Neurooncology Flashcards
What are the classifications of primary CNS tumours based on location?
EXTRA-AXIAL (COVERINGS):
Tumours of bone, cranial soft tissue, meninges, nerves
INTRA-AXIAL (PARENCHYMA):
Derived from the normal cell populations of the CNS e.g. glia, neurons, neuroendocrine cells. Derived from other cells types lymphomas, germ cell tumours.
What are more common CNS tumours?
Non-malignant tumours are more common than malignant tumours
What is the aetiology of CNS tumours?
Only known environmental factor is radiotherapy to head and neck: meningiomas, rarely gliomas.
Genetic predisposition <5% of primary brain tumours
- Familiarity
- Familial syndromes
What is the chromosome and loci for NF1?
17q11
What is the chromosome and loci for NF2?
22q12
What are other genetic risk factors for CNS tumours and their chromosomes and loci?
Schwannomatosis (22q11)
Tuberous Sclerosis 1 (9q34) and 2 (16p13)
Brain tumour polyposis syndrome 1 (PMS2 7p22, MSH6 2p16) and 2 (APC 5q21)
Li-Fraumeni (p53 17p13)
Cowden syndrome (PTEN,10q23.3)
Gorlin syndrome (PTCH1, 9q31)
Von Hippel Lindau (3p25)
Rhabdoid tumour predisposition (SMARCB1, 22q11)
What do different CNS tumour syndromes result in?
NF1: Neurofibroma, pilocytic astrocytoma
NF2: Schwannoma, meningioma
BTP, Li-Fraumeni: Malignant gliomas
Gorlin: Medulloblastoma
VHL: Hemangioblastoma
What are signs and symptoms of CNS tumours?
Intracranial hypertension:
- Headache, vomiting
- Change in mental status
Supratentorial:
- Focal neurological deficit
- Seizures
- Personality changes
Subtentorial:
- Cerebellar Ataxia
- Long tract signs
- Cranial nerve palsy
What is the most common type of CNS tumour in adults?
Metastatic CNS tumour
What is the most common type of CNS tumour in children?
Pilocytic astrocytoma
What is the management for CNS tumours?
SURGERY:
- Maximal safe resection with minimal damage to the patient
- Gives best outcome
- Age and performance status
- Resectability: location, size, number of lesions
RADIOTHERAPY:
- Low and high-grade gliomas, metastases, selected benign tumours
- External fractionated RT, stereotactic radiosurgery
CHEMOTHERAPY:
- Mainly for high-grade gliomas (temozolomide) and lymphomas
- Biological agents (EGFR inhibitors, PD-L1 inhibitors etc)
What are the diagnostic and therapeutic objectives for CNS tumours?
Craniotomy for debulking: Subtotal and complete resections (as much tumour as possible).
Open biopsy: Inoperable but approachable tumours (about 1cm) – usually representative.
Stereotactic biopsy: If open biopsy not indicated (about 0.5cm tissue) – tissue may be insufficient.
What is histopathology and molecular pathology used for in CNS tumours?
To provide a definitive and complete diagnosis.
To guide treatment: Predictive tests assays for target therapy.
To assess treatment response.
What is the WHO classification of CNS tumours?
Tumour type: Putative cell of origin or lineage of differentiation.
Tumour grade: Tumour aggressiveness.
Molecular profile: Expanded compared to previous 4th edition (genetics, methylome), most tumour types have molecular markers.
NO TNM STAGING
What is tumour typing for CNS tumours?
Tumour type: Histological type
Tumour defined by histological features
Tumour names often derive from putative cell of origin or differentiation
Histological type predicts tumour behaviour.