Brain Tumors B&B

Question 1

what are the 5 most common tumors in adults, in order?

Answer 1

1. Glioblastoma.
2. Meningioma.
3. Schwannoma.
4. Oligodendroma
5. Pituitary adenoma

Most adult tumors occur above tentorium (supratentorial)

Question 2

what are the 5 most common tumors in children, in order?

Answer 2

1. Astrocytoma.
2. Medulloblastoma.
3. ependymoma
4. hemangioblastoma
5. Craniopharyngioma.

Most child tumors occur below tentorium (infratentorial)

[ASTROnauts BLAST-off, ENDing HuMAN Curiosity]

Question 3

where are most common metastasis to brain? (3)

Answer 3

lung, breast, renal

(also melanoma, colon)

usually multiple lesions on brain MRI (primary usually single)

Question 4

where does the most common primary brain tumor in adults develop? what is the prognosis?

Answer 4

glioblastoma: occurs in cerebral cortex, often crosses corpus callosum (“butterfly glioma”), expresses GFAP

rapidly progressive and malignant, usually fatal within a year (older age = worse prognosis)

Question 5

rapidly progressive and malignant brain tumor which expresses GFAP, affecting adults (50% >65yo)

What is it and where does it occur?

Answer 5

glioblastoma: occurs in cerebral cortex, often crosses corpus callosum (“butterfly glioma”), expresses GFAP

most common primary brain tumor in adults

Question 6

describe the histology finding of glioblastoma

Answer 6

glioblastoma: occurs in cerebral cortex, often crosses corpus callosum (“butterfly glioma”), expresses GFAP

exhibit pseudopallisading: nuclei of tumor cells line up like stakes along edge of necrosis

highly malignant, most common primary brain tumor in adults

Question 7

histology shows central area of necrosis with pseudopallisading tumor cells surrounding. cells are GFAP+

what type of tumor is this

Answer 7

glioblastoma: occurs in cerebral cortex, often crosses corpus callosum (“butterfly glioma”), expresses GFAP

highly malignant, most common primary brain tumor in adults

Question 8

where do meningiomas occur and in whom?

Answer 8

2nd most common primary brain tumor in adults (F>M bc tumor expresses estrogen receptors!)

occurs in convexities of hemispheres near surface of brain, arises from arachnoid cells

“extra-axial” - external to brain, can have dural attachment (“tail”)

Question 9

“extra-axial” brain tumor arising from arachnoid cells

Answer 9

meningioma: 2nd most common primary in adults (F>M), occurs in convexities of hemispheres near surfaces of brain - appears on outside, pushing its way in

can have dural attachment (“tail”)

Question 10

how do meningiomas present?

Answer 10

2nd most common primary in adults (F>M), occurs in convexities of hemispheres near surfaces of brain

usually benign with no metastasis, resectable, often asymptomatic (sometimes cause seizures)

Question 11

Which receptors do meningiomas express and what is the clinical relevance of this?

Answer 11

2nd most common primary in adults (F>M), occurs in convexities of hemispheres near surfaces of brain

express estrogen receptors —> classically affects females more than males

Question 12

what is an important risk factor for meningioma?

Answer 12

prior radiation to head (childhood malignancy) - latency period ~20 years

2nd most common primary in adults (F>M), occurs in convexities of hemispheres near surfaces of brain, arises from arachnoid cells

Question 13

how do parasagittal meningiomas present?

Answer 13

Compress the leg area (medial surface of lobes) similar to an ACA stroke —> lower extremity weakness

2nd most common primary in adults (F>M), occurs in convexities of hemispheres near surfaces of brain, arises from arachnoid cells

Question 14

what does histology of meningioma show?

Answer 14

2nd most common primary in adults (F>M), occurs in convexities of hemispheres near surfaces of brain, arises from arachnoid cells

histology shows psammoma bodies

Question 15

57yo F w PMH of childhood malignancy presents with lower extremity weakness. MRI reveals brain tumor. Biopsy shows psammoma bodies. What type of tumor is this?

Answer 15

meningioma: 2nd most common primary in adults (F>M - expresses estrogen receptor), occurs in convexities of hemispheres near surfaces of brain

parasagittal meningioma can compress leg area, similar to ACA stroke

prior head radiation is risk factor (~20 year latency)

Question 16

what 3 symptoms present with schwannomas?

Answer 16

1. hearing loss
2. tinnitus
3. ataxia

form at cerebellopontine angle, classically located to CN VIII

Question 17

what do schwannomas stain positive for?

Answer 17

S-100 protein

Question 18

schwannomas are closely associated with which disease? how will this present?

Answer 18

neurofibromatosis 2: AD mutation in NF1/NF2

aka MISME: multiple inherited schwannomas, meningiomas, and ependymomas

Question 19

bilateral schwannomas + meningiomas + ependymomas =

Answer 19

neurofibromatosis type 2

Question 20

where do oligodendrogliomas occur, and how do they present?

Answer 20

rare/slow growing tumor of white matter, usually in frontal lobe —> often present with seizures

Question 21

describe the histological appearance of oligodendroglioimas

Answer 21

rare, slow-growing tumor of white matter in frontal lobe (seizures)

cells histologically resemble fried eggs

Question 22

46yo pt presents with new onset seizures. brain MRI reveals tumor of the frontal lobe. biopsy reveals cells with clear cytoplasms, giving the appearance of fried eggs. what is the diagnosis?

Answer 22

oligodendroglioma: rare, slow-growing tumor of white matter

affects adults

Question 23

what is the most common primary brain tumor in children, and where do they occur?

Answer 23

pilocytic astrocytoma: low grade astrocytoma, usually in posterior fossa (cerebellum)

usually benign w/ no metastasis, well-circumcised and cystic/solid, often successfully treated with surgery

GFAP positive + Rosenthal fibers

Question 24

for what do pilocytic astrocytomas stain positive?

Answer 24

pilocytic astrocytoma: low grade astrocytoma, usually in posterior fossa (cerebellum)

usually benign w/ no metastasis, well-circumcised and cystic/solid, often successfully treated with surgery

GFAP positive + Rosenthal fibers… this makes sense because astrocytes express GFAP, and Rosenthal fibers are seen whenever there is gliosis

Question 25

child presents with tumor in cerebellum which stains GFAP+, and biopsy shows Rosenthal fibers. what is the dx?

Answer 25

pilocytic astrocytoma: low grade astrocytoma, usually in posterior fossa (cerebellum)

usually benign w/ no metastasis, well-circumcised and cystic/solid, often successfully treated with surgery

Question 26

where do medulloblastomas occur, and how do they present (and in whom)?

Answer 26

rare, highly malignant primary brain tumor affecting children - this makes sense because they are type of primitive neuroectodermal tumor (PNET)

usually occur in midline cerebellum —> truncal ataxia

Question 27

7yo pt presents with truncal ataxia and is found to have a tumor in the midline of their cerebellum. biopsy shows primitive neural cells. what is the diagnosis and prognosis?

Answer 27

medulloblastoma: rare, highly malignant primary brain tumor affecting children, type of primitive neuroectodermal tumor (PNET)

however, can be treated with surgery/radiation/chemo, and 75% of children survive to adulthood - but many with complications of treatment

Question 28

what are 2 complications of medulloblastomas?

Answer 28

rare, highly malignant primary brain tumor affecting children, usually occur in midline cerebellum —> truncal ataxia

1. can compress 4th ventricle —> hydrocephalus
2. can spread to CSF —> ”drop metastasis” causing nodules in dura of spinal cord

Question 29

what occurs as a result of “drop metastasis” of medulloblastoma?

Answer 29

rare, highly malignant primary brain tumor affecting children, usually occur in midline cerebellum (truncal ataxia)

can spread to CSF, causing nodules in dura of spinal cord (“drop metastasis”) - tend to occur in lower spinal cord/cauda equina —> back pain, focal neuro lesions can occur

Question 30

what is the characteristic pathology finding of medulloblastomas?

Answer 30

rare, highly malignant primary brain tumor affecting children, usually occur in midline cerebellum (truncal ataxia)

histology shows Homer-Wrights rosettes: tumor cells form circles with space in middle that resemble church stain glass rosettes

Question 31

where do ependymomas develop, and in whom?

Answer 31

ependyma = epithelium-like lining of ventricles

occur in children, develop in brain and spinal cord, often found in 4th ventricle —> hydrocephalus

Question 32

what is the characteristic histology finding of ependymomas?

Answer 32

occur in children, develop in brain/ spinal cord, often found in 4th ventricle (hydrocephalus)

histology shows pseudorosettes: tumor cells surround central clearing, but core is blood vessel (not totally clear as in rosettes of medulloblastomas)

Question 33

child presents with hydrocephalus, and it is discovered they have a tumor in their 4th ventricle. biopsy shows tumor cells arranged around a blood vessel core. what is the dx?

Answer 33

ependymoma: occur in children, develop in brain/ spinal cord, often found in 4th ventricle

histology shows pseudorosettes: tumor cells surround central clearing, but core is blood vessel (not totally clear as in rosettes of medulloblastomas)

Question 34

with what genetic disease are hemangioblastomas associated? in whom do they occur?

Answer 34

hemangioblastomas: very rare, slow growing CNS tumors that are well-circumscribed and highly vascular, occur in children

occur with von Hippel Lindau syndrome: AD mutation in tumor suppressor gene —> lots of tumors throughout body (hemangioblastomas, retinal angiomas, renal cell carcinomas, pheochromocytomas)

Question 35

what do hemangioblastomas secrete? what is the clinical effect of this?

Answer 35

hemangioblastomas: very rare, slow growing CNS tumors that are well-circumscribed and highly vascular, occur with von Hippel Lindau syndrome

can produce EPO —> polycythemia

Question 36

pt is 9yo F found to have tumor in their cerebellum. Imaging shows a well-circumscribed, highly vascular tumor. Serum studies reveal polycythemia. What is the dx?

Answer 36

hemangioblastoma: very rare, slow growing CNS tumors that are well-circumscribed and highly vascular, occur with von Hippel Lindau syndrome

can produce EPO —> polycythemia

Question 37

what are the symptoms (3) of craniopharyngiomas? in whom do they occur?

Answer 37

rare, benign, suprasellar (above pituitary to base of 3rd ventricle) tumors, occur in ages 10-14

symptoms are from compression —> hormonal imbalance (pituitary), behavioral change (frontal lobe), bitemporal hemianopsia (optic chiasm)

Question 38

where do craniopharyngiomas develop, and from what are they derived?

Answer 38

occur in children (10-14), derived from remnants of Rathke’s pouch: invagination of ectoderm that protrudes from roof of mouth (also forms anterior pituitary)

develop above sella turcica (suprasellar - anywhere from pituitary gland to base of 3rd ventricle)

benign, symptoms from compression

Question 39

Pt is 11yo M taken to their GP by their parent due to concerns of behavioral changes and problems with vision. An MRI is performed which shows a calcified and cystic tumor in the sella turcica. A biopsy is taken, which shows epithelial cells. What is the dx?

Answer 39

craniopharyngioma: derived from remnants of Rathke’s pouch (invagination of ectoderm, also forms anterior pituitary)

develop above sella turcica (suprasellar - anywhere from pituitary gland to base of 3rd ventricle)

benign, symptoms from compression (optic chiasm, frontal lobe, pituitary)

Question 40

what symptoms are caused by mass effect of pineal tumors?

Answer 40

rare germ cell or parenchymal tumors, occur in children

cause compression of pretectal area of midbrain —> Parinaud syndrome: paralysis of upward gazes + pseudo-Argyll-Robertson pupil (react to accommodation but not light)

can also compress cerebral aqueduct —> hydrocephalus, papilledema

Question 41

how does Parinaud syndrome present? what type of tumor can cause it?

Answer 41

Parinaud syndrome: paralysis of upward gazes + pseudo-Argyll-Robertson pupil (react to accommodation but not light)

can be caused by pineal tumors: rare germ cell or parenchymal tumors, occur in children, cause compression of pretectal area of midbrain

Question 42

Pt is 8yo F presenting to neurologist after GP determined they have hydrocephalus and papilledema. On neuro examination, you find paralysis of upward gaze. Further, pupils respond to accommodation, but not light. What area of the brain is compressed by this tumor? Of what cells is this tumor made?

Answer 42

pineal tumor: rare germ cell or parenchymal tumors, occur in children

cause compression of pretectal area of midbrain —> Parinaud syndrome: paralysis of upward gazes + pseudo-Argyll-Robertson pupil (react to accommodation but not light)

can also compress cerebral aqueduct —> hydrocephalus, papilledema

Question 43

describe the classic radiologic picture of a glioblastoma. what genetics are often implicated?

Answer 43

radiologic picture shows cerebral rim/ring-enhancing lesion

genetics frequently involve amplification of receptor tyrosine kinases (EGFR, MET, PDGFR)

Question 44

what genetics are implicated in oligodendrogliomas?

Answer 44

co-deletion of 1p and 19q

Question 45

what features would be present in a biopsy of oligodendroglioma? (3)

Answer 45

1. “fried egg” nuclei
2. “chickenwire” vasculature
3. calcifications

Question 46

what does histology of schwannomas show? (2)

Answer 46

1. hyper or hypo cellular areas (Antoni areas: appear hyper/hypo pigmented)
2. Verocay bodies: nuclei lining up together

Question 47

what do medulloblastomas stain positive for?

Answer 47

synaptophysin positive

Malignant tumor of primitive neurons that primarily affects young children, occur in cerebellar/posterior fossa

Question 48

where do brain metastasis usually develop?

Answer 48

most commonly from lung, breast, renal, melanoma, colon

typically develop at grey-white junction as well-circumscribed masses

glandular characteristic of metastasis matches histology in primary site

Question 49

what does histology of craniopharyngiomas show?

Answer 49

Tumor arising in sellar region (similar to Pit
adenoma)
• Derived from remnants
of Rathke pouch
• Histological features: Squamous epithelium

Question 50

what is the role of the neurofibromin (FN1) gene that is mutated in neurofibromatosis 1?

Answer 50

NF1 negatively regulates Ras oncoprotein

mutation —> Tumors:
• Neurofibromas
• Café au lait spots
• Optic gliomas
• Pheochromocytomas
• Malignant peripheral nerve sheath tumor

Question 51

what is the role of the NF2 gene which is mutated in neurofibromatosis 2?

Answer 51

NF2 gene (ch. 22) encodes Merlin: links pro-proliferation signals at membrane with underlying actin cytoskeleton

CNS Tumors:
• Bilateral vestibular schwannoma is hallmark of the syndrome
• Meningioma
• Ependymoma