Brain tumours Flashcards
Primary brain tumours:
- Which cell types are the most common? [2]
Secondary brain tumours:
- Mets. from where is most common? [3]
Primary brain tumours:
- Tumours from glial and meningeal cells are the most common
Secondary brain tumours:
- Lung, Breast and melanoma most common
NB: secondary indicates stage IV disease ( Malignant)
Which risk factors increase the risk of brain cancers? [4]
- Majority are sporadic
- Links to ionizing radiation (e.g. from previous childhood brain tumour)
- Immunosuppression - Primary CNS lymphoma
- Familial cancer syndromes e.g.
Bilateral acoustic scwhannommas are indicates which cause of brain tumours? [1]
Neurofibromatosis type II
Which genetic causes can cause brain tumours? [3]
Which types of brain cancers do they cause? [3]
Neurofibromatosis type I:
- Neurofibromas
- Malignant nerve sheet tumour
- optic nerve glioma
Neurofibromatosis type II:
- Bilateral acoustic scwhannommas
von Hippel-Lindau syndrome:
- Haemangioblastoma
Describe the difference in presentation / dx of NF1 vs NF2 [+]
A patient should be diagnosed as having NF1 if two or more of the following features are present:
* Six or more café-au-lait macules over 5 mm in greatest diameter in prepubertal individuals and over 15 mm in greatest diameter in postpubertal individuals.
* Two or more neurofibromas of any type or one plexiform neurofibroma.
* Freckling in the axillary or inguinal regions.
* Optic glioma (tumour on the optic nerve).
* Two or more Lisch nodules (iris hamartomas).
* A distinctive osseous lesion such as sphenoid dysplasia or thinning of long bone cortex with or without pseudoarthrosis.
Diagnostic Criteria for Neurofibromatosis Type 2 (NF2):
* Bilateral vestibular schwannomas. The definitive diagnosis is made by magnetic resonance imaging. This remains the hallmark feature of NF2 even though it may not be initially present in young patients who eventually manifest other stigmata of NF2.
Describe what is meant by a Lisch Nodule [1]
small, raised, and often pale brown spots (melanocytic hamartomas) found on the iris, the colored part of the eye, and are a common characteristic of Neurofibromatosis type 1 (NF1)
Describe the medical [2] surgical [3] management of NF
Medical Management:
* Analgesia: Non-steroidal anti-inflammatory drugs (NSAIDs) or opioids may be required for pain related to plexiform neurofibromas.
* Antihypertensives: Angiotensin-converting enzyme inhibitors or calcium channel blockers are recommended for hypertension secondary to renal artery stenosis in NF1 patients.
Surgical Management:
* Plexiform Neurofibromas: These can cause significant morbidity due to their size and location. Surgical debulking is often necessary but complete resection is usually not possible due to the infiltrative nature of these tumours.
* Optic Pathway Gliomas: Surgery may be indicated if there is rapid progression of symptoms despite medical therapy. However, it carries significant risk due to the proximity of critical structures.
* Scoliosis: Orthopaedic intervention may be required for progressive scoliosis associated with NF1. Spinal fusion might be necessary for severe cases.
Von Hippel-Lindau (VHL) syndrome is an autosomal dominant condition predisposing to neoplasia. It is due to an abnormality in the VHL gene located on short arm of chromosome 3
What are the features? [6]
cerebellar haemangiomas: these can cause subarachnoid haemorrhages
retinal haemangiomas: vitreous haemorrhage
renal cysts (premalignant)
phaeochromocytoma
extra-renal cysts: epididymal, pancreatic, hepatic
endolymphatic sac tumours
clear-cell renal cell carcinom
H - Haemangiomas - cerebellar/retina/spinal cord
I - increased risk of clear cell renal cell cancer
P - pheochromocytoma
P - pancreatic cyst
E - Endolymphatic sac tumours
L - liver cyst, kidney cyst, epidydmal cyst
3 words in the syndrome - CHR 3
What’s important to note about weight loss as a symptom for brain tumour? [1]
Weight loss is more associated with with met. brain tumour than primary causes
What are the symptoms of brain tumours? [+]
Raised intracranial pressure
* Nausea
* Vomiting
* Swollen optic discs
* Reduced conscious level
* Dull, constant, and often bilateral headache. Worse in morning and exacerbaed by positional changes (bending over or sneezing). May occur at night
Focal neurological deficits:
* Weakness
* Sensory changes
* Language defects (e.g. aphasia)
* Visual defects (i.e. due to compression along the visual cortex)
* Dysphasia (receptive or expressive)
Seizures
* Focal or generalised
* Seizures affect up to 80% of patients with primary brain tumours and 20% of those with metastatic brain tumours
Unusual change in personality and behaviour
- If frontal lobe tumour
NB - difficult to differentiate between post-ictal state vs brain tumour after a seizure.
What are the signs of brain tumours? [+]
Papilloedema
* Blurring of the optic disc margin
* Elevated optic disc (look for the way the retinal vessels flow across the disc to see the elevation)
* Loss of venous pulsation
* Engorged retinal veins
* Haemorrhages around the optic disc
* Paton’s lines, which are creases or folds in the retina around the optic disc
Muscle weakness
- Brain tumours can cause weakness or paralysis on one side of the body, difficulty walking, and coordination problems.
Sensory losses:
- numbness, tingling, and loss of sensation in different parts of the body.
Endocrine issues
- Hypertension
- Raised prolactin
- Cushings syndrome
- Acromegaly
Describe the flow of CSF throughout brain xo
There are four ventricles in the brain: two lateral ventricles, the third and the fourth ventricles.
The ventricles containing CSF.
Lateral ventricles –> interventricular foramina –> third ventricle –> cerebral aquaduct –> 4th ventricle
The CSF provides a cushion for the brain tissue. CSF is created in the four choroid plexuses (one in each ventricle) and by the walls of the ventricles. CSF is absorbed into the venous system by the arachnoid granulations.
Describe what happens due to ICP increasing in the brain [1]
Increased CSF causes a compensation of venous blood going into brain, the brain parenchyma will herniate through the foramens / coning
(According to Monro Kellie doctrine)
3 layers: brain parenchyma, CSF and blood will compensate as much as possible but exist within a closed structure.
Which investigations should you use to investigate ?brain tumour [+]
MRI
* Imaging of choice
* Gadolinium can distinguish between oedema and tumour
* Space occupying lesion - look for midline shift
Dynamic imaging:
- PET
- SPECT
- MR Spectroscopy
Biopsy gives the definitive histological diagnosis, usually obtained during surgery to remove the tumour.
§Gliomas are brain tumours starting from the glial cells, which support the neurons/nerve cells in the brain.
What are the three types of glioma? [3]
§ Astrocytoma
§ Oligodendroglioma
§ Ependymoma
Which type of glioma is most common adults and children? [1]
Astrocytoma
NB:
*The most common types of brain tumour in adults are:
◦ Grade 3 astrocytoma - also called anaplastic astrocytoma
◦ Grade 4 astrocytoma - also called glioblastoma multiforme (GBM)
State the different names for the WHO grade astrocytic tumours [3]
WHO Grade I: pilocytic astrocytoma
WHO Grade II: diffuse astrocytoma
WHO Grade III: anaplastic astrocytoma
Pilocytic astrocytoma:
- Where do they tend to grow? [1]
- Which populations do they tend to present in?
- How severe is it? [1]
- histological feaures? [2]
Pilocytic astrocytoma:
- WHO grade I
- Children or YA
- Cerebellum growth
- Dense pink rosenthal GFAP fibres; Loose textured multipolar cells with pink globular
Diffuse astrocytoma:
- Which populations do they tend to present in? [1]
- histological feaures? [2]
- Other important features? [1]
Pilocytic astrocytoma:
- WHO grade II
- 30-40 yrs olds; esp. males
- Plump pink, glassy cell bodies with short, stubby cytoplasmic processes
- Intrinsic tendency for malignant transformation to anaplastic and GBM
What is Grade III astrocytoma called? [1]
Anaplastic astrocytoma
Anaplastic Astrocytoma:
- Population? [1]
- Location? [1]
- Histology? [2]
§Primarily affects adults
§Common in cerebral hemispheres
§Nuclear atypia, increased cellularity and significant proliferation activity
Most common and malignant CNS tumour in adults is? [1]
Glioblastoma Multiformis (GBM)
Describe the different causes of Glioblastoma Multiformis (GBM) [4]
Transformation from low grade
gliomas (5%)
Genetic disorders eg neurofibromatosis, Li fraumeni
Previous radiotherapy
Environmental factors proposed eg smoking/ pesticides
95% de novo
GBM
5% transform from a low grade glioma –
* these exhibit [] gene mutation in 80% of cases
5% transform from a low grade glioma –
* these exhibit IDH-1 gene mutation in 80% of cases
