meningiomas dr david cuenca
Post on 30-May-2018
220 Views
Preview:
TRANSCRIPT
-
8/14/2019 Meningiomas Dr David Cuenca
1/43
MENINGIOMAS
J. DAVID CUENCA RIVAS. MDNEUROSURGERY
-
8/14/2019 Meningiomas Dr David Cuenca
2/43
Definition
Meningothelial (arachnoidal) cell neoplasms,
typically attached to the inner surface of thedura mater.
-
8/14/2019 Meningiomas Dr David Cuenca
3/43
-
8/14/2019 Meningiomas Dr David Cuenca
4/43
G rading
Most meningiomas are benign andcorrespond to WHO grade I.Certain histological subtypes or meningiomaswith specific combinations of morphologicparameters are associated with less
favourable clinical outcomes and correspondto WHO grades II (atypical) and III (anaplasticor malignant).
-
8/14/2019 Meningiomas Dr David Cuenca
5/43
-
8/14/2019 Meningiomas Dr David Cuenca
6/43
I II III IV
-
8/14/2019 Meningiomas Dr David Cuenca
7/43
-
8/14/2019 Meningiomas Dr David Cuenca
8/43
-
8/14/2019 Meningiomas Dr David Cuenca
9/43
Incidence
Meningiomas account for about 24 30% of
primary intracranial tumours occurring in theUSA {305, 359}, with an annual incidence rateof up to 13 per 100 000 population in Italy{381}.
-
8/14/2019 Meningiomas Dr David Cuenca
10/43
Age and sex distribution
Meningiomas occur most commonly in middle-aged and elderly patients, with a peak during thesixth and seventh decades. Nonetheless, theyalso occur in children and the elderly. Childhoodexamples tend to include more aggressive forms
of meningioma. Among middle-aged patients,there is a marked female bias, the female:maleratio being approximately 1.7:1
-
8/14/2019 Meningiomas Dr David Cuenca
11/43
Etiology
Meningiomas are known to be induced by
low-, moderate-, and high-dose radiation, withan average time interval to tumourappearance of 35, 26 and 19 24 years,respectively.
-
8/14/2019 Meningiomas Dr David Cuenca
12/43
The role of sex hormones in the genesis of
meningiomas is less clear.
-
8/14/2019 Meningiomas Dr David Cuenca
13/43
Localization
The vast majority of meningiomas arise in
intracranial, intraspinal or orbital locations.Intraventricular and epidural examples areuncommon.Rare meningiomas have been reported inalmost all organs.
-
8/14/2019 Meningiomas Dr David Cuenca
14/43
Localization
Within the cranial cavity, most meningiomas
occur over the cerebral convexities, oftenparasagittal in association with the falx andvenous sinus.
-
8/14/2019 Meningiomas Dr David Cuenca
15/43
Localization
Other common sites include the olfactory
grooves, sphenoid ridges, para/suprasellarregions, optic nerve sheath, petrous ridges,tentorium and posterior fossa.Most spinal meningiomas occur in thethoracic region.
-
8/14/2019 Meningiomas Dr David Cuenca
16/43
Localization
Atypical and anaplastic meningiomas most
commonly affect the falx and the lateralconvexities.
-
8/14/2019 Meningiomas Dr David Cuenca
17/43
-
8/14/2019 Meningiomas Dr David Cuenca
18/43
SYMPTOMS AND SIGNS
Clinical features
-
8/14/2019 Meningiomas Dr David Cuenca
19/43
Symptoms and signs
Meningiomas are generally slowly growing
and produce neurological signs and symptomsby compression of adjacent structures;specific deficits depend upon the location of the tumour.
-
8/14/2019 Meningiomas Dr David Cuenca
20/43
Symptoms and signs
Headache and seizures often herald the
presence of a meningioma.
-
8/14/2019 Meningiomas Dr David Cuenca
21/43
Neur oimaging
On MRI,meningiomas
are typicallyisodense,contrast-enhancingdural masses.
-
8/14/2019 Meningiomas Dr David Cuenca
22/43
Neur oimaging
Some, like microcystic meningiomas, may
show little enhancement on CT
and MRI
-
8/14/2019 Meningiomas Dr David Cuenca
23/43
Neur oimaging
Calcification is best seen on C T scan.
A characteristic feature of meningiomas is theso-called dural tail surrounding the duralperimeter of the mass.
-
8/14/2019 Meningiomas Dr David Cuenca
24/43
Neur oimaging
P eritumoural cerebraledema is occasionallyprominent, particularlyaround atypical oranaplastic examples.
-
8/14/2019 Meningiomas Dr David Cuenca
25/43
Neur oimaging
It has also been described in association with
the secretory variant and in meningothelialtumours with so-called pericyte accumulationabout vessels.
-
8/14/2019 Meningiomas Dr David Cuenca
26/43
Macroscopy
Most meningiomas arerubbery or firm, well-demarcated, sometimeslobulated, roundedmasses that featurebroad dural attachment.
-
8/14/2019 Meningiomas Dr David Cuenca
27/43
Macroscopy
Invasion of underlyingdura or of dural sinuses isquite common.Occasional meningiomasinvade through dura toinvolve the skull, wherethey may inducecharacteristic
hyperostosis: such bonychanges are highlyindicative of skullinvasion.
-
8/14/2019 Meningiomas Dr David Cuenca
28/43
Macroscopy
Meningiomas mayattach to or encasecerebral arteries, butonly rarely do theyinfiltrate arterial walls.
-
8/14/2019 Meningiomas Dr David Cuenca
29/43
Macroscopy
They may also infiltratethe skin and extend toextracranialcompartments, such asthe orbit.
-
8/14/2019 Meningiomas Dr David Cuenca
30/43
Macroscopy
In certain sites,particularly along thesphenoid wing,meningiomas may growas a flat, carpet-likemass, a pattern termed
en plaquemeningioma.
-
8/14/2019 Meningiomas Dr David Cuenca
31/43
H istopathology
Of the subtypes in the WHO classification,
meningothelial, fibrous and transitionalmeningiomas are the most common.
-
8/14/2019 Meningiomas Dr David Cuenca
32/43
H istopathology Like normal arachnoidal cap cells, thetumour cells are largely uniform,
with oval nuclei with delicatechromatin that on occasion showcentral clearing, or the formulationof cytoplasmic-nuclear inclusions.
Meningothelial meningioma
In this classic and commonvariant, tumour cells formlobules, some partly
demarcated by thincollagenous septae.
Whorls and psammomabodies are not common inmeningothelialmeningioma
-
8/14/2019 Meningiomas Dr David Cuenca
33/43
H istopathology The tumour cells of fibrousmeningioma form wide fascicles,
with varying amounts of intercellularcollagen.F ibrous (fibroblastic)meningioma.
Consists of spindle cells
forming parallel, storiformand interlacing bundles ina collagen-rich matrix.
Nuclear featurescharacteristic of meningothelialmeningioma are oftenfound focally as well.
-
8/14/2019 Meningiomas Dr David Cuenca
34/43
H istopathologyVaguely lobular and fasciculararrangements often appear side by
side in association with conspicuoustight whorls and psammoma bodies.Transitional (mixed)meningioma.T hese common tumoursfeature the coexistence of meningothelial and fibrouspatterns as well as transitionsbetween these patters.
-
8/14/2019 Meningiomas Dr David Cuenca
35/43
-
8/14/2019 Meningiomas Dr David Cuenca
36/43
H istopathology
The differential diagnosis includes vascular malformationsand capillary haemangioblastoma, depending on theprominence of vessels and the occasionally nonMeningothelial appearance of the tumour cells.
Angiomatous meningiomas do not exhibit aggressive behaviour.Adjacent cerebral edema may be out of proportion to tumoursize.
Angiomatous meningiomaP redominance of bloodvessels over that of thetumour cells. The vascularchannels may be small- or
medium-sized, thinwalledor thick.
-
8/14/2019 Meningiomas Dr David Cuenca
37/43
H istopathology
P leomorphic cells may be numerous, but microcystic meningiomas are typicallybenign. Like the angiomatous variant, accompanyingcerebral edema may be seen.
Microcystic meningiomaCharacterized by cells with thin,elongate processes encompassingmicrocysts containing pale,eosinophilic mucinous fluid.
-
8/14/2019 Meningiomas Dr David Cuenca
38/43
H istopathology
Secretory meningiomaFocal epithelial differentiationin the form of intracellular luminacontaining PAS-positive, eosinophilicsecretion.
These structures, known aspseudopsammoma bodies.
Show immunoreactivity forcarcinoembryonic antigen (CEA) and avariety of other epithelial and secretorymarkers
Secretory meningiomas may beassociated with blood levels of CEAthat drop with resection and rise withrecurrence.
-
8/14/2019 Meningiomas Dr David Cuenca
39/43
H istopathology
Lymphoplasmacyte- rich meningioma is among the rarestof variants.
Lymphoplasmacytic-richmeningiomaThis meningioma variant featuresextensive chronic inflammatoryinfiltrates often over-shadowing theinconspicuous meningothelial
component.
Systemic haematologic abnormalities, including hyperglobulinemia and iron refractoryanemia have been documented in some cases.
-
8/14/2019 Meningiomas Dr David Cuenca
40/43
H istopathology
Correlation with intra-operative findings is occasionally needed to distinguishossified meningiomas from ones exhibiting bone invasion.
Metaplastic meningioma
Mesenchymal componentsincluding osseous, cartilaginous,lipomatous, myxoid or
xanthomatous tissue,singly or in combinations.
-
8/14/2019 Meningiomas Dr David Cuenca
41/43
H istopathology
C hordoid meningioma
WHO Grade II
Consisting predominantlyof tissue histologically similar tochordoma, featuring cords ortrabeculae of eosinophilic, oftenvacuolated cells in an abundantmucoid matrix background.
Chordoid meningiomas
are typically large, supratentorialtumours that exhibit a very highrate of recurrence followingsubtotal resection
Chronic inflammatory infiltrates, often patchy, maybe prominent.
Infrequently, patients have associatedhaematological conditions, such as Castleman sdisease
-
8/14/2019 Meningiomas Dr David Cuenca
42/43
H istopathology
Composed of polygonal cells with clear, glycogen-rich cytoplasm and prominentblocky perivascular and interstitial collagen.
C lear cell meningioma
WHO Grade II A rare meningioma variant, it showsprominent PAS-positive, diastasesensitivecytoplasmic clearing due to glycogenaccumulation.
Classic features of meningioma arefew; whorl formation is vague at bestand no psammoma bodies are seen.
P roclivity for the cerebellopontine
angle and cauda equina region.
It also tends to affect youngerpatients.
-
8/14/2019 Meningiomas Dr David Cuenca
43/43
H istopathology
Increased mitotic activity is defined as 4 or more mitoses per 10 high-power(40x) fields (defined as 0.16 mm2).
Atypical meningioma
WHO Grade II Increased mitotic activity or three ormore of the following histologicfeatures:Increased cellularitySmall cells with a high nuclear:Cytoplasmic ratioP rominent nucleoliUninterrupted patternless or sheet-like growth.Foci of spontaneous or
geographic necrosis.
Simply combine hypercellularity with 5 or more mitoses per 10 high power fields.
top related