36.Intracranial neoplasia

Question 1

most common primary brain tumor

Answer 1

menigioma–histopathologically benigndiscrete, mesenchymal tumorsmost often arise from arachnoid lay or meninges and extends inwarddolichocephalic breeds

Question 2

difference btwn cat and dog meningioma

Answer 2

cat–well encapsulated (male>female cats)dog–infiltrated (difficult to remove surgically)

Question 3

gliomas

Answer 3

type of primary brain tumorarises from supporting cells (astrocytes and oligodendrocytes)lots of variantsbrachycephalic breeds (Boxers, Bostons)

Question 4

non neoplastic disorder in young dogs

Answer 4

meningoangiomatosisnonneoplastic proliferative disorder of the leptomeninges

Question 5

location of most primary brain tumors

Answer 5

cerebrum > brainstem, cerebellum

Question 6

percentage of dogs with primary brain tumors have a concurrent unrelated neoplasia in chest and/or abdomen

Answer 6

23%

Question 7

most common clinical sign of brain tumor in dog vs cat

Answer 7

dog—seizure 50% (cats only 23%)cat–behavior change

Question 8

MRI findings of meningioma

Answer 8

1. extraaxial compression2. broad based3.+/- cystic component4. +/- dural tail5. +/- calcification (seen on non contrast images)6. uniform contrast enhancement7. distint tumor margins

Question 9

MRI findings of gliomas

Answer 9

1. intra-axial compression (w/in parenchyma)2. non-uniform contrast enhancement3. poor tumor margins4. highly infiltrative

Question 10

intraventricular tumors

Answer 10

–choroid plexus tumors–ependymomasuniformly contrast enhance

Question 11

accuracy of predicting tumor type based on MRI signs

Answer 11

only 65%

Question 12

palliation of tumor with GCC

Answer 12

oral prednisone 0.25-0.5 mg/kg q12hrdecreases intracranial pressure by decreasing vasogenic edema and decreasing CSF production

Question 13

what approach is most often utilized for removal of brain tumors

Answer 13

rostrotentorial craniotomy + durectomyskull defect is replaced with previous bone flap, titanium mesh and PMMA plate with titanium screws, PMMA, or remain open

Question 14

feline prognosis with meningioma

Answer 14

post operative survival times (with surgery)21.7-27 monthstumor recurrence rate 20-25%

Question 15

canine prognosis with meningioma

Answer 15

post operative survival times (with surgery)4.6-6.6 months

Question 16

other therapeutic options for intracranial neoplasia

Answer 16

1. definitive radiation2. sterotactic radiosurgery3. Hydroxy urea (induce tumor apoptosis)4. chemotherapy (hard to cross BBB)

Question 17

types of secondary brain tumors

Answer 17

mammary, pulmonary and prostatic carcinomasHSAmelanomaslymphomas

Question 18

most common secondary canine brain tumors

Answer 18

1. HSA2. pituitary tumors3. lymphomas

Question 19

most common secondary feline brain tumors

Answer 19

1. multicentric lymphomas2. pituitary tumors

Question 20

surgical option for pituitary tumors

Answer 20

hypophysectomyvia transsphenoidal or ventral paramedic approachesuseful for micro adenomas > macro adenomas

Question 21

dolichocephalic dogs predisposed to what secondary brain tumor

Answer 21

nasal or frontal sinus carcinomasandtumors of calvarium (OSA, chrondrosarc, multi lobular osteochondrosarcomas)

Question 22

small breeds (esp brachycephalic) are predisposed to what secondary brain tumor

Answer 22

pituitary macroadenomas