BMB 2 - CNS Neoplasms; Paraneoplastic & Autoimmune Encephalitis

Question 1

Metastatic malignancies to the brain are ____x more likely than primary malignancies.

Answer 1

Metastatic malignancies to the brain are 10 x more likely than primary malignancies.

Question 2

20% of metastases to the adult brain come from what organ system?

Answer 2

The lungs

Question 3

What are the four most common origin sites for metastases ending up in the adult brain?

Answer 3

Lung > melanoma > breast > renal cell carcinomas

(>> colorectal)

Question 4

What are the three most common origin sites for metastases ending up in the pediatric brain?

Answer 4

Sarcomas

Neuroblastomas

Germ cell tumors

Question 5

What are the most common origin sites for hemorrhagic metastases ending up in the adult brain?

Answer 5

Melanoma,

renal,

thyroid,

choriocarcinoma

Question 6

What is the most common type of primary brain cancer?

Answer 6

Diffusely infiltrating gliomas

(e.g. glioblastoma multiforme)

Question 7

Name some of the various S/Sy sometimes seen in patients with primary brain tumors?

Answer 7

Weakness and numbness

Aphasia

Seizures

Ataxia and gait impairment

Headaches

Brainstem symptoms

Blindness

Question 8

Primary brain tumors are generally more associated with epilepsy in ________er patient populations and due to the less common, _______-grade gliomas.

Answer 8

Primary brain tumors are generally more associated with epilepsy in younger patient populations and due to the less common, high-grade gliomas.

Question 9

Why are high-grade gliomas more likely to result in epilepsy than low-grade?

Answer 9

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)

Question 10

Brain metastases do not typically cause seizures; they are only more likely to cause them in what circumstances?

Answer 10

Unless (1) the cortex is involved or (2) the metastases are hemorrhagic

Question 11

Brain metastases are widely associated with _________ edema and ____toxicity.

Answer 11

Brain metastases are widely associated with vasogenic edema and cytotoxicity.

Question 12

True/False.

MRI is the main imaging technique used in identifying brain metastases.

Answer 12

True.

Question 13

How do brain metastases typically present on MRI?

Answer 13

Multiple, well-circumscribed lesions at the gray-white junction

Question 14

The large majority (80%) of brain metastases are in what location?

Options: cerebrum, cerebellum, or brainstem

Answer 14

Cerebrum

Question 15

What would be your first step in working up the source of a patient’s brain metastases?

Answer 15

CT scan of the chest/abdomen/pelvis

Question 16

What are the three options for radiation of brain metastases?

Answer 16

1. Whole brain radiation
2. Hippocampal-avoidant radiation
3. Stereotactic radiosurgery

Question 17

What term refers to the condition in which a solid tumor (typically lung, melanoma, or breast tumors) diffusely spreads to the leptomeninges?

Answer 17

Leptomeningeal carcinomatosis

Question 18

A patient with untreated leptomeningeal carcinomatosis can expect to live how long?

And with treated leptomeningeal carcinomatosis?

Answer 18

4 weeks

4 months

(rapidly fatal)

Question 19

Give the four names for the four grades of astrocytoma:

Answer 19

Grade 1 — Pilocytic

Grade 2 — Diffuse​

Grade 3 — Anaplastic​

Grade 4 — Glioblastoma​

Question 20

Glioblastoma multiforme is actually a very aggressive form of __________oma.

Answer 20

Glioblastoma multiforme is actually a very aggressive form of astrocytoma.

Question 21

Are glioblastomas benign or malignant?

Answer 21

Malignant

Question 22

What are the features of oligodendroglioma growth and IDH genetics?

Answer 22

Slow-growing with calcification;

1p/19q codeletion

Question 23

Which primary brain tumor is typically found in either the spinal cord, brainstem, or thalamus and involves histone mutations?

Answer 23

Diffuse midline glioma

(associated with K27M and G34R mutations)

Question 24

Which primary brain tumor is associated with HIV and EBV?

Answer 24

Primary CNS lymphoma

Question 25

What is the most common pediatric malignancy of the brain?

Answer 25

Medulloblastoma

(slight predominance for males)

Question 26

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.)?

Answer 26

Medulloblastoma

Question 27

What tumor type is described as a “sausage shaped” tumor in the conus medullaris?

Answer 27

Ependymoma

Question 28

What is the characteristic histology of an ependyoma?

Answer 28

Perivascular psuedorossettes

Question 29

Which size of pituitary adenoma is typically non-secreting?

Answer 29

Macroadenomas

Question 30

Pituitary adenomas can either be pituitary macroadenomas (> ___ cm) or pituitary microadenomas (< ___ cm).

Answer 30

Pituitary adenomas can either be pituitary macroadenomas (> 1 cm) or pituitary microadenomas (< 1 cm).

Question 31

Mengiomas arise from what tissue layer(s)?

Answer 31

The arachnoid mater

(and can thus arise anywhere in the CNS where there’s arachnoid)

Question 32

How does a meningioma appear on imaging?

Answer 32

An extra-axial mass with dural tail

Question 33

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)

Answer 33

True.

Question 34

Name a few malignancies associated with paraneoplastic subacute cerebellar degeneration.

Answer 34

Gynecological (ovarian, endometrial, and breast cancers)

Small cell carcinoma of the lung

Hodgkin’s lymphoma

Question 35

What are the presenting features of paraneoplastic subacute cerebellar degeneration?

Answer 35

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)

Question 36

Which auto-antibodies are associated with paraneoplastic subacute cerebellar degeneration in patients with breast cancer?

Answer 36

Anti-Yo antibodies; anti-Ri antibodies

Question 37

Which auto-antibodies are associated with paraneoplastic subacute cerebellar degeneration in patients with small cell lung cancer?

Answer 37

Anti-Hu antibodies

Question 38

Which auto-antibodies are associated with paraneoplastic subacute cerebellar degeneration in patients with neuroblastoma?

Answer 38

Anti-Hu antibodies

Question 39

A patient with breast cancer develops opsoclonus and ataxia. She likely has anti-____ antibodies targeting her _____________.

Answer 39

A patient with breast cancer develops opsoclonus and ataxia. She likely has anti-Ri antibodies targeting her cerebellum.

Question 40

An infant presenting with opsoclonus-myoclonus syndrome likely has anti-_____ antibodies and an underlying ____________.

Answer 40

A baby presenting with opsoclonus-myoclonus syndrome likely has anti-_Ri (Anna 2)_ antibodies and an underlying neuroblastoma.

Question 41

What is the colloquial term for opsolonus-myoclonus syndrome?

Answer 41

‘Dancing eyes, dancing feet’ syndrome

Question 42

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?

Answer 42

NMDA-receptors

(There were present on the teratoma; there is now cross-reactivity with the CNS.)

Question 43

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?

Answer 43

LGI1

(leading to LGI1-associated encephalitis)

Question 44

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?

Answer 44

Pembrolizumab

Question 45

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)?

Answer 45

PD-1 inhibitors and PD-L1 inhibitors

Question 46

A 10 year old presents with chorea one week after an upper respiratory infection.

What do you suspect?

Answer 46

Autoimmune issue of the basal ganglia following a S. pyogenes infection

Question 47

A 22-year-old presets with a new onset movement disorder, psychoses, slow writhing movements, and dystonia.

What do you suspect?

Answer 47

Anti-NMDA-receptor antibodies

Question 48

A 35-year-old presents with a new-onset movement disorder, altered mental status, and abnormal liver function tests.

What do you suspect?

Answer 48

Wilson’s disease

(hepatolenticular degeneration)

Question 49

Following treatment for Hashimoto’s thyroiditis, a female patient presents with neuropsychiatric symptoms and seizures, anti-TPO/thyroglobulin antibodies.

How do you treat her?

Answer 49

Steroids

(Hashimoto’s encephalitis, aka steroid-responsive encephalopathy)