Brain Tumours Flashcards
Which instance is higher primary brain tumours or metastatic?
Metastatic neoplasms
Appearance of metastatic brain tumours?
Multiple, well-delineated spherical nodules that are randomly distributed
2 most common primary sites for malignant brain tumours to arise from?
Breast
Lung
But any malignant tumour can metastasise to there
Difference between primary brain tumours and epithelial tumours?
Isn’t always a distinct cut off for benign and malignant in primary. There is in epithelial.
What are gliomas?
Tumours of the neuroepithelial (neuroepithelial origin)
Where do gliomas usually occur?
Usually seen within the hemispheres
-Although occasionaly in cerebellum, brainstem or cord
Cause of gliomas?
Unknown
How do gliomas spread?
By direct invasion
-Never metastases (virtually) outside the CNS
Main type of gliomas?
Astrocytomas and oligodendrogliomas
More rare types of gliomas?
Ependymal cell tumours
Pineal cell tumours
Embryonic cell tumours
What are astrocytomas?
Gliomas that arise from astrocytes
How are astrocytomas histologically graded?
Grade I-IV
Difference between grade I and grade IV astrocytomas?
Grade I: Grows very slowly over many years
Grade IV: Causes death within several months
Grade II astrocytomas?
Blurring between grey and white matter which makes them more difficult to dissect
Grade IV astrocytomas shows?
Marked abnormalities with haemorrhagic change, necrosis, loss of integrity of tissues and surrounding oedema
Causing midline shift
What are grade IV astrocytomas termed?
Glioblastomas/glioblastoma multiforme
Talk to me about glioblastoma multiforme?
Commonness (?), occurs, prognosis
- Commonest glial tumour
- May occur de novo or following history of low grade astrocytoma
- Highly malignant
- Prognosis of patients is v poor
What are gliomas that arise from dendrocytes called?
Oligodendroglioma
How oligodendrogliomas exist and what occurs to them?
Grow very slowly over several decades and calcification is common
What is the fancy name for childhood brian tumours?
Tumours of neuronal cell types
What can fully differentiated neurons not do?
Neither multiply or give rise to neoplasms
What type of tumours are seen in infancy or childhood?
Derived from?
Tumours of neuronal cell types
-Derived from primitive nerve precursors (blast cells)
What are blast cells?
Basically a precursor to mature neurons
What do you call a neuronal tumour arising from cerebellum?
Medulloblastoma
Retinoblastoma is?
Tumour arising from the retina
What are tumours which arise from sympathetic ganglia?
Neuroblastoma
Ganglioneuroma
Explain something interesting about ganglioneuromas?
Tumour is derived from blast cells but as the tumour grows the neurons actually mature
Tumours which arise in supporting tissue/mesodermal?
Meningiomas
Other mesodermal tumours
Where are meningiomas thought to arise from?
Arachnoid granulations
Where would you find meningiomas commonly?
Adjacent to venous tissues
________ account for 15-20% of intracranial tumours.
Meningiomas
Are meningiomas bad?
Slow-growing and essentially benign
Where can meningiomas occasionally arise?
Spine
True vascular neoplasms are_______, but vascular hamartomas are _________.
- Rare
2. Common
What is a hamartoma?
Noncancerous tumour made of an abnormal mixture of normal tissues and cells from the area in which it grows
Primary microglial and lymphoid tumours are common/rare?
Rare
What tumours are associated with EBV? And what does this make them?
Primary cerebral lymphomas
-Important complication of AIDs
Schwannoma AKA?
Neuroma
What are neuromas derived from?
Schwann cells surrounding axons
Most common neuroma?
Vestibular schwannoma (acoustic neuroma) which arises from CNVIII in the cerebellopontine angle
Where do acoustic neuromas arise from?
CNVIII in the cerebellopontine angle
Symptoms of vestibular schwannoma?
Progressive sensorineural hearing loss
Tinnitus
Vertigo
Tumour is often unilateral so symptoms are too
What tumour commonly has unilateral symptoms?
Vestibular schwannoma/acoustic neuroma
Prognosis of vestibular schwannoma?
Benign
- Tend to grow around adjacent structures
- Irregular surface so can be difficult to remove
What are neurofibromas derived from?
Endoneurium
-Layer of delicate connective tissue around the myelin sheath of each nerve in the PNS
Amount of neurofibromas common?
Can be solitary, or in neurofibromatosis multiple
What sets neurofibromas apart from schwannomas?
Small but significant proportion of neurofibromas undergo transformation to malignant peripheral nerve sheath tumours
Where and derivation of germ cell tumours?
Arise in midline structures
-Derived from embryologically misplaced germ cells
Pituitary gland tumour example?
Adenoma
What is a craniopharyngioma?
Rare type of brain tumour derived from pituitary gland embryonic tissue
General knowledge for direct effects of brain tumours?
Local progressive deterioration in function, signs and symptoms will depend on area of brain affected
Direct effects of frontal lobe lesions: Precentral gyrus?
-Contralateral weakness (part of the body where this occurs depends where tumour is in gyrus- corresponds with motor homunculus)
Where is Broca’s area?
Inferior frontal gyrus
Direct effects of frontal lobe lesions: Broca’s area?
-Expressive dysphasia where patent can still comprehend words but produces faulty sentences
Dysphasia?
How you speak and understand languages
-People with dysphasia might have trouble putting the right words together in a sentence, understanding what others say, reading, and writing
Direct effect of tumour in middle frontal gyrus?
Abnormalities of gaze
Tumour in micturition inhibition centre causes?
Incontinence
Frontal lobe lesions direct effects?
Personality changes, disinhibition and cognitive slowing
Frontal lobe lesions examples?
- Precentral gyrus
- Broca’s area (Inferior frontal gyrus)
- Frontal eye fields (Middle frontal gyrus)
- Micturition inhibition centre
Temporal lobe lesions exmaples?
Auditory cortex and wernickes area (superior temporal gyrus)
Tumour in Auditory cortex can lead to?
Loss of awareness of sound
Tumour in Wernicke’s area?
Damage can lead to receptive dysphagia in which an individual has impaired comprehension and produces jargon (word salad) but fluent speech
Where is Wernicke’s area?
Located in superior temporal gyrus in dominant hemisphere
General direct effects of temporal lobe lesions?
Memory deficits
Contralateral superior quadrantanopia
Tumour in occipital lobe lesions causes?
Visual cortex: visual hallucinations
-Contralateral homonymous hemianopia
Parietal lobe lesions: Postcentral gyrus cause?
Contralateral sensory loss
Part of body will depend on location along gyrus
Parietal lobe lesions can cause?
Contralateral inferior quadrantopia
If dominant lobe affected in parietal lobe lesions?
- Dyscalculia
- Dysgraphia (difficulty writing)
- Finger agnosia (inability to distinguish between and recognise all fingers)
- Left-right disorientation
What is the dominant parietal lobe usually?
Left
Non-dominant parietal lobe lesions causes?
- Neglect
- Dressing apraxia
- Constructional apraxia
What is neglect?
Deficit in awareness of one side of the body
Dressing apraxia?
Inability to dress onseself automatically
Constructional apraxia?
Inability to build, assemble or draw objects
Cerebellum lesions memory tool?
DANISH
DANISH?
Dysdiadochokinesia Ataxia Nystagmus Intention tremor Scanning dysarthria Hypotonia
What is dysdiadochokinesia?
Impairment of rapid alternating movements: quick alternating, pronation supination of hand
Ataxia?
Broad based gait
Nystagmus?
Involuntary, uncontrolled eye movements
Intention tremor?
Tremor that gets worse as you approach end point of guided movement, finger yo nose test can show this
Scanning dysarthria?
Patient speaks slowly with poor articulation of speech
Hypotonia?
Reduced tone
Raised ICP due to mass lesion can present as?
Headache, vomiting and papilloedema
Headache red flags pointing to a tumour?
- Headache worse in morning
- Headache that wakes you up
- Headache worse with coughing or leaning forward
- Headache assoc with vomiting
Why is a red flag headache worse in morning?
Because lying down increases ICP
Why would a headache be assoc with vomiting?
Pressure on medulla
What is papilloedema and cause?
Bilateral optic disc swelling due to raised ICP
Seizures are a common presenting feature of?
Malignant brain tumours
Why seizure = malig brain tumour?
Tumour irritates cortex and disrupts normal electrical pathways
Partial seizures evolving into generalized tonic clonic seizures are characteristic of?
Many hemisphere masses whether benign or malignant
Investigation of choice for brain tumours?
MRI
however CT if MRI not available
Other investigations whne brain tumour found?
Because they are usually mets a chest X-ray should be done
Treatment of low grade astrocytomas?
Removed as it has been shown that these tumours if left have potential to de-differentiate into a high grade malignancy
De-differntiate?
Reverse differentiation and lose specialised charcteristics
Gold standard treatment for glioblastomas?
Surgery, radiotherapy and chemo
Although still poor prognosis
Treatment for oligodendroglial tumours?
Mix of surgery, chemo, radio
Treatment of meningiomas?
Small: watched
Large: Surgery and other
Treatment of vestibular schwannomas?
Often not removed: surgery risks permenant hearing loss:
- Watched
- Hearing aid given
Surgery for vestibular schwannomas difficult because?
Surface so irregular and grow around adjacent structures
