Ch. 6 - Brain tumors Flashcards Preview

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Flashcards in Ch. 6 - Brain tumors Deck (44)
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1
Q

Most common CNS tumor associated with NF-1

A

Optic nerve glioma

2
Q

What is the hallmark tumor of NF-1?

A

Peripheral neurofibroma

3
Q

What is the hallmark tumor of NF-2?

A

Bilateral acoustic schwannomas

4
Q

What are the most common cerebral tumors?

A

Astrocytoma, including GBM (44%)

Metastases (15%)

Meningioma (15%)

Pituitary (8%)

Acoustic neuroma (8%)

5
Q

What does ‘malignant’ refer to in brain tumors?

A

Aggressive biological characteristics, rather than tendency to metastasize

6
Q

What is the most common astrocytoma in adults?

A

Glioblastoma multiforme

7
Q

Describe the macroscopic appearance of GBM

A

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

8
Q

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

A

Neither, and they have no distinct tumor margins

9
Q

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

A

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

10
Q

Where are astrocytomas typically found in adults compared to children?

A

Adults - cerebrum

Children - cerebellum

11
Q

Imaging modality of choice for astrocytomas

A

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

12
Q

Identify the lesion

A

‘Butterfly’ lesion of GBM

13
Q

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

A

Surgery - 17 weeks

Adjuvant radiation - 37 weeks

14
Q

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

A

Not shown to improve survival

15
Q

What is the most common location for oligodendrogliomas?

A

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

16
Q

Describe the histologic appearance of oligodendrogliomas

A

Typically well-differentiated with calcium deposits in 90%

17
Q

What is the most common symptom of oligodendrogliomas?

A

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

18
Q

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

A

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

19
Q

What is the most common location for ependymomas?

A

Infratentorial comparment (2/3 of cases)

20
Q

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

A

Children - infratentorial

Adults - supratentorial

21
Q

What is the macroscopic appearance of ependymomas?

A

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

22
Q

What histologic feature is diagnostic for ependymomas?

A

Perivascular pseudorosettes (eosinophilic halo composed of radiating tapering processes)

23
Q

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

A

Germinomas

24
Q

What is the classic presentation of a pineal gland tumor?

A

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

25
Q

Parinaud’s syndrome

A

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

26
Q

What is the preferred management of pineal gland tumors?

A

Radiotherapy (very sensitive)

27
Q

What proportion of brain tumors are metastases? From where?

A

15% (though pathologists report up to 30%)

Lung > breast > melanoma > kidney > GI

28
Q

Metastases occur most often in the distribution of what artery?

A

Middle cerebral artery

29
Q

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

A

Melanoma and choriocarcinoma

30
Q

What are the indications for surgical removal of metastases?

A

Solitary metastasis in an accessible location AND no systemic spread

31
Q

Meningeal carcinomatosis

A

Widespread, multifocal seeding of the leptomeninges by systemic cancer

32
Q

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

A

AIDS and the use of immunosuppressive therapy

33
Q

What is the most common site for primary cerebral lymphoma?

A

Frontal lobe >> temporal > parietal > deep nuclei

34
Q

What therapy has the highest clinical response for cerebral lymphoma?

A

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

35
Q

From what sinuses do paranasal sinus tumors most commonly arise?

A

Ethmoid or maxillary

36
Q

Paranasal sinus tumors are usually of what histologic type?

A

Squamous cell or adenoid cystic adenocarcinoma

37
Q

What is the usual presentation of paranasal sinus tumors?

A

Blood-stained or purulent nasal discharge and pain

38
Q

What are chordomas and where do they usually arise?

A

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

39
Q

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

A

Intracranial tumors

40
Q

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

A

60%; cerebellar astrocytoma > medulloblastoma > ependymoma

41
Q

What is the usual location of medulloblastoma?

A

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

42
Q

What is the prognosis of cerebellar astrocytoma in children?

A

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

43
Q

Where do brainstem gliomas most commonly arise?

A

Pons > medulla

44
Q

Presentation of brainstem glioma

A

Multiple bilateral CN palsies, internuclear ophthalmoplegia, apathetic personality changes