epithelial tissue
Category: by tissue subgroup: astrocytoma vs. oligodendroma
Astrocytic tumors: astrocyte (component of BBB, support brain/SC) identified by staining for GFAP
Grading I-IV - IV most aggressive
I: Pilocytic Astrocytoma (non-infiltrative)
II: Diffuse Astrocytoma (infiltrative)
III: Anaplastic Astrocytoma (infiltrative)
IV: Glioblastoma Multiforme (infiltrative)

Question 4

Glioblastoma Multiforme

• grade/origin
• prognosis
• onset, localization
• mgmt
• imaging

Answer 4

• GIV astrocytoma, most common malignant primary tumor
• poor prognosis, median survival (16-21mo)
• onset: 64yo
• location: cerebral hemisphere (causes high ICP/focal deficit)
• mgmt: surgery - obtain tissue for dx; goal maximal resection (less mass effect, better tx response, respect brain fx) - NOT CURATIVE, needs radiotherapy (affects dividing cells - no risk to neurons), chemotherapy (Temozolomide), tumor treating fields (disrupt mitosis with electrodes on skin)
• imaging: mass w/ central necrosis, vasogenic edema

Question 5

Oligodendroglioma

• location
• grades
• genetics
• CP
• Tx
• Prognosis

Answer 5

Location: supratentorial, in frontal lobes (white matter but infiltrates inward)
GII, GIII
genetics: 1p19q translocation co-deletion ALWAYS present
CP: focal seizure in young adult (median age 41), prolonged period of focal seizures prior to dx
tx: maximum surgical resection, difficult due to diffuse infiltration + chemotherapy
px: transforms to GIII - causes death; median survival 15 years with tx

Question 6

Meningioma

• grade
• CP
• Risk Factors
• Imaging
• tx

Answer 6

Intracranial tumors from cells in meninges
GI (benign, slow growing, rarely infiltrative)
CP: any age (median 64) with focal seizures/neuro deficits from brain/CN compression
RF: genetic (NF2), exposure to ionizing radiation
MRI: diffuse contrast enhancement (because tumor outside BBB in meninges)
Tx: observation if sx controlled; surgery (GI resection is curative)

Question 7

Vestibular Schwannoma

• what is it
• types
• CP
• tx

Answer 7

slow growing (vestibular system can compensate)
unilateral - sporadic
bilateral - pathognomonic for NF2 (merlin protein gene defect)
CP: gradual unilateral hearing loss, tinnitius, vague dizziness, CN7 dysfx
tx: surgery is curative! (high morbidity - risk of CN8/CN7 deficits from sx/tumor, and post-op persistent HA common)

Question 8

CNS Lymphoma

• histo
• primary vs. secondary cause
• pathogenesis hypothesis (2)
• CP
• why not use steroids?
• tx

Answer 8

H: perivascular lymphocyte proliferation
2o: metastases from systemic disease
1o: type of Non-Hodgkins Lymphoma (arises/restricted in CNS)
PG - (1) CNS Sanctuary - hemopoietic tumor develops outside CNS, seeds brain - allows tumor to grow (immunoprivileged); (2) Inflammatory - lymphocytes traffic to CNS due to inflammatory process - there they transform to malignant cells

CP: median age 66, located in frontal lobes, corpus callosum, deep periventricular brain, most common sx is cognitive impairment/behavioral change (seizures rare)

CS use: decrease edema and kill lymphoid cells, but CS-resistant tumor recurs despite continuous use

tx: induction chemotx (MTX high dose to cross BBB - curative or survival of 3-5yrs) and Consolidation tx (radiotherapy of whole brain - risk cognitive decline)