neuroonco with steveeeee Flashcards
How are CNS tumours classified?
Primary - if they originate in the CNS
Secondary - if they are mets (most common in adults)
How common are primary CNS tumours in adults and children?
In adults - rare (1-2 percent)
In children - most common in children under 14 years old (25 percent)
How do we classify CNS primary tumorus?
Extra axial aka coverings - tumours of bone, soft tissue, meninges, nerves
INTRA axial parenchymal - aka brain cells - glial astrocytes and oligodendrocytes, neurons and neuroendocrine cells
Lymphomas and germ cell tumours are also intra axial
Which CNS tumours are more malignant?
Extra axial - less malignant
Intra axial - more malignant since they infiltrate the tissue of the brain
Causes if CNS tumours
Unknown
Radiotherapy to head and neck
Genetic disposition (less that 5 percent)
Name 5 familial CNS tumour syndromes and their cancers
Neurofiboromatosis 1 - neurofiboroma astrocytoma
Neurofibroamatosis 2 - schwanomma, meningioma
Brain tumour polyposis syndrome 1 - malignant gliomas
Gorlin syndrome - medulloblastoma
Von Hipple Lindau - Hemangioblastoma
Signs and symptoms of CNS tumours
Space occupying lesions, therefore you get intracranial hypertension symptoms:
-Headache and vomiting
-change in mental status
If it’s above tentorium:
focal neurological deficity
Seizures
Personality changes (esp if in frontal lobe)
Infratentorial
Cerebella ataxia
Long tract signs
Cranial nerve palsy (esp oculomotor nerve if it’s pressing on it)
Treatment option for CNS tumours
Surgery - resection, but this depends on the type of tumour. Resection means that the surgeon will need to resect a part of normal tissue around the margin of the tumour.
Radiotherapy - low and high grade gliomas
metastases, bening tumours
Chemotherapy
Mainly for high-grade gliomas (temozolomide) and lymphomas
Where do medulloblastomas come from?
embryonal cells
WHO grading of CNS tumours
Grade 1 - benign long term survival
Grade 2 - more than 5 years
Grade 3 - less than 5 years
Grade 4 - less than 1 year
Note - some tumours have only one possible grade, but others have more than one grade .
Diffuse glial tumours
Diffuse gliomas - grade 2 or above
Seen in adults
Supratentorial
Malignant progressoin
Astrocytomas (g2-4)
Oligodendrocytomas (grade2-3)
Circumscribed gliomas
Seen more in children in posterior fossa, rare malignant transformation
Pilocytic astrocytoma (g1)
Subependyml giant cell astrocytoma (g1)
Ependymomas
Most common gliomas seen in kids under the age of 14?
PILOCYTIC ASTROCYTOMAs (fifth of all gliomas in kids)
BRAF gene mutation in 70 percent of pilocytic astrocytomas
well circumscribed lesion
Pilocytic = piloid hairlike cells
Rosenthal fibres seeen o nH and E
Slow growing, low mitotic activity
Diffuse gliomas and their key mutation
Astrocytoma - IDH mutant, point mutation
Oligodendroglioma - IDH mutant
IDH mutation is associated with longer term survival, point mutation
Astrocytoma sings
Low choline/creatine raio on MR spectroscopy
T1 - hypointense
T2 - hyperintense
Astrocytoma histology signs
Astrocytoma
Slow growth
No vascular proliferation
IDH1 mutation can be detected on immunocytochemistry
What is the worst type of glioma?
Glioblastoma multiforme (GBM) grade 4
Supratentorial
Median survival only 8 months
Most patients over the age of 50 years
IDH1 wildtype
TERT, PTEN, EGFR mutations
MRI - heterogenous
Histopathology of GBM
High cellularity. lack of clean margins
Necrosis
Neoangiogenesis
Meningioma
Well circumscribed
Meningothelial cells of arachnoid matters
Grade 1 - 80 percent
Grade 2 -
Grade 3
Grading is the most useful marker of recurrence
TERT mutation
Methylome
What do you have to check?
High mitotic activity - you count the number
Microscopic brain invasion -
CNS mets are most commonly found where?
Grey-white matter junction
OR
Leptomeningeal ????
Where do mets come from?
Lung cancer
Breast cancer
Melanoma
Renal cell carcinoma
Medulloblastoma
Embryonal tumour - second most common brain malignancy in children despite being rare
Outcome improved with radiotherapy
histological profile? medulloblastoma
Synpatophysin
GFAP
Ki67
High grade, poorly definitiated
