BRAIN - Neoplasia Flashcards
Which tumor of the cranial fossa can be suspected in a young dog?
Germ cell tumors
What are the most common clinical signs associated with pituitary apoplexy in dogs?
Galli, 2022:
Behavioural abnormalities (11/19)
Obtundation (7/19)
Vestibular syndrome (7/19)
Epileptic seizures (6/19)
Woelfel, 2023:
Gait or posture changes (85%)
Mentation changes (69%)
Cranial neuropathies (65%)
GI dysfunction (54%)
Cervical/head hyperpathia (46%)
Hyperthermia (31%)
What is the influence of macroadenoma on vital parameters? Which cut-offs can be used to differentiate from microadenoma?
Lower body temperature (cut-off: 38,3°C)
Lower heart rate (cut-off: 84 bpm)
Benchekroun, 2017
In glioma, lesions tend to be hyperintense on ADC maps while infarcts tend to be hypointense: true or false?
True
What are the 2 most tumor types associated with CSF drop metastasis?
Choroid plexus carcinoma
Oligodendroglioma
Which breed is not predisposed to glioma?
English Bulldog
Pug
Boxer
French Bulldog
Boston terrier
Pug
Succint prednisolone tapering (40d vs 100) after radiation therapy has a significative effect on
1/ Rates at which corticosteroids had to be reinstituted later
2/ Adverse effect rates
No
What are the 2 most common cause of VPS obstruction?
Choroid plexus
Glial tissue
Germ cell neoplasm are commonly found: where, when, which breed?
Middle cranial fossa
Young (6m-3y)
Doberman
Breeds overrepresented for CNS histiocytic sarcoma?
Burmese Mountain Dog
Golden Retriever
Rottweiler (disseminated exclusively)
Corgi Welsh terrier (primary > disseminated)
Shetland Sheepdogs (primary > disseminated)
Labrador Retriever?
TNCC and protein: primary > disseminated
In all groups: increased neutrophil to lymphocyte ratio
Prevalence of brain tumors: primary (2%), secondary (3%)
What are the most common perioperative and postoperative complications following craniotomy in dogs and cats?
Perioperative complications
Hypotension (23%)
Anemia (16%)
Postoperative complications
Neurologic deficits
Seizures
Anemia
Aspiration pneumonia
long term complic: seizure, neuro deficit
complication 30% within 24h, 50% 1-10 days post op
What are the 1H-MRS hallmarks of neoplasia?
Increased NAA, Cr, Glx
Decreased Cho (choline)
In intravascular lymphoma in dogs, contrast enhancement is seen in which of the following: ischemic areas, parenchymal lesions and/or meninges?
Parenchymal lesions and meninges
Differential for supprasellar neoplasia in dog.
Macroadenoma
Meningioma
Lymphoma
Granular cell tumor
Gliomatosis cerebri
Craniopharyngioma
Germ cell tumor
Metastasis
True or false? In dogs with pituitary macroadenoma that undergo radiation therapy, the presence of pituitary dependant hypercortisolism is a negative prognostic indicator.
False
“No statistical difference in survival was identified between the PDH and non-PDH groups, and longer survival was associated with higher Gy delivered.”
Mannitol does not affect plasma electrolytes levels: true or false?
False
Transient plasma sodium and chloride concentrations decreased
What are the MRI features associated with high grade oligodendroglioma in dogs?
Features only associated with grade III
Moderate to marked contrast enhancement
Ring pattern
Features strongly associated with grade III
Cystic structures
GRE signal voids
Necrosis
In which dog breed, a familial inheritance pattern has been associated with development of gliomatosis cerebri:
Bearded collies
What are the preferential location for intracranial hemangiosarcomas? Vertebral? Epidural? Intramedullary?
Intracranial: telencephalon (intra-axial, multiple)
Vertebral: thoracic vertebral canal & paraspinal tissues(polyostotic, aggressive)
Epidural: thoracolumbar (single, well-marginated)
Intramedullary: cervical (metastatic, with intracranial lesions)
In cats, choroid plexus tumours are less frequent than ependymoma?
True
What is the death rate associated with ventriculoperitoneal shunt placement in dogs and cats?
14%
What is the timeframe where complications after ventriculoperitoneal shunt placement are the most likely?
6 months
What are the main complications associated with ventriculoperitoneal shunt placement in dogs and cats?
Dogs: obstruction (10%), pain (6%), infection (4%), disconnection (4%), excessive shunting (3%), kinking (2%)
Cats: coiling of the shunt in the SC tissue (15%); kinking (8%), obstruction (8%).
What are the 2 methods to assess BBB leakage in brain tumor?
- Dynamic contrast-enhanced (DCE): T1-weighted perfusion MRI (DCE-MRI) allowing quantitative assessment of tissue perfusion over time and BBB dysfunction
- Subtraction enhancement analysis (SEA): semiquantitative method comparing enhancement in each brain voxel in MR images obtained before and after intravenous contrast administration
Subarachnoid hemorrhage is a common finding in MRI of intravascular lymphoma: true or false?
True
Variably sized/shaped intraparenchymal susceptibility artifacts with subarachnoid hemorrhages on histopathology
In intravascular lymphoma in dogs, what is the appearance of susceptibility vessel sign in SWI?
Tubular areas of susceptibility artifacts corresponding to vascular thrombosis
= “susceptibility vessel sign”
Dogs with macroadenoma have
1/ lower/higher body temperature
2/ lower/higher heart rate
Lower body temperature and heart rate
Cut-off values of 38.3 °C and 84 bpm allowed discrimination between pituitary macroadenomas and microadenomas.
Cat or dog?
Has sympathetic innervation of third eyelid
cat
characteristic of extra-axial mass
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
- presence contrast enhancement predictive value for neoplasia
- strong enhancing tumors
- only of strong,
- meningioma, lymphoma, choroid plexus tumors, and high-grade gliomas
% of cerebrovascular event with mass effect on MRI
65%, most commonly with hemorrhagic infarcts
maj meningioma type in cat/dog
cat: benign, slow growing (WHO grade I)
dog: begnin 40-57%, atypical (grade II) >40%
diff meningioma type with ADC
atypical and malignant meningiomas displaying significantly lower ADC values compared to benign grade I meningiomas
% meningioma
1. with T1 precontrast hyperintensity
2. with cystic component
3. associated with a dural tail sign and calvarial hyperostosis
4. Intratumoral magnetic susceptibility artifact consistent with hemorrhage or mineralization
- 20%
- 13-30% (maj in rostral cranial fossa)
- 50-70% (hyperost in 25% dog)
- 40%
diff meningioma/histocytic sarcoma
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
most common intraventricular tumor in cats
Third ventricular meningioma > ependymoma > glioma > CPT
diff ependymoma/choroid plexus tumor
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
localisation of choiroid plexus tumor/ependymoma
CPT: fourth ventricle (50%) followed by the third ventricle (30%) and lateral ventricles (20%)
ependymomas: rostral horn of the lateral ventricles
diff choroid plexus carcinoma/papilloma
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
main glioma subtypes in dog
oligodendroglioma (70% incidence), astrocytoma (20% incidence), and undefined glioma (10% incidence)
high-grade tumors are the most prevalent in dogs
sex predilection in canine gliomas
male predisposition
sign to differenciate peripherally located contrast-enhancing gliomas from meningioma
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%
diff glioma/CBV accident
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.
diff astrocytoma/oligodendroglioma
Astrocytomas more T1w isointense or hyperintense than oligodendrogliomas
Oligodendrogliomas in contact with and distort ventricles and less peritumoral edema
maj local oligoden pirif lobe
MRI signal alterations relate to histologic tumor margins
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
T2w FLAIR mismatch signal in glioma
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
features high grade glioma
peripheral contrast enhancement
cystic region
hemmorrhage
drop metastasis
features of gliomatosis cerebri
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
FA value in cat compared to dog for meningioma
FA value of feline meningiomas have been reported as significantly higher than canine meningiomas
% neoplasic cells in LCS with choroid plexus carcinoma
50%
mechanism of radiation therapy
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)
dose of definitive radiotehrapy
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)
volumes radiotherapy
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)
Potential adverse effects associated with radiation therapy
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
MST with radiotherapy for
1. meningioma
2. glioma
3. choroid plexus tumor
4. trigeminal NST
5. multilobular tumor of bone
- 19-25 months
- 1-2 year, improve with chemo, multiple courses SRT
- 500 days (carcinoma less than 130)
- 441 to 952 days (clinical signs related to intracranial disease improved, but peripheral neuropathies did not improve)
- SRT 329 days, surg + RT 358 to 677 days
Which neoplasia can have CSF drop metastasis
Choroid plexus carcinoma
Oligodendroglioma
Age of maturity for background EEG rythms in dogs?
it takes from 5 to 12 months for background EEG rhythms to reach maturity in the dog and cat.
classic protocole for radiation therapy
Protocols applying 15-20 fractions of 2-3 Gy to total doses of 45-54 Gy over 4-5 weeks
side effect hypofractionned radiotherapy
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.
fatal complication radiotherapy
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
survival for subventricular glioma with stereotaxy
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).
bomark for diff struct epil and idiopathic epil
serum neurofil light chain (higher struct)
serum CRP (higher struct)
MRI features of lymphoma in cat
always enhancement (oft homogenous)
often meningeal enhancement
infiltration of adjacent extraneural tissue
illed defined margin
maj focal lesion
frequetly affected 2 compartment
T types lymphoma in cat
lymphomatosus cerebri
intravascular
lymphomatous meningitis (leptomeningeal)
% brain involvement in spinal lymphoma
30%
most involved site for neurolymphomatosis in cat
optic chiasm
imaging charact of T/B cell lymphoma in cat
T: older, leptomeningeal
B: extra-axial
CD44 exp: malignant potential
maj local of ependymoma + immunohisto
lateral
3rd ventricle
vimentine, pseudorosette (palissading around vessel), high mitotic rate
diff ventricular tumor
ependymoma, astrocytoma, histocytic sarcoma, meningioma, choroid plexus papilloma/carcinoma, lymphoma
+ granuloma, abcess, hematoma, congenit malfo
most common feline glioma type
astrocytoma > ependymoma
median survival time RT vs RT + VPS in solit intravent tumor
160 vs 1100
time to progression
70 vs 900
immunostain meningioma
E cadherin (meningothelial origin)
maningioma arise from arachnoid layer
diff extra axial mass cat
lymphosarcoma
meningioma
osteosarcoma
granuloma
microbleed and RT
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.
