BRAIN - Neoplasia Flashcards

Question

Subarachnoid hemorrhage is a common finding in MRI of intravascular lymphoma: true or false?

Answer 1

True Variably sized/shaped intraparenchymal susceptibility artifacts with subarachnoid hemorrhages on histopathology

Answer 2

Tubular areas of susceptibility artifacts corresponding to vascular thrombosis = “susceptibility vessel sign”

Answer 3

Lower body temperature and heart rate Cut-off values of 38.3 °C and 84 bpm allowed discrimination between pituitary macroadenomas and microadenomas.

Answer 4

broad-based meningeal contact obtuse angle with the surface of the adjacent brain may widen the subarachnoid space dural tail sign” on post-contrast images (predictive value of 94% for neoplasia in dogs and cats) vs claw sign in intraax

Answer 5

1. only of strong, 2. meningioma, lymphoma, choroid plexus tumors, and high-grade gliomas

Answer 6

65%, most commonly with hemorrhagic infarcts

Answer 7

cat: benign, slow growing (WHO grade I) dog: begnin 40-57%, atypical (grade II) >40%

Answer 8

atypical and malignant meningiomas displaying significantly lower ADC values compared to benign grade I meningiomas

Answer 9

1. 20% 2. 13-30% (maj in rostral cranial fossa) 3. 50-70% (hyperost in 25% dog) 4. 40%

Answer 10

HS: **T2w isointensity or hypointensity** more extensive **edema** more often had combined **perilesional and distant meningeal enhancement** affecting both the pachymeninges and leptomeninges leptomeningeal enhancement and mass invading into the sulci transtentorial **herniation** and cranial cervical **syringohydromyelia** **ADC values were significantly lower** **lack of blood vessel displacement** on 3D time of flight magnetic resonance angiography M: broad-based appearance **cyst**-like changes **osseous** changes perilesional and **pachymeningeal enhancement**

Answer 11

Third ventricular meningioma > ependymoma > glioma > CPT

Answer 12

Mass **replacing normal choroid plexus** is more likely to be CPT than ependymoma. If normal choroid plexus can be identified separate from a ventricular mass, ependymoma should be considered

Answer 13

CPT: fourth ventricle (50%) followed by the third ventricle (30%) and lateral ventricles (20%) ependymomas: rostral horn of the lateral ventricles

Answer 14

Mild to moderate **edema** has been more frequently reported in choroid plexus carcinomas (70%) compared to choroid plexus papillomas (45%) Choroid plexus carcinoma can display **drop metastases** to other ventricular and subarachnoid locations with a 33% incidence

Answer 15

oligodendroglioma (70% incidence), astrocytoma (20% incidence), and undefined glioma (10% incidence) high-grade tumors are the most prevalent in dogs

Answer 16

male predisposition

Answer 17

**Claw sign** has been determined to be supportive but not pathognomonic for intra-axial localization of canine gliomas with a sensitivity of 85.5% and specificity of 80%

Answer 18

12% of gliomas incorrectly classified as infarcts and as many as 47% of cerebrovascular accidents misdiagnosed as glioma Gliomas: **larger**, more commonly associated with **mass effect and perilesion edema** Gliomas can cause restricted diffusion similar to ischemia; however, **ADC hyperintensity is significantly more common in gliomas**, and acute infarcts may have lower ADC than neoplasia. When diffusion-weighted imaging (DWI) is provided, the rate of misdiagnosis between cerebrovascular accident and glioma is much lower.

Answer 19

Astrocytomas more **T1w isointense or hyperintense** than oligodendrogliomas Oligodendrogliomas in contact with and distort **ventricles** and **less peritumoral edema** maj local oligoden **pirif lobe**

Answer 20

T2w, FLAIR, and T1w sequence signal intensity margins showed similarities to histologic margins for gliomas margins of contrast enhancement alone should not be used for surgical or radiotherapy planning in gliomas

Answer 21

homogeneous T2w hyper, **T2w FLAIR hypo with hyper peripheral rim** uncommon in dogs with gliomas with a low **sensitivity of 16%** when it is present, it has a reported **100% specificity** for the detection of oligodendrogliomas and is significantly associated with **non-enhancing low-grade oligodendrogliomas**

Answer 22

peripheral contrast enhancement cystic region hemmorrhage drop metastasis

Answer 23

Signal abnormalities of the cerebral **white and gray** matter in **at least 3 contiguous cerebral lobes** with involvement of the thalamus and structures in the caudal fossa **minimal to mild contrast enhancement** of the parenchyma and/or meninges MRI can underestimate gliomatosis cerebri lesions and some dogs with gliomatosis cerebri may have a normal MRI

Answer 24

FA value of feline meningiomas have been reported as significantly higher than canine meningiomas

Answer 25

creating DNA damage (causing cells with unrepaired DNA double strand breaks to lose reproductive capacity and undergo a so-called **mitotic death**) inducing **interphase death** (apoptosis, as is the case with lymphocytes)

Answer 26

traditional fractionated RT (FRT; 10–20 daily fractions delivering a total dose of RT ranging from 40 to 50 Gy, Monday–Friday) or stereotactic RT (SRT; 1–5 daily fractions delivering a total dose of RT ranging from 15 to 35 Gy)

Answer 27

gross tumor volume, suspected adjacent microscopic disease or surgically disrupted areas (CTV, or clinical target volume) plus 0.3 to 10 mm of surrounding normal tissue to account for interfraction and intrafraction motion (PTV or planning target volume)

Answer 28

*Peracute* (within 48 hours of treatment; rare): periprocedural **seizures**, **mentation** changes, non-recovery from **anesthesia** *Acute* (1–6 weeks after RT; occasional): owner-reported **somnolence** that often responds to an increase in steroid dose *Early delayed* (1–6 months after RT): **seizures, neurologic decline** that typically responds to treatment with steroids, but can rarely be fatal. This type of adverse effect may be more common with SRT as compared to FRT, since 2 publications report that approximately **one-third of dogs receiving SRT for intracranial meningioma experience neurologic decline** in the first 6 months after treatment. *Late side effects* (>6 months-years after RT; rare): **seizures, mentation changes**, secondary tumor formation

Answer 29

1. 19-25 months 2. 1-2 year, improve with chemo, multiple courses SRT 3. 500 days (carcinoma less than 130) 4. 441 to 952 days (clinical signs related to intracranial disease improved, but peripheral neuropathies did not improve) 5. SRT 329 days, surg + RT 358 to 677 days

Answer 30

Choroid plexus carcinoma Oligodendroglioma

Answer 31

it takes from 5 to 12 months for background EEG rhythms to reach maturity in the dog and cat.

Answer 32

Protocols applying 15-20 fractions of 2-3 Gy to total doses of 45-54 Gy over 4-5 weeks

Answer 33

transient and steroid-responsive deterioration of neurologic status in the period of 3-16 weeks post radiation (early delayed) as described in 31-71.4%. not found to influence survival, but required prolonged corticosteroid treatment for maintenance of quality of life.

Answer 34

Fatal complications (dogs dying within <6months, due to radiation therapy) were still found in 10-14%, a significant proportion of dogs, often paralleled in a severe increase of (uncontrollable) seizure activity. In these patients a direct link was found to the volume parameter of brain at full prescription dose. for strongly hypofractionated protocols it was recommended to keep the normal volume of brain at prescription dose smaller than 1.1cm3, which is usually possible in tumors <3 cm

Answer 35

Median time to progression (TTP) for all cases was **534 days** (95%CI, 310-758), with a significantly shorter TTP in dogs with lesions at the subventricular zone (median TTP, 260 vs. 687 days; p = .049). Tumors at the subventricular zone progressed more often (p = .001), and more likely as CNS-metastasis (52.9% vs. 13.3%, p = .028).

Answer 36

**serum neurofil light chain** (higher struct) serum **CRP** (higher struct)

Answer 37

always enhancement (oft homogenous) often meningeal enhancement infiltration of adjacent extraneural tissue illed defined margin maj focal lesion frequetly affected 2 compartment

Answer 38

lymphomatosus cerebri intravascular lymphomatous meningitis (leptomeningeal)

Answer 39

optic chiasm

Answer 40

T: older, leptomeningeal B: extra-axial CD44 exp: malignant potential

Answer 41

lateral 3rd ventricle vimentine, pseudorosette (palissading around vessel), high mitotic rate

Answer 42

ependymoma, astrocytoma, histocytic sarcoma, meningioma, choroid plexus papilloma/carcinoma, lymphoma + granuloma, abcess, hematoma, congenit malfo

Answer 43

astrocytoma > ependymoma

Answer 44

160 vs 1100 time to progression 70 vs 900

Answer 45

E cadherin (meningothelial origin) maningioma arise from arachnoid layer

Answer 46

lymphosarcoma meningioma osteosarcoma granuloma

Answer 47

RT is 1 possible cause of CMBs formation in dogs. Cerebral microbleeds are most likely to occur in the peritumoral high-dose volume, to be chronic, and to increase in number over time.