Tumours of the CNS Flashcards
what are the most common CNS tumours
gliomas, meningiomas
what is the occurrence distribution of tumours of the nervous system
age distribution is bimodal
Adults: cerebrum, glioma and menigioma.
where are tumours commonly found in children in the cerebrum or cerebellum
cerbellum (PNET and medullablastoma)
where are tumours commonly found in adults in the cerebrum or cerebellum
Glioma and Meningioma
do males have a increased risk of glioma or meningioma
glioma
do females have an increased risk of glioma and meningioma
meningioma
are neuronal tumours common or rare
rare
Do neurones communicate with the blood supply
no
how many astrocytes are there per neurone
10 astrocytes
define astrocyte
support and protect
connect neurones with blood supply so that they can access the metabolites they need to function.
define oligodendrocyte
myelin- insulate neurones
define ependymal cells and choroid plexus cells (CSF)
produce CSF
protect brain from trauma
control external environment
define micoglia defense
comes from bone arrow
sends astrocytes signal so that inflammatory cells can enter the blood brain barrier.
what are the 4 types of glial cells (support cells)
astrocytes
oligodendrocytes
ependymal cells and choroid plexus
micoglial cells (defense)
what is tumour of the neurone known as
ganglioma
what is tumour of the glial cells known as
glioma
what is tumour of the meninges known as
meningioma
how many layers is the cerebrum
6 layers
how many layers is the cerebellum
3 layers
how are CNS tumours diagnosed
Histology- name of tumour
biological behaviour- grade of the tumour.
do you have micoglial tumours
No
what are the characteristic features of a benign tumour
slow growing respect surrounding tissue no/ slow progression no recurrence surgery -depends on postion
what are the characteristic features of a malignant tumour
rapid growing invade and destroy surrounding tissue progress recurrent surgery and adjuvant therapy (radiotherapy and chemotherapy)
what grade are benign tumours
grade 1
are all graded tumours malignant
No
grade one can be benign.
what histological changes are present in a malignant tumour
cell size and shape
mitotic activity
Necrosis-TNF to kill other cells
vascular proliferation- increase endothelial cells to supply tumour.
what are the 3 types of gliomas
Astrocytic tumours
Oligodendroglioma
Ependymoma
what are the 2 types of nerve sheath tumours
Schwannoma and neurofibroma
Microscopical features of astrocytic tumours
Fine fibrillary and microcystic background
Increased cellular density
Pleomorphism ( variation in size, shape and chromasia)
what are the features of diffuse astrocytoma II
infiltrative, micro cystic fibrillary,
low cellular density
mild atypia
no mitotic activity- grade 2
what are the features of Anaplastic astrocytoma III
Moderate cellular density
Moderate Pleomorphism
Mitoses - grade 3
what are the features of glioblastoma
High cellular density and mitoses
Vascular proliferation
Necrosis
Histology- necrosis occurring in the centre and tumour cells are trying to escape
is the men age for developing glioblastma younger or older than anapaestic astrocytoma
older
what are the features of pilocytic astrocytoma
Children, cerebellum Well-defined, cystic Pilocytes Rosenthal fibres Vascular proliferation
what are the features of oligodendroglioma II/III
Round uniform nuclei with clear cytoplasm (fried-egg appearance)
Arborising capillaries (chicken wire)
Calcifications
what are the main features of Ependymoma II / III
Well-defined tumour, ventricles
Pseudorosettes
Round small uniform cells
what are the main features on meningioma
Females, dura, adults
Well-defined extra-axial tumour
Whorls, psammoma bodies
Histology- tumour cells whirl around each other.
what are the main features of PNET
Children, cerebellum Very high cellular density- no cytoplasm seen in histology. Anaplastic hyperchromatic cells Frequent mitoses and apoptosis Rosette formation
what are the main features of
Spindle-cell tumours Schwannoma I – 8th cranial nerve – Biphasic pattern: loose and dense areas – Reticulin rich Neurofibroma I – Spinal nerves – Rich in collagen
what causes meningioma
radiotherapy
what causes lymphoma
immunosupression
what causes familial syndromes
NF1, NF2
Mutations in any of Wnt 7, SHH and notch leads to what
tumours.
MGMT promoter methylation is a predictive marker of which type of CNS tumour to akylating chemotherapy
glioblastomas
1p/19q deletion is a predicative marker of n prognosis of what CNS tumour is patients receiving adjuvant radio and/ or chemotherapy.
(oligodendro)glial tumor
What CNS tumours are IDH1/IDH2 mutations a diagnostic marker for
II and III gliomas as well as secondary glioblastomas
What CNS tumours use BRAF duplication/fusion to determine the diagnosis of tumours.
Diagnostic marker for pilocytic astrocytomas, helpful to distinguish these from diffuse astrocytomas
