Histopathology 14 - Neuro-oncology Flashcards
Which 3 types of cancer are most likely to metastasise to the brain?
Lung
Breast
Malignant melanoma
What is the most common form of primary brain tumour?
Astrocytoma
Which genetic syndrome is associated with meningioma?
Neurofibromatosis type 2
What type of tumour is being described by “a ventricular tumour that presents with hydrocephalus”?
Ependyoma
Which brain tumour is an indolent CNS tumour of childhood?
Pilocystic astrocytoma
Which type of brain tumour is soft, gelatinous and can become calcified?
Oligodendroma
Which CNS tumour does Von Hippel-Lindau predispose to?
Hemangioblastoma
Which CNS tumour does tuberous sclerosis predispose to?
Giant cell astrocytoma
Recall the order in which imaging should be performed in CNS tumour investigation
- CT
- MRI (T1 and without contrast)
- MR spectroscopy for gliomas (useful prognostically)
Recall the 4 factors that guide grading of brain tumours
Morphology
Proliferative activity
Cell differentiation
Necrosis
Recall the survival prediction for each grade of CNS tuour
Grade 1 = longterm
Grade 2 = >5 years
Grade 3 = <5 years
Grade 4 = <1 year
What are the 2 broad subtypes of glial tumours, and in which age groups are they typically seen?
Diffuse (adults) or circumscribed (children)
What grade are circumscribed glial tumours?
1 or 2
What is the most common type of circumscribed glial tumour?
Pilocystic adenoma
Mutation of which gene is associated with circumscribed glial tumours?
BRAF gene mutation
Describe the progression of all diffuse glial cell tumours
Cannot be removed surgically, so all progress to glioblastoma within 10 years
Which gene mutation is associated with diffuse glial cell tumour prediliction?
IDH gene
How can glioblastoma and diffuse astrocytoma be differentiated on CT?
Glioblastoma = enhancing
Diffuse astrocytoma = non-enhancing
Which gene mutation is always seen in oligodendroglioma?
IDH gene
What is the WHO grade of oligodendroglioma?
Stage 2 - 3
What is the pathognemonic histological finding in oligodendroglioma?
Fried egg cells
How is oligodendroglioma most often managed?
Usually appropriate for surgical excision as often well-circumscribed
What must be investigated in the case of multiple meningiomas?
Neurofibromatosis type 2
What is the most important factor to assess when grading meningiomas?
Mitotic activity
What is the most common type of embryonal CNS tumour?
Medulloblastoma
Where do medulloblastomas always form?
In cerebellum near 4th ventricle
What is the pathognemonic histological finding in medulloblastoma?
Very poorly differentiated ‘small round blue cells’
Which subtype of medulloblastoma has the best prognosis?
WNT-activated subtype
What is the basis of epigenetic profiling in CNS tumours?
DNA methylation of CpG islands
