Tumors of the Nervous System Flashcards
What is overall estimated incidences of canine and feline nervous system tumors?
Canine: 14,5/100 000 cases; 2-4.5% at necropsy
Feline: 3,5/100 000 at risk; 2% at necropsy
Classify the different subtypes of PBT in descending order based on their frequency
+/- 90% of PBT are represented by meningioma (45%), glioma (40%) and choroid plexus tumor (5%)
Less common: ependymoma, lymphoma, PNETs, GC, HS
What’s more frequent: Primary vs Secondary brain tumors?
Pretty much 50/50
What are the most common secondary brain tumors?
HSA (29-35%), pituitary tumors (11-25%), lymphoma (12-20%), metastatic carcinoma (11-20%) = total of 77-86% of all SBTs
Is there a sex predisposition in canine brain tumors?
No
Median age at diagnosis ?
Middle-aged to older dogs; majority > 5yo
Meningioma 10.5yo
Glioma 8 yo
CPT 5.5 yo
PBT in juvenile animals are of what origin?
Propensity to be neuroepithelial tumors of glial, neuronal, or embryonal origin
Is there a relationship between age and BW in PBT occurrence ?
large-breed dogs at increased risk for meningioma and CPTs
What breeds are overrepresented with canine meningioma?
Golden Retr, boxers, schnauzer, rat terrier
What breeds are overrepresented with canine CPTs?
One report said golden retrievers but other reports did not confirm
What breeds are overrepresented with canine gliomas?
Brachycephalic!
Boxer, Boston, bullmastiff, bulldogs
What tumor has been identified with a genetic defect association? What is that defect?
- Gliomas
- Locus on canine chromosome 26 –> single nucleotide variant in 3 genes (DENR, CAMKK2, P2RX7)
What is the ratio of PBT vs SBT in cats? What is the most common PBT?
70% of PBTs; more than 50% of those are meningiomas
Most common SBTs in cats?
- Lymphoma (50%)
- Pituitary tumors (30%)
Median age at diagnosis in cats?
11yo for meningiomas; 7-8 yo for neuroepithelial tumors and lymphoma
Sex predisposition in cat brain tumors?
No
% of seizures in dogs with forebrain tumor?
50%
Risk factors for tumor-associated structural epilepsy based on MRI?
presence of tumor involving frontal lobe, falcine or subtentorial brain herniation, marked contrast enhancement
Incidence of tumor-associated epilepsy in cats?
< dogs; 25%
Possibly more common with glioma (27%) and lymphoma (26%) than meningioma (15%)
What is the most common clinical sign in cats with brain tumors?
Behavioral changes (16-67%)
Based on the appearance, what is your likely diagnosis?
Butterfly glioblastoma
How frequent is it to detect multiple tumors in cats vs dogs?
Cats 20% vs dogs only occasionally
What is the unique presentation of metastasis in choroid plexus carcinoma ?
Drop metastases
What tumor may metastasize in the CNS in a unique way called ‘drop metastases’ ?
Choroid plexus carcinomas
What is the incidence of contemporanous and unrelated neoplasms in dogs with PBTs?
3-23%
Accuracy of MRI to predict PBT type?
70%
MRI features of meningiomas
Extra-axial, broad-based, distinct margins, marked and uniform contrast enhancement; some can display intratumoral fluid, cysts, mineralization, calvarial hyperostosis, dural tail sign
Accuracy of MRI to correctly identify meningioma in dogs vs cats?
between 60-100% in dogs; 96% in cats
Glioma’s features on MRI?
intra-axial, poorly marginated, may or may not show contrast enhancement (highly variable), ‘ring enhancing’ pattern often seen in gliomas but not specific
What tumors are most commonly found in intraventricular locations?
Choroid plexus tumors and ependymomas
MRI features of CPT and ependymomas?
Usually intra-ventricular; often uniformaly contrast enhancing
What MRI finding car discriminate between grade III choroid plexis carcinoma and grade I papilloma?
Identification of intraventricular or subarachnoid metastatic tumor implants
What brain tumors are known to be occult (normal MRI) on imaging studies of the brain?
Lymphamatosis and gliomatosis cerebri
What are the different subtypes of meningiomas?
angiomatous, meningothelial, transitional, fibroblastic, psammomatous, microcystic, papillary
What subtypes of meningiomas are more frequent?
Meningothelial, transitional and psammomatous (in both species)
Frequency of grade 1, 2 and 3 meningiomas? in both species
Majority of feline meningiomas = grade 1
Dogs: 40% are grade 2
Anaplastic, grade 3, meningiomas = 1% in dogs and cats
Frequency of CPT grades in the dog?
Grade 1: 40%
Atypical (grade II) not yet recognized in vet med
Grade 3: 60%
Nearly 50% occur in 4th ventricule
Is CSF helpful in the diagnosis of choroid plexus tumors?
Helpful to discriminate between CPC and CPPs –> CSF tot protein > 80 mg/dL exclusively associated with diagnosis of CPC
What tumors seem to exfoliate more in the CSF?
CPTs, lymphoma, HS and cats with caudal brainstem oligodendrogliomas are the most frequently reported
What is the prevalence of head and neck hyperesthesia in dogs with brain tumors?
12%
MST of PBTs with palliative care?
+/- 9 weeks, range 1-13wks but dogs with supratentorial tumors treated palliatively > outcome with 25 weeks compared to 4 weeks for infratentorial
MST for pituitary tumors treated palliatively?
MST 51 weeks in one study
Efficacy of chmotherapy for PBTs?
Retrospective study of 71 dogs –> CCNU 93d vs palliative 60d; not statistically significant
MST for cats with meningiomas treated surgically?
Often > 2 years, reported MST from 23-37 months
% of recurrence of feline meningiomas after surgery?
25%, time to recurrence very variable (3-69 months)
MST of canine meningiomas treated with sx?
7-16 months
MST of canine meningioma treated with sx + RTH ?
16-30 months
What are two types of SBTs that have a good prognosis following surgery?
Pituitary tumors and calvarial MLO
% of surgical complications ?
+/- 11%
MST for presumed meningiomas treated with RT?
MST 9-19 months
MST for intra-axial masses treated with RT?
MST 9-13 months
What biomarker holds prognostic value in meningiomas?
- VEGF; MST 25 mo with low VEGF vs 15 mo high VEGF (> 75%)
- Progesterone receptor expression: 2y SR = 42% if 24% or greater vs 91% if less than 24%
