Primary The patients develop it from the start Is the most common type of glioblastoma 2 Secondary Progress from lower grades Note Once the histologic features of glioblastoma appear the prognosis is very poor with treatment resection radiotherapy and chemotherapy t ID: 776543
Download Presentation The PPT/PDF document " Glioblatomas are either:" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Glioblatomas
are either:
Primary
- The patients develop it from the start
Is the most common type of
glioblastoma
2. Secondary
Progress from lower grades
Note :
Once the
histologic
features of
glioblastoma
appear, the prognosis is very poor; with treatment( resection , radiotherapy , and chemotherapy), the median survival is only 15 months
Slide2Note:
Infatile
pilocytic
astrocytoma
is called
pilomyxoid
astrocytoma
and it is grade II typically located in the
hypothalamus
Morphology of
pilocytic
astrocytoma
Gross
:
Well circumscribed
Is often cystic, with a mural nodule in the wall of the cyst
Slide3Tumors that appear on MRI as cyst containing a nodule are:
Pilocytic
astrocytoma
Ganglioglioma
Pleomorphic
Xantho
astrocytoma
Slide4Microscopically,
pilocytic
astrocytoma
- The
tumor
shows
Hypercellular
areas composed of bipolar
astrocytes
with
with
long, thin "
hairlike
" processes that are GFAP positive
Hypocellular
areas formed of
microcysts
.
c. Rosenthal
fibers
d.
Eosinophilic
granular bodies,
e. Necrosis and mitoses are absent
.
Genetically
Pilocytic
astrocytomas
don’t show mutations in IDH1 and IDH2
Slide5Pilocytic astrocytoma
Slide6Pilocytic astrocytoma
Slide7B
.
Oligodendroglioma
- These
tumors
constitute about 5% to 15% of
gliomas
- Are most common in the fourth and fifth decades.
- Patients may have had several years of neurologic complaints, often including seizures.
- The lesions are found mostly in the cerebral hemispheres,
mainly in the frontal or temporal lobes
- Patients have better prognosis than
astrocytomas
of similar grade
Slide8Morphology
Gross
Are infiltrative
tumors
may show cysts,
hemorrhage
, and calcification.
Note: Is the most common CNS
tumor
showing calcification
On microscopic examination
,
1. Grade II
oligodendroglioma
:
Is composed of sheets of regular cells with spherical nuclei containing fine chromatin
The nuclei are surrounded by a clear halo of cytoplasm
Slide9Grade II oligodendroglioma
Slide10-
The
tumor
typically contains a delicate network of
anastomosing
capillaries.
- Calcification, present in as many as 90% of these
tumors
,
2. Grade III
anaplastic
oligodendroglioma
Characterized by:
Significant mitotic activity(minimum criterion)
And/or
microvascular
proliferation
And/ or
necrosis(geographic or
pseudopalisading
)
Slide11- Treatment with surgery,
chemtherapy
, and radiotherapy yield an average survival of 10-20 years for grade II and 5-10 years for grade III.
- The most common genetic findings in
oligodendrogliomas
is 1p19q
codeletion
-
Tumors
with just those specific changes have a consistent and long-lasting response to chemotherapy
Slide12C.
Ependymoma
-
Ependymomas
most often arise next to the
ependyma
-lined ventricular system, including the central canal of the spinal cord.
In
the first two decades of
life
a.
,
they typically
arise from floor of the fourth
ventricle
b. and
constitute 5% to 10% of the primary brain
tumors
in this age group.
In
adults
,
the spinal cord is their most common
location
; and
is considered as the most common type of
glioma
in the spinal cord in adults
Slide13tumors
in this site (if multiple) are particularly frequent in the setting of
neurofibromatosis type 2
Notes
- May arise in the
supratentorial
region
- The clinical outcome for completely
resected
supratentorial
and spinal
ependymomas
is better than for those in the posterior
fossa
Microscopically
:
1. Grade II
ependymomas
Are well circumscribed
gliomas
- Composed of cells with regular, round to oval nuclei
Between the nuclei there is a variably dense
fibrillary
background
Tumor
cells may form:
Round or elongated structures (
True
rosettes,
canals)
that resemble the embryologic
ependymal
canal with long, delicate processes extending into a lumen
Slide15True Rosettes of ependymoma
Slide16Are specific to
ependymoma
but are
infrequent
2
.
Perivascular
pseudo-rosettes
More frequently present
Not specific to
ependymomas
-
Tumor
cells are arranged around vessels with an intervening zone containing the
ependymal
processes
.
Slide17Ependymoma
Slide18Perivascular pseudo rosettes
Slide192.
Anaplastic
ependymomas
(grade III) show
:
Microvascular
proliferation
Pseudopalisading
necrosis
Note:- Presence of geographic necrosis can be seen in grade II
ependymomas
and
doesnt
upgrade
3.
Myxopapilllary
ependymoma
( grade I )
Arises in the
filum
terminale
and has good prognosis but tends to recur if not completely excised
Slide20II.
Neuronal
Tumors
1. Central
neurocytoma
(grade II)
- Is a low-grade neuronal neoplasm
Found
within and adjacent to the ventricular system (most commonly
at the level of foramen of Munro)
2
.
Gangliogliomas
- Are
tumors
with a mixture of
glial
elements (looking like a low-grade
astrocytoma
) and mature-appearing neurons.
Most
of these
tumors
are
slowly
growing
,
- These lesions often present with seizures
Slide21Embryonal
primitive
neoplasms
- The most common is the
medulloblastoma
,
accounting for 20% of
pediatric
brain
tumors
.
Medulloblastoma
(WHO grade IV)
occurs
predominantly in children
and
exclusively in the cerebellum.
-
The
tumor
is highly malignant,
The
prognosis for untreated patients is
dismal
- It is radiosensitive
- With total excision and radiation, the 5-year survival rate may be as high as 75%.
Slide22.
-
Tumors
of similar histology can be found elsewhere in the nervous system (called CNS primitive
neuroectodermal
tumor
, or CNS PNET
)
Morphology
- In children,
medulloblastomas
are located in the midline of the cerebellum (
vermis
) but may extend to the surface of the
cerebellar
folia and involving the
leptomeninges
- Lateral
tumors
(in
cerebellar
hemispheres) occur more often in adults.
Slide23Microscopically
a. Are extremely cellular, with sheets of
anaplastic
("small blue") cells
b. Individual
tumor
cells are small, with little cytoplasm and
hyperchromatic
nuclei;
Mitoses
are abundant.
May show Homer-
wright
rosettes
as evidence of neuronal differentiation
Slide24Medulloblastoma
Slide25medulloblastoma
Slide26IV. Primary Central Nervous System Lymphoma
Accounts for 1% of intracranial
tumors
.
A-
It is the most common CNS neoplasm in
immunosuppressed
individuals (including transplant recipients and persons with AIDS); under these circumstances the CNS lymphomas are nearly all driven by Epstein-Barr
virus and show
necrosis
B. In
non-
immunosuppressed
populations, the age spectrum is relatively wide, with the incidence increasing after 60 years of age
;
- Most of these
tumors
are diffuse large B-cell
lymphomas
- Regardless of the clinical context, primary brain lymphoma is an aggressive disease with relatively poor response to chemotherapy as compared with peripheral lymphomas
- Individuals with primary brain lymphoma often have multiple sites of
tumor
within the brain parenchyma;
-. Lymphoma arising outside the CNS rarely involves the brain parenchyma; when it does occur, there is usually
tumor
within the CSF and around
intradural
nerve roots
-
Slide28V
. Germ cell tumors
- Primary brain germ-cell tumors occur
commonly
in:
A. Pineal region
B.
suprasellar
region
- 90% occur during the first two decades of life
- CNS involvement by a
gonadal
germ-cell tumor is not uncommon
Slide29VI.
Meningiomas
:
- They occur in adults
- A
re
predominantly
benign tumors that arise from
arachnoid
cap cells and attached to the
dura
.
- May be found along any of the external surfaces of the brain as well as within the ventricular system, where they arise from the
arachnoid
cells of the choroid plexus.
- Clinically they either present with vague non-localizing symptoms, or with focal findings referable to compression of adjacent brain.
Slide30- Although most
meningiomas
are easily separable from underlying brain, some may infiltrate the brain, a feature that is associated with an increased risk of recurrence
- The overall prognosis is determined by the location, surgical accessibility, and
histologic
grade.
- When a person has multiple
meningiomas,with
bilateral vestibular
schwannomas
or spinal
ependymoma
, the diagnosis of NF2 syndrome should be considered
- About half of
meningiomas
not associated with NF2 have acquired loss-of-function mutations in the
NF2
tumor suppressor gene on the long arm of chromosome 22 .
- These mutations are found in all grades of
meningioma
,.
-
NF2
mutations are more common in tumors of certain patterns (fibroblastic, transitional,
psammomatous
).
Slide32Gross-:
WHO grade I grow as well-defined
dura
-based masses that may compress the brain but do not invade it and
extension into the overlying bone may be present and does not upgrade the tumor to grade II.
Microscopic :
Oval cells with indistinct borders and
Intranuclear
pseudoinclusions
arranged in
syncytia
with
whorling
Slide33Meningioma
Slide34Meningeoma
Slide35Grade I
No more than 3 MF/10HPF
2. Grade II
meningeoma
are recognized by either:
A. Mitotic figures of more than 3 but less than 20 per 10 HPF(high power fields)
B. Or presence of 3 of the following 5 atypical features
1. Small cells,
2. Prominent nucleoli ,
3. Sheeting
4.
Hypercellularity
,
5. Spontaneous necrosis not induced by
embolization
Slide36C. Or Brain invasion
D. Clear or
chordoid
variants
- These tumors are more aggressive with a higher rate of recurrence and may require radiation therapy in addition to surgery
3.
Anaplastic
(malignant)
meningiomas
(WHO grade III)
- Are highly aggressive tumors characterized by either:
a. They resemble a high-grade sarcoma or carcinoma or melanoma
b. Or Mitotic figures of 20 or more per 10HPF(high power fields)
c. Papillary or
rhabdoid
variants
Slide37VII. Metastatic Tumors
- The most common primary sites are lung, breast, skin (melanoma), kidney, and gastrointestinal tract-
- Metastases form sharply demarcated masses, often at the gray-white junction, and elicit marked edema
- The boundary between tumor and brain parenchyma is sharp at the microscopic level as well
Slide38CNS
manifestaions
of Familial Tumor Syndromes
I. Tuberous Sclerosis :
- Is an
autosomal
dominant syndrome characterized by
a. The development of CNS
hamartomas
consist of: Cortical tubers which are associated with seizures and can be difficult to control with antiepileptic drugs.
b. Benign brain
neoplasms
such as
subependymal
giant cell
astrocytoma
and because of their proximity to the
Slide39foramen of
Monro
, they present acutely with obstructive hydrocephalus, which requires surgical intervention
2
. v
on
Hippel-Lindau
Disease:
- An
autosomal
dominant
- The CNS tumor is
hemangioblastoma
(grade I)
Hemangioblastomas
insporadic
cases occur in the
cerebellar
hemispheres and spinal cord
In
v
on
Hippel-Lindau
Disease:
, tend to occur as multiple lesions
in the
spinal cord
Paraneoplastic
syndromes affecting the brain
1.
Subacute
cerebellar
degeneration
- Resulting in ataxia, with destruction of Purkinje cells,
2. Limbic encephalitis
:
- Causing a
subacute
dementia,
-
Charcterized
by
perivascular
inflammatory cells, some neuronal loss, and
gliosis
, in the medial temporal lobe
Slide413.
Syndrome of rapid-onset psychosis, epilepsy, and coma
- Associated with ovarian
teratoma
and antibodies against the
N
-methyl-d-
aspartate
(NMDA) receptor