CNS Tumours Flashcards
Which is the second most common tumour in children after leukaemia?
CNS tumours
CNS tumours make up what percentage of malignant neoplasms?
2%
Which are the 2 most common types of CNS tumours?
Gliomas and meningiomas
What is the age distribution of CNS tumours?
Bimodal - 2 peaks one in childhood, one in adults
What is a PNET tumour?
Primitive neuroectodermal tumor (PNET) is a malignant neural crest tumor.
What are the most common sight and type of CNS tumours in children?
1) Cerebellum
2) PNET
What is the most common sight and which are the 2 most common tumours in adults?
Cerebrum
1) Glioma
2) Meningioma
Which is the most common type of CNS tumour in males?
Glioma
What is the most common type of CNS tumour in females?
Meningioma
What are the 4 types of glial cells and what is their rough function?
1) Astrocytes (support and protect)
2) Oligodendrocytes (myelin)
3) Ependymal cell and choroid plexus cells (CSF)
4) Microglia (defense)
What is the difference in treatment for a benign and malignant tumour?
Benign: surgery
Malignant: surgery and adjuvant therapy
Do benign tumour recur?
No, tend to get no recurrence with benign tumours
What would the grade of a benign brain tumour?
Grade 1
What are the 4 histological criteria for malignancy in brain tumour?
1) Cellular density and atypia
2) Mitotic activity (abnormal numbers of mitotic figures)
3) Necrosis (growing so fast some dont get enough resources and die)
4) Vascular proliferation
What are the 4 WHO classifications of CNS tumours?
1) Glioma - astrocytoma, oligodendroglioma, ependymoma
2) Meningioma
3) PNET (medulloblastoma)
4) Nerve sheath tumours: schwannoma, neurofibroma
Give the 3 microscopical features of astrocytic tumours?
1) Fine fibrillary and microcystic background
2) increased cellular density
3) Pleomorphism (variation in size, shape and chromasia)
Give the 4 features of a grade 2 diffuse astrocytoma?
1) Infiltrative, microcystic, fibrillary
2) Low cellular density
3) Mild atypia
4) No mitotic activity
Give the 3 features of a grade 3 astrocytoma?
1) Moderate cellular density
2) Moderate pleomorphism
3) Mitoses
Give the 3 features of a grade 4 glioblastoma?
1) High cellular density and mitoses
2) Necrosis
3) Vascular proliferation
Give the 4 features of a pilocytic astrocytoma, who does it most commonly occur in?
Children (cerebellum)
1) Well defined, cystic
2) Pilocytes
3) Rosenthal fibres
4) Vascular proliferation
Give the 3 features of a grade 2 or 3 oligodendroglioma?
1) Round uniform nuclei with clear cytoplasm (fried egg appearance)
2) Arborising capillaries (chicken wire)
3) Calcifications
Give the 3 features of an ependymoma grade 2 or 3?
1) Well defined tumour - ventricles
2) Pseudorosettes
3) Round small uniform cells
What is the most common group of people and sight of meningioma?
Females - adults
Dura
What are the 2 main features of a meningioma?
1) Well defined, extra-axial tumour
2) Whorls, psammoma bodies
In which group and sight does a PNET (medulloblastoma) grade 4 most commonly occur?
Children in the cerebellum
What are the 4 features of PNET tumours?
1) Very high cellular density
2) Anaplastic hyperchromatic cells
3) Frequent mitoses and apoptosis
4) Rossette formation
What is the most common type of nerve sheath tumour?
Schwanomma
Schwannoma most commonly occurs on which cranial nerve?
8th cranial nerve
Neurofibromas commonly occur in which structures and are rich in what substance?
Spinal nerves
Rich in collagen
Radiotherapy treatment can cause which type of brain tumour?
Meningioma
Immunosuppression can lead to which tumour?
Lymphoma
Which familial syndrome can lead to the development of neurofibroma?
Neurofibromatosis 1
Which familial syndrome can lead to the development to schwannoma?
Neurofibromatosis 2
What are the 2 properties of stem cells?
1) Self-renewal
2) Differentiation
What are the 3 signalling pathways which regulate self renewal during normal stem cell development and during transformation?
1) Wnt
2) Shh
3) Notch
A mutation in which signalling pathway can lead to the development of a medulloblastoma?
Shh
What is the difference between a primary and secondary glioblastoma?
Primary glioblastoma - formed by a series of mutations in the cell of origin
Secondary glioblastoma - mutations in the cell of origin give rise to astrocytomas, oligoastrocytomas or oligodendroglioma then mutations in these lead to the formation of a secondary glioblastoma
Which 4 markers are currently most relevant for molecular diagnostics of glioma (ie. working out the type and grade)?
1) MGMT promoter methylation
2) 1p/2q deletion
3) IGH1/IGH2 mutation
4) BRAF duplication/fusion
Other than the histological diagnosis and WHO grade what 5 other factors determine the prognosis of brain tumours?
1) Age: better in younger patients
2) Site
3) Surgical resection
4) Adjuvant therapy
5) Genetic
What is the prognosis for a glioblastoma WHO grade 4?
Survival time
What is the prognosis for a meningioma WHO grade 1?
Benign
