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olfactory groove meningioma

Terms in this set (53)

ddx for lesion midline above sella
skull based meningioma (olfactory groove meningioma, tubercular sale meningioma)
pituitary adenoma
craniopharyngioma
Foster Kennedy syndrome
see with olfactory groove meningiomas
1. anosmia
2. unilateral optic atrophy
3. contralateral papilledema
Main factory that differentiate an olfactory groove meningioma from a tuberculum sale meningioma
location in the chiasm
optic nerves and chiasm are below the olfactory groove miningioma
vs
superolateral to tumor of tubercular sellae
Most common operative approaches to olfactory meningioma
1. subfrontal
2. Pterional
3. Interhemispheric
Subfrontal
bicoronal for >3 cm lesion
Unicoronal flap for <3cm

Pros:
1. early devascularization along skull base with division of feeding vessels
2. allows for access to orbits to coagulate ethmoidal arteries that supple these tumors
3. orbital osteotomies minimize frontal lobe retraction
4. allow for harvesting of vascularized pericranium for skull base reconstruction

cons:
1. opens frontal sinus, increasing risk of post op CSF leak and infection
2. sacrifice anterosuperior sagital sinus
Pterional
Pros:
1. early exposure of optic apparatus and carotid artery prior to tumor manipulation
2. early access to basal cisterns for CSF drainage for brain relaxation
3. shorter distance to tumor
4. avoid entry into frontal sinus
5. spares venous structures
6. less frontal lobe retraction unless orbital osteotomies are performed with sub frontal approach

cons:
1. narrow working angle
2. may be blinded in upper portion of tumor, which may require extensive frontal lobes retraction
3. frontal to access ethmoid arteries
4. difficult to repair basal skull defects
interhemispheric
pros:
preserves superior sagitall sinus
frontal sinus not opened

cons:
higher risk of contention to frontal lobes
operative route long and narrow
risk of bridging veins
difficult to access vascular supply
Genearl operative technique
1. Craniotomy +/- orbital osteotmies
2. early interruption of blood supply: if using sub frontal isolate and cauterize the ant an post ethmoidal arteries in the orbit, reduces risk of hemorrhage intra op
3. gentle retraction on frontal lobes to expose tumor
4. tumor capsule must be dissected, cauterized and opened
debulk the tumor - use cusa (ultrasonic aspirator)
5. at posterior aspect of tumor find an intact arachnoid plane (reliable in more beniegn tumor)
this separates the tumor from the anterior cerebral arteries, chasm, and optic nerves

should have excellent visualization of the anterior cranial fossa to allow for tumor resection and repair of defect
prognosis
high predilection for late recurrance at cranial base and sinuses
30% at 5 years
41% at 10 year

Aggressive primary section is sky
drill hypersonic bone
remove dural as well as sinus extension

must reconstruct skull base to avoid post op CSF leak and meningitis
Sphenoid wing Meningioma
patient presenting with chronic headaches, partial seizures since age 9, long history of decreased senate on left side of face, left sided weakness since a store a year ago,
right side blurry vision, gait disturbances.

MRI - fronto temporal dural based lesion abutting the sylvan fissure, attached to lateral aspect of sphenoid wing
DDX
meningioma
primary tumors: hemangiopericytoma, primary bone tumor
met
infeciton: abscess, subdural empyema, meningitis
vascular: avm
inflam: sarcoidosis
trauma: subdural or epidural
sphenoid wing meningiomas can be
lateral, intermedial or medial
Pre op prep
keppra
steroids for 48 hrs
control BP
surgical approach
Elevate HOB above heart
supine, with iplislateral shoulder bump
head rotated 30
use navigation

Pterional or cranio-orbito-zygomatic crani

expose lateral sphenoid wing extradurally via bone drilling of sphenoid
expose as little brain as possible
try to debulk inside of tumor as much as possible before retracting on capsule
use cusa (cation ultrasonic surgical aspirator) or cautery loop

use microscope
use buddy halo or greenberg halo with retractor sets

can remove en block if possible with rim of dura surrounding tumor

spare vessels in passage - especially in sylvain issue
drill out hypersonic bone
post op
dex x 1-2 weeks
keppra
icu
large dural defect after repair =
options to close :
1. Pericranium (have to harvest and potentially expand incision)
2. synthetic dural substitute (lyoplant)
3. bovine pericardium
4. fascia lata ( have to harvest)

closure further optimized by fibrin glue around the suture line to prevent sf seepage (druaseal)
grades of resection of meningioma
Simpson grading scale ( for meningiomas)

grade 1 - resection complete with dural attachment
grade 2 - coagulation of dural attachment (not removed)
grade 3 - resection of tumor only with dural attachment left behind)
grade 4 - subtotal resection
grade 5 - decompression
clinical implications of simpson grading
grade 2 = 20% recurrence at 5 years
seizures control
can be achieved in 88% of patients undergoing meningioma complete resection
Hemangiopericytoma
originates form pericytes in walls of blood vessles
but when in the the CNS it is meningeal tumor that has aggressive behavior
DDX - large hyper intense parasellar/clinoidal tumor
with midline shift, edema, hydrocephalus
hypo intense areas within a diffusely enhancing tumor = hypervascularity
1. meningioma
2. hemangiopericytoma
less likely: mets, glioma, lymphoma, brain abscess
management
admit to ICU
get labs
dex
keppra
angio for possible embolize
semi urgent surgery
approach
frontotemporal crani
classifying hemangiopericytomas vs meningioma
both are tumors or the meninges

hemagnioas are under subgroup of "mesenchymal (nonmeningothelial tumors)
along with tumors such as solitary fibrous tumors
malignant fibrous histiocytoma
chondrosarcoma

mangoes are in tumors of mengiothelial cells
adjuvant tx for hemagniopericytomas
considered a sarcoma = treat like that
chemo and rads are controversial

rads works well (according to imaging) so do for primary and recurrent
- can be fractionated or SRS

chemo - salvage only
doxorubicin, ifosfamide etoposide, methotrexate, cyclophosphamide, cisplatin, mitomycin, vincristine
prognosis for hemagniopericytomas
93% 5 years survival
89% 5 year disease free survival

80% recurrence , 30% with mets
common met sites for hemangioperictyomas
spine, long bones, liver, lung, abdominal cavity
clinoidal meningioma
one side vision loss
retro orbital pressure
funny smell that lasts 45 seconds
neuro exam with decreased visual acuity
inferior arcuate visual defect on right side
operative approach
frontoteporal craint for skull base approach
enables early decompression of optic nerve
and good exposure
ddx - lesion fronto temporal, enhances, at clinoidal region, compressing lateral and superior aspect of optic nerve
ddx: mengioma or hemagiopericytoma

also glioma, lymphoma, mets, abscess
classification of clinical meningiomas
Grade 1: tumor orgin proximal to end of cistern, attachment to the lower part of the cloned, encases the carotid artery within its cistern and adheres to adventitia in absence of an arachnoid membrane
Grade 2
originates from superior or lateral aspect of ant. clinoid process
comes into contact with carotid artery with presence of arachnoid membrane btw them, deriving from carotid and sylvain cisterns
Grade 3
tumor originates from optic foramen in which the arachnoid membrane is presented btw vessels and tumor but may be absent btw tumor and optic nerve
prior to OR
get neuro ophtho
CT head - look for hyperostosis
critical structures near clinical meningioma
optic and anterior cerebral arteires
pituitray stalk
contents of cavernous sinus (esp tumors that extend into it)
f/u plan post op
based on path and ant of residual
use simpson grading for recurrence ...
f/u with imaging
Velum interpositum meningioma
MRI: well circumscribed round mass in the pineal region, iso to cortex with homogenous enhancement
does not orig from pineal gland - pushing it

no mass effect on tectal plate or aqueduct of sylvius = no hydro
internal cerebral veins are pushed down and therefore are under the tumor
no relation to falcotentorial junction
DDX of mass like this
1. meningioma: in pineal region usually from tantrum cerebella and falx. Few cases with dural attachment at velum interpostium

2. pineoblastoma: usually large (>3cm) with perish calcifications, usually have obstructive hydroceph

3. pineocytoms: endhacnes, well circumscribed
calcify , rarely extend into 3rd vent

4. germ cell tumor: engulf pineal gland, hyperinetense to gray mater

5. astrocytoma: arise from midbrain tectum or thalamus, rarely from pineal gland

6. epdenymoma: mild to moderate heterogenous enchancement

7. mets
velum interpositum
space btw dorsal and ventral layers of tela choroidea
roof of 3rd ventricle
body and crura of fornices and dorsal and ventral layers of tea choroidea
vein located behind posterior wall of 3rd ventricle
vein of Galen
additonal studies to order
any mass in pineal region - need to follow algorithm for work up there, imaging alone can't dx
Pineal area tumor work up =
AFP, B hcg, - for germ cell tumors
measure in serum AND CSF
tx is chemo and rads only for germ cell tumors, no surgery

do met work up - CT c/a/p

MRI spine
surgical approaches
1. stereotactic bx
- ideal for pts who are poor surg candidates or with tumor invading brain stem
- there is a high risk of hemorrhage in pineal area

2. open surgical
- based on relation of tumor to deep venous system and surrounding structures
- tumor size and spread
- surgeon preference
open surgical approach options
1. infratentorial supracerebellar
2. occpitial transtentorial
3. posterior transcallosal
infratentorial supracerebellar
Do for tumor that displaces internal cerebral veins DORSALLY
reach via midline, below the deep cerebral veins
avoids volition of normal tissue
occipital transtentorial
do for lesion ABOVE deep venous system
midline
OR above the tectorial edge

negatives:
difficult to dissect tumor from tela chor of 3rd ventricle with this approach
need to rectration on visual cortex
posterior transcallosal
do for lesions anterior to the confluence of deep cerebral veins
for lesions that displace internal cerebral veins ventrally
pineal region
pineal gland is attached to posterior wall of 3rd ventricle
projects posteriorly in quadrigeminal cisterns
selenium of corps callous lies above this region and thalamus is on either side
roof of 3rd = body and crura for fornices and dorsal and ventral layers of tela choroidea
internal cerebral veins and medial posterior chorodial arteries course through this space
potential surgical complications
oculomotor deficits - including Parinaud syndrome
injury to deep venous structures:
- venous sinus tear, venous infarciton, venous air emboli
infratentorial - supracerebellar approach, related to sitting position (emboli)
transcallosal approach - hemisenosory or motor deficit (from retraction), venous cortical infarct, disconnection syndrome (damage to corpus callous - leads to aphasia, apraxia...)
transtentorial - visual field deficit, venous cortical infarct
*** PIC on page 34
meningioma of 3rd ventricle...orgin:
no dural attachment
mengiothelial cells are normally found in arachnoid and choroidal tela
during embryo development, arachnoid tissue migrates with choroid plexus as ventricle system invaginate
thus mengiocytes are found in storm of choroid plexus
ventricular meningiomas arise form choroid plexus! or from the tela chloroidea
velum interpositum
is a potential space btw dorsal and ventral layers of the tela choroidea
meningioma can orig from arachnoid cap cells of the tela choro in the 3rd ventricle
if arise from dorsal aspect - pushes internal cerebral veins ventrally
reported locations of meningiomas that there are no dural attachments
1. rare in cerebral ventricles
2. more common in atrium of lateral ventricles , esp left for un known reasons
less in 3rd vent and very rare in 4th
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