intraventricularneoplasms 161007063447

INTRADãnVENTRICULAR
não thất III và
não thất bên hai
NEOPLASMS
bên, phù mô kẽ
quanh não thất bên
hai bên.

PRESENTED BY
Dr Fahad Shaf


• A variety of neoplasms may arise in the
ventricular system.
• According to the lesion size and location,
patients may be asymptomatic with the mass
found as an incidental fnding at cross-sectional
imaging or
• may present with headaches, signs and
symptoms of increased intracranial pressure, or
a focal neurologic defcit


Ventricular Anatomy
• differential diagnosis of intraventricular
neoplasms is broad. To understand the
different entities that can occur in an
intraventricular location, it is important to
understand the embryology, anatomy, and
histologic structure of the ventricular system.

ependymal-lined outpouchings from the cranial end of the neural tube, which are called the telencephalic
vesicles.
choroid plexus develops from an invagination of primitive pia-arachnoid and vessels into these vesicles, thus
creating the choroidal fssures.


• The septum pellucidum is also lined by glial cells and residual neuronal
precursor cells, from which the central neurocytoma may arise.
• The very vascular choroid plexus produces cerebrospinal fluid (CSF) and may
give rise to primary neoplasms of the choroid plexus (choroid plexus
papilloma, atypical choroid plexus papilloma, choroid plexus carcinoma);
owing to its vascular supply, it may contribute to deposition of metastases in
this location.
• Arachnoidal cap cells, which make up the arachnoid granulations, may
become trapped within the choroid plexus during embryologic development;
these cells can give rise to meningiomas.


IMAGING MODALITIES
• 1. Plain skull radiographs–May demonstrate calcification and evidence of raised
intracranial tension.
• 2. Plain and contrast enhanced CT–May help in characterization of the lesion
confrming the presence of calcifcation. MDCT may help in better localization
through its multiplanar capability with the help volumetric data acquisition.
• 3. Conventional ventriculography/CT ventriculography – It has become obsolete
with the advent of MRI.
• 4. MRI – It has transformed the way we look at intracranial lesions with its
exquisite resolution and multiplanar capability.
• 5. Angiography – Indicated in vascular malformations and for angioembolization

MEDULLOBLASTOMA
• MC malignant brain tumours in children.
• Commonly present as midline masses in the roof
of 4th ventricle.
• Account for 12-25% of pediatric cns neoplasms
ans 30-40% of posterior fossa tumours.In adults
account for 0.4-1% of cns neoplasms.


• M:F =2:1
• Mean age of diagnosis is 9 yrs
• Growth is rapid hence present with over few
weeks.
• 40% cases show CSF dissemination at the time
of diagnosis.


 medulloblastoma in a typical location within the midline of the posterior fossa. On imaging studies, medulloblastoma
commonly appears heterogeneous, due to areas of hemorrhage, cyst formation, and occasional areas of calcifcation,
as depicted here. Leptomeningeal seeding, which is also illustrated here, is often seen in imaging studies.


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NECT

Solid mass in the 4th ventricle
Ca2+ in upto 20%
Small tumor cysts and hemorrhage in 40 to
50%
• >90% enhance homogenously, occasionally
may be patchy.


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T1wi hypo to GM
T2WI Iso to hyper
Hyperintense on FLAIR.
Good differentiation of tumour from CSF in 4th
ventricle.
• DWI restricted diffusion.
• T1wI C+ >90% enhance often heterogenously.


NECT


T1WI,T2WI &T1WI C+


Ependymoma
•  3%–5% of intracranial neoplasms

• generally well-circumscribed glial tumors with
ependymal differentiation that arise from the
ependymal cells of the ventricular wall
• either supratentorially (40% of cases) or within
the posterior fossa (60%)
•  More than one-half of supratentorial
ependymomas are intraparenchymal, with the
remainder being intraventricular 


• Ependymomas can occur in any age group but are
more common in younger patients.
• Those that occur in the posterior fossa are more
common in children (mean age, 6 years), whereas
the mean age for supratentorial lesions is 18–24
years
• Ependymomas are the third most common brain
neoplasm in children, behind medulloblastoma
(primitive neuroectodermal tumor) and astrocytic
tumor


symptoms
• Those that occur in the fourth ventricle
typically manifest with symptoms of increased
intracranial pressure due to obstruction,
ataxia, or paresis, whereas supratentorial
lesions manifest as headache, focal neurologic
defcit, or seizure

Pathologic Findings
• Ependymomas are classifed as either World
Health Organization (WHO) grade II (low-grade,
well-differentiated) or grade III (anaplastic)
neoplasms
•  At gross inspection, these are soft “plastic”
neoplasms. In the region of the fourth
ventricle, they may extend through the
foramen of Luschka into the cerebellopontine
angle cistern or through the foramen magnum


 Ependymoma of the fourth ventricle in a 2-year-old girl. Photograph of a midline sagittal plane
section through the posterior fossa shows a mass that extends from the fourth ventricle through
the foramen of Luschka (arrow) into the cerebellopontine angle


[H-E] stain) shows a moderately cellular glial neoplasm with a perivascular
pseudorosette (arrow). No mitotic activity is present.


Imaging Features
• Ependymomas frequently demonstrate cystic
components and areas of small chunky
calcifcation.
• Occasionally, intratumoral hemorrhage may be
seen. At computed tomography (CT), the softtissue portion is commonly hypo- to
isoattenuating

Ependymoma in a 2-year-old girl with ataxia and headaches. Nonenhanced CT image shows a
solid and cystic lesion that arises from the fourth ventricle and extends through the foramen of
Luschka into the cerebellopontine angle. The solid portion is slightly hyperattenuating relative to
the adjacent cerebellum. Areas of calcifcation are also present. The mass results in
hydrocephalus, with dilatation of the third and lateral ventricles.


MR
• they are iso- to hypointense on T1-weighted images
and iso- to hyperintense on T2-weighted images.
• Heterogeneous enhancement is seen on contrast
material–enhanced images.
• Blooming may be seen on T2*-weighted images if
calcifcation or hemorrhage is present.
• Findings on diffusion-weighted images are variable.
Reduced diffusion may be seen in the soft-tissue
component of some ependymomas, a fnding that most
likely reflects higher cellularity in some neoplasms


Fourth ventricle ependymoma in a 6-year-old boy. (a) Sagittal T1-weighted image
shows a hypointense lesion flling and conforming to the fourth ventricle with
extension through the foramen magnum. (b) On a T2-weighted image, the neoplasm is
hyperintense. Resultant hydrocephalus is present


Intraventricular lesions may extend into adjacent brain, and
there may be vasogenic edema in the adjacent periventricular
white matter

PROGNOSIS
• The 5-year survival rate in children is reported to be 50%–75% .
• Children have a less favorable prognosis than older patients, in part due
to the higher prevalence of fourth ventricle lesions; in addition, there is a
greater predilection for the anaplastic form in the pediatric population .
• Surgery plays an important role in treatment, but surgical resection is
often difficult due to adherence and the infltrating nature of the tumor.
• If the resection is subtotal, the ependymoma tends to recur. With
recurrence the prognosis is very poor, with a mortality rate of
approximately 90%