BMB 2 - CNS Neoplasms; Paraneoplastic & Autoimmune Encephalitis Flashcards
Metastatic malignancies to the brain are ____x more likely than primary malignancies.
Metastatic malignancies to the brain are 10 x more likely than primary malignancies.
20% of metastases to the adult brain come from what organ system?
The lungs
What are the four most common origin sites for metastases ending up in the adult brain?
Lung > melanoma > breast > renal cell carcinomas
(>> colorectal)
What are the three most common origin sites for metastases ending up in the pediatric brain?
Sarcomas
Neuroblastomas
Germ cell tumors
What are the most common origin sites for hemorrhagic metastases ending up in the adult brain?
Melanoma,
renal,
thyroid,
choriocarcinoma
What is the most common type of primary brain cancer?
Diffusely infiltrating gliomas
(e.g. glioblastoma multiforme)
Name some of the various S/Sy sometimes seen in patients with primary brain tumors?
Weakness and numbness
Aphasia
Seizures
Ataxia and gait impairment
Headaches
Brainstem symptoms
Blindness
Primary brain tumors are generally more associated with epilepsy in ________er patient populations and due to the less common, _______-grade gliomas.
Primary brain tumors are generally more associated with epilepsy in younger patient populations and due to the less common, high-grade gliomas.
Why are high-grade gliomas more likely to result in epilepsy than low-grade?
Due to an IDH 1/2 mutation which results in production of 2-hydroxyglutarate, which is both cytotoxic and stimulatory
(i.e. they produce glutamate, which is excitatory)
Brain metastases do not typically cause seizures; they are only more likely to cause them in what circumstances?
Unless (1) the cortex is involved or (2) the metastases are hemorrhagic
Brain metastases are widely associated with _________ edema and ____toxicity.
Brain metastases are widely associated with vasogenic edema and cytotoxicity.
True/False.
MRI is the main imaging technique used in identifying brain metastases.
True.
How do brain metastases typically present on MRI?
Multiple, well-circumscribed lesions at the gray-white junction
The large majority (80%) of brain metastases are in what location?
Options: cerebrum, cerebellum, or brainstem
Cerebrum
What would be your first step in working up the source of a patient’s brain metastases?
CT scan of the chest/abdomen/pelvis
What are the three options for radiation of brain metastases?
- Whole brain radiation
- Hippocampal-avoidant radiation
- Stereotactic radiosurgery
What term refers to the condition in which a solid tumor (typically lung, melanoma, or breast tumors) diffusely spreads to the leptomeninges?
Leptomeningeal carcinomatosis
A patient with untreated leptomeningeal carcinomatosis can expect to live how long?
And with treated leptomeningeal carcinomatosis?
4 weeks
4 months
(rapidly fatal)
Give the four names for the four grades of astrocytoma:
Grade 1 — Pilocytic
Grade 2 — Diffuse
Grade 3 — Anaplastic
Grade 4 — Glioblastoma
Glioblastoma multiforme is actually a very aggressive form of __________oma.
Glioblastoma multiforme is actually a very aggressive form of astrocytoma.
Are glioblastomas benign or malignant?
Malignant
What are the features of oligodendroglioma growth and IDH genetics?
Slow-growing with calcification;
1p/19q codeletion
Which primary brain tumor is typically found in either the spinal cord, brainstem, or thalamus and involves histone mutations?
Diffuse midline glioma
(associated with K27M and G34R mutations)
Which primary brain tumor is associated with HIV and EBV?
Primary CNS lymphoma
What is the most common pediatric malignancy of the brain?
Medulloblastoma
(slight predominance for males)
What primary brain tumor is seen in children and is associated with a variety of familial cancer predisposition syndromes (e.g. Li-Fraumeni, Turcot, Gorlin, etc.)?
Medulloblastoma
What tumor type is described as a “sausage shaped” tumor in the conus medullaris?
Ependymoma
What is the characteristic histology of an ependyoma?
Perivascular psuedorossettes
Which size of pituitary adenoma is typically non-secreting?
Macroadenomas
Pituitary adenomas can either be pituitary macroadenomas (> ___ cm) or pituitary microadenomas (< ___ cm).
Pituitary adenomas can either be pituitary macroadenomas (> 1 cm) or pituitary microadenomas (< 1 cm).
Mengiomas arise from what tissue layer(s)?
The arachnoid mater
(and can thus arise anywhere in the CNS where there’s arachnoid)
How does a meningioma appear on imaging?
An extra-axial mass with dural tail
True/False.
~80% of meningiomas are benign (grade I; surgery only);
~20% are atypical (grade II; surgery and maybe radiation);
<2% are malignant (grade III; surgery and radiation)
True.
Name a few malignancies associated with paraneoplastic subacute cerebellar degeneration.
Gynecological (ovarian, endometrial, and breast cancers)
Small cell carcinoma of the lung
Hodgkin’s lymphoma
What are the presenting features of paraneoplastic subacute cerebellar degeneration?
Progressive cerebellar dysfunction over a period of several weeks in a patient with an underlying malignancy;
dysarthria, vertigo, gait instability, limb and ocular ataxia, nystagmus, diplopia
(results due to loss of Purkinje fibers)
Which auto-antibodies are associated with paraneoplastic subacute cerebellar degeneration in patients with breast cancer?
Anti-Yo antibodies; anti-Ri antibodies
Which auto-antibodies are associated with paraneoplastic subacute cerebellar degeneration in patients with small cell lung cancer?
Anti-Hu antibodies
Which auto-antibodies are associated with paraneoplastic subacute cerebellar degeneration in patients with neuroblastoma?
Anti-Hu antibodies
A patient with breast cancer develops opsoclonus and ataxia. She likely has anti-____ antibodies targeting her _____________.
A patient with breast cancer develops opsoclonus and ataxia. She likely has anti-Ri antibodies targeting her cerebellum.
An infant presenting with opsoclonus-myoclonus syndrome likely has anti-_____ antibodies and an underlying ____________.
A baby presenting with opsoclonus-myoclonus syndrome likely has anti-_Ri (Anna 2)_ antibodies and an underlying neuroblastoma.
What is the colloquial term for opsolonus-myoclonus syndrome?
‘Dancing eyes, dancing feet’ syndrome
A patient with a previous ovarian teratoma presents with S/Sy of encephalitis. MRI shows hyperintensities in her temporal lobes. You suspect her body may have developed antibodies against what?
NMDA-receptors
(There were present on the teratoma; there is now cross-reactivity with the CNS.)
A patient with a previous thymoma presents with S/Sy of encephalitis. MRI shows hyperintensities in his medial temporal lobes and basal ganglia. You suspect his body may have developed antibodies against what?
LGI1
(leading to LGI1-associated encephalitis)
What medication used in managing thymomas is associated with severe fatigue, acute kidney injury, respiratory failure, sepsis, and multiple organ failure due to myasthenic crisis?
Pembrolizumab
What medication type is useful in treating some malignancies by ‘taking the foot off the break’ of T cells (via a mechanism of action in which an inhibitory signal is purposefully blocked)?
PD-1 inhibitors and PD-L1 inhibitors
A 10 year old presents with chorea one week after an upper respiratory infection.
What do you suspect?
Autoimmune issue of the basal ganglia following a S. pyogenes infection
A 22-year-old presets with a new onset movement disorder, psychoses, slow writhing movements, and dystonia.
What do you suspect?
Anti-NMDA-receptor antibodies
A 35-year-old presents with a new-onset movement disorder, altered mental status, and abnormal liver function tests.
What do you suspect?
Wilson’s disease
(hepatolenticular degeneration)
Following treatment for Hashimoto’s thyroiditis, a female patient presents with neuropsychiatric symptoms and seizures, anti-TPO/thyroglobulin antibodies.
How do you treat her?
Steroids
(Hashimoto’s encephalitis, aka steroid-responsive encephalopathy)
