Ch. 6 - Brain tumors

Question 1

Most common CNS tumor associated with NF-1

Answer 1

Optic nerve glioma

Question 2

What is the hallmark tumor of NF-1?

Answer 2

Peripheral neurofibroma

Question 3

What is the hallmark tumor of NF-2?

Answer 3

Bilateral acoustic schwannomas

Question 4

What are the most common cerebral tumors?

Answer 4

Astrocytoma, including GBM (44%)

Metastases (15%)

Meningioma (15%)

Pituitary (8%)

Acoustic neuroma (8%)

Question 5

What does ‘malignant’ refer to in brain tumors?

Answer 5

Aggressive biological characteristics, rather than tendency to metastasize

Question 6

What is the most common astrocytoma in adults?

Answer 6

Glioblastoma multiforme

Question 7

Describe the macroscopic appearance of GBM

Answer 7

Highly vascular margin with necrosis in center with microscopic nests of tumor cells extending outward into brain

Question 8

Do high- or low-grade astrocytomas have a capsule?

Answer 8

Neither, and they have no distinct tumor margins

Question 9

What is the most frequent initial symptom in patients with cerebral astrocytoma?

Answer 9

Seizures (occur in 50-75%); more common if tumor is adjacent to cortex

Question 10

Where are astrocytomas typically found in adults compared to children?

Answer 10

Adults - cerebrum

Children - cerebellum

Question 11

Imaging modality of choice for astrocytomas

Answer 11

MRI is more sensitive than CT (e.g. low-grade gliomas do not enhance with contrast); higher signal intensity on T2-weighted images

Question 12

Identify the lesion

Answer 12

‘Butterfly’ lesion of GBM

Question 13

What is the median survival for GBM after surgery? With adjuvant radiation?

Answer 13

Surgery - 17 weeks

Adjuvant radiation - 37 weeks

Question 14

What is the role of adjuvant radiation following surgery for low-grade astrocytoma?

Answer 14

Not shown to improve survival

Question 15

What is the most common location for oligodendrogliomas?

Answer 15

Nearly all are above the tentorium with most in the cerebral hemispheres (1/2 of these in the frontal lobes)

Question 16

Describe the histologic appearance of oligodendrogliomas

Answer 16

Typically well-differentiated with calcium deposits in 90%

Question 17

What is the most common symptom of oligodendrogliomas?

Answer 17

Epilepsy (in 80%), especially common because they are slow-growing

Question 18

What is the major differential diagnosis for a recurrent cerebral glioma?

Answer 18

Postradiotherapy radiation necrosis (can develop as early as 4 months or as late as 9 years after therapy)

Question 19

What is the most common location for ependymomas?

Answer 19

Infratentorial comparment (2/3 of cases)

Question 20

What is the most common ependymoma location for children? Adults?

Answer 20

Children - infratentorial

Adults - supratentorial

Question 21

What is the macroscopic appearance of ependymomas?

Answer 21

Well-demarcated, nodular, soft and pale; calcification is common

Question 22

What histologic feature is diagnostic for ependymomas?

Answer 22

Perivascular pseudorosettes (eosinophilic halo composed of radiating tapering processes)

Question 23

What is the origin of most tumors in the pineal gland region?

Answer 23

Germinomas

Question 24

What is the classic presentation of a pineal gland tumor?

Answer 24

Endocrine disturbance (e.g. precocious puberty) in a male

Question 25

Parinaud's syndrome

Answer 25

Dorsal midbrain syndrome - limitation of upgaze, convergence paresis with impairment of reaction of pupils to light and accomodation

Question 26

What is the preferred management of pineal gland tumors?

Answer 26

Radiotherapy (very sensitive)

Question 27

What proportion of brain tumors are metastases? From where?

Answer 27

15% (though pathologists report up to 30%) Lung \> breast \> melanoma \> kidney \> GI

Question 28

Metastases occur most often in the distribution of what artery?

Answer 28

Middle cerebral artery

Question 29

Which metastatic tumors are most likely to present with intracerebral hemorrhage?

Answer 29

Melanoma and choriocarcinoma

Question 30

What are the indications for surgical removal of metastases?

Answer 30

Solitary metastasis in an accessible location AND no systemic spread

Question 31

Meningeal carcinomatosis

Answer 31

Widespread, multifocal seeding of the leptomeninges by systemic cancer

Question 32

What has the increase in cerebral lymphoma incidence over the past decade been attributed to?

Answer 32

AIDS and the use of immunosuppressive therapy

Question 33

What is the most common site for primary cerebral lymphoma?

Answer 33

Frontal lobe \>\> temporal \> parietal \> deep nuclei

Question 34

What therapy has the highest clinical response for cerebral lymphoma?

Answer 34

Radiotherapy with up to 80% response rate; however median survival is only improved by 15 months

Question 35

From what sinuses do paranasal sinus tumors most commonly arise?

Answer 35

Ethmoid or maxillary

Question 36

Paranasal sinus tumors are usually of what histologic type?

Answer 36

Squamous cell or adenoid cystic adenocarcinoma

Question 37

What is the usual presentation of paranasal sinus tumors?

Answer 37

Blood-stained or purulent nasal discharge and pain

Question 38

What are chordomas and where do they usually arise?

Answer 38

Rare tumors from notochord cell nests; most common at ends of axial skeleton (basioccipital or sacrococcygeal region)

Question 39

What is the most common form of solid tumor in childhood?

Answer 39

Intracranial tumors

Question 40

What proportion of pediatric brain tumors occur in the posterior fossa and what are the most common types?

Answer 40

60%; cerebellar astrocytoma \> medulloblastoma \> ependymoma

Question 41

What is the usual location of medulloblastoma?

Answer 41

Cerebellar vermis; may be in the lateral cerebellum in older patients

Question 42

What is the prognosis of cerebellar astrocytoma in children?

Answer 42

75% cure rate; most favorable of all intracranial pediatric neoplasms

Question 43

Where do brainstem gliomas most commonly arise?

Answer 43

Pons \> medulla

Question 44

Presentation of brainstem glioma

Answer 44

Multiple bilateral CN palsies, internuclear ophthalmoplegia, apathetic personality changes