IMAGING OF INTRAVENTRICULAR TUMORS

2. • 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 finding at cross
sectional imaging
• May present with headaches signs and symptoms of increased
intracranial pressure, or a focal neurologic deficit.
• In addition, neoplasms involving the fourth ventricle may result in
ataxia or paresis.

3. • Many of these lesions have similar patterns of signal
intensity and contrast enhancement at imaging.
The location of the lesion in the ventricular
system along with knowledge of the patient’s
age, gender, and underlying conditions will help
narrow the differential diagnosis

4. • Lesion totally confined within the ventricle with
• Dilated ipsilateral ventricle
• Absence of brain edema
• Take the configuration of the ventricle

5. • Ependymomas account for 3%–5% of
intracranial neoplasms.
• They are generally well circumscribed
glial tumors with ependymal
differentiation that arise from the
ependymal cells of the ventricular wall.
• These lesions can occur either
supratentorially (40% of cases) or within
the posterior fossa (60%)

6. •Ependymomas can occur in any age
group but are more common in
younger patients.
•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

7. • Ependymomas are the third most
common brain neoplasm in children,
behind medulloblastoma (primitive
neuroectodermal tumor) and astrocytic
tumors.
• Presenting symptoms depend on the
location: Those that occur in the fourth
ventricle typically manifest with
symptoms of increased intracranial
pressure due to obstruction, ataxia, or
paresis

8. •Intraventricular ependymomas
are associated with a small risk of
spread throughout the CSF.
Therefore, imaging of the entire
neuroaxis should be performed to
assess for CSF dissemination

9. • Best diagnostic clue
○ Soft "plastic" tumor squeezes out through 4th ventricle foramina into cisterns
○ Heterogeneous density, signal intensity
○ ± indistinct interface with floor of 4th ventricle
CT MRI
• NECT
○ 4th ventricle mass
○ Ca++ common (50%); ±
cysts, hemorrhage
○ Hydrocephalus common
• CECT
○ Variable heterogeneous
enhancement
T1WI
○ Heterogeneous, usually iso- to hypointense
○ Cystic foci slightly hyperintense to CSF
○ Hyperintense foci (Ca++, blood products) common
• T2WI
○ Heterogeneous, usually iso- to hyperintense
○ Hyperintense cystic foci
• FLAIR
○ Can show sharp interface between tumor, CSF
• DWI
○ No restriction (relatively low cellularity)
• T1WI C+
○ Enhancement
– Varies from none to mild/moderate

12. • Medulloblastomas are the most common
malignant brain tumor of childhood.
• They most commonly present as midline
masses in the roof of the 4th ventricle with
associated mass effect and hydrocephalus.
• Account for 12-25 % of all pediatric CNS
tumors, and 30-40% of pediatric posterior
fossa tumors.
• They are also seen in adults, but only
account for 0.4-1.0% of adult brain tumors

13. • Moderate male predilection with a M:F ratio of
2:1
• Usually present in childhood with 77% of cases
before the age of 19. The median age of diagnosis
is 9 years.
• Growth of these very cellular tumours is often
rapid and accounts for their relatively rapid
clinical manifestation.
• Typically, presentation occurs over a few weeks
with features that are dominated by symptoms of
raised intracranial pressure as a result of
obstructive hydrocephalus.
• In approximately 40% of patients there is
evidence of CSF seeding at the time of diagnosis

14. • Best diagnostic clue
○ Most common: Round, dense 4th ventricle mass
CT MRI
• NECT
○ Solid mass in 4th ventricle
– 90% hyperdense
– Ca++ (up to 20%), hemorrhage
rare
– Small intratumoral cysts/necrosis
in 40-50%
○ Hydrocephalus common (95%)
• CECT
○ > 90% enhance
– Relatively homogeneous
– Occasionally patchy (may fill in
slowly)
T1WI
○ Hypointense to gray matter (GM)
• T2WI
○ Near GM intensity, or slightly hyperintense to GM
• FLAIR
○ Hyperintense to brain
○ Good differentiation of tumor from CSF in 4th
ventricle
• DWI
○ Restricted diffusion, low ADC
• T1WI C+
> 90% enhance
○ Often heterogeneous

18. Ependymoma Medulloblastoma
• Extrudes through 4th ventricle foramina
/foramen magnum
• Heterogeneous (Ca++, hemorrhage more
common)
• Higher ADC values (less cellular)
• Hyperdense on NECT
• Homogeneous mass
• Arises from roof of 4th ventricle
• More distinct interface with floor
• Low ADC, high cellularity
Apparent Diffusion Coefficients for Differentiation of Cerebellar Tumors in Children
1.Z. Rumboldta, D.L.A. Camachoc, D. Lakea, C.T. Welshb and M. Castilloc

19. • Subependymomas account for 0.2%–0.7% of
intracranial neoplasms.
• Most of these lesions occur in the fourth
ventricle (50%–60%) and lateral ventricles
(30%–40%).
• Rarely, they may arise from other
intraventricular sites or within the central
canal of the spinal cord

20. • Male predominance (male-to-female ratio, 2.3:1)
• 82% occur in patients older than 15 years.
• Most patients (60%) are asymptomatic; in those who are
symptomatic, the symptoms are most commonly related
to hydrocephalus.
• The majority are less than 2 cm in size, but symptomatic
lesions tend to be 4 cm or greater in size
• The classic scenariois a middle-aged man with an
incidental finding of an intraventricular neoplasm at
imaging.

21. • Best diagnostic clue
○ T2-hyperintense, lobular, nonenhancing, intraventricular mass
CT MRI
• NECT
○ Iso- to hypodense
intraventricular mass
○ Cysts or Ca++ may be seen
in larger lesions
○ Rarely hemorrhage
• CECT
○ No or mild enhancement
typical
T1WI
○ Intraventricular mass, hypo- or isointense to white
matter
○ Typically homogeneous solid mass
• T2WI
○ Hyperintense intraventricular mass
○ Heterogeneity related to cystic changes; blood products
or Ca++ may be seen in larger lesions
○ No edema seen in adjacent brain parenchyma
• FLAIR
○ Hyperintense intraventricular mass
• T1WI C+
○ Variable enhancement, typically none to mild

24. • The term central neurocytoma is reserved for
neurocytomas that occur in the ventricular
system
• Central neurocytomas account for 0.25%–0.5%
of intracranial tumors
• Central neurocytomas occur in the lateral
ventricle with or without extension into the
third ventricle and arise from the septum
pellucidum or ventricular wall

25. • The mean patient age is 29 years, but a wide
age range is reported, from 8 days to 67
years; there is no gender predilection.
• Patients typically present with symptoms of
increased intracranial pressure.

26. • Best diagnostic clue
"Bubbly" mass in frontal horn or body of lateral ventricle
CT MRI
NECT
○ Usually mixed solid and
cystic (iso-/hyperdense)
○ Ca++ common (50-70%)
○ Hydrocephalus common
○ Rarely complicated by
hemorrhage
• CECT
○ Moderate heterogeneous
enhancement
T1WI
○ Heterogeneous, mostly isointense to gray matter
○ Cysts are hypointense
○ Prominent flow voids may be seen
○ Hemorrhage is rare
• T2WI
○ Heterogeneous, hyperintense bubbly appearance
○ Associated hydrocephalus is common
○ Ca++ often hypointense
○ Prominent flow voids may be seen
• FLAIR
○ Heterogeneous, predominantly hyperintense mass
• T1WI C+
Moderate to strong heterogeneous enhancement

29. •SGCT is the most common cerebral
neoplasm in patients with tuberous
sclerosis (TS).
•Developing in up to 16% of cases
•Previously been referred to as
subependymal giant cell astrocytoma

30. • SGCT is considered pathognomonic for
TS, but there have been rare reports of
SGCT in patients without manifestations
of TS

31. • There is a wide age range for presentation,
from birth to the 5th decade (mean age, 11
years).
• These lesions arise near the foramen of
Monro, and it has been proposed that SGCTs
arise from a subependymal nodule.
• They are slow-growing lesions, and due to
their location they commonly manifest with
symptoms of increased intracranial pressure
from obstructive hydrocephalus

32. • Best diagnostic clue
○ Enlarging, enhancing foramen of Monro mass in patient with TSC
CT MRI
NECT
○ Hypo- to isodense;
heterogeneous
○ Ca++ variable
○ Hydrocephalus
• CECT
○ Heterogeneous, strong
enhancement
○ Presence of interval growth
suggests SGCA
○ Initially tumor is typically > 1
cm
T1WI
○ Hypointense to isointense to gray matter (GM)
○ ± Ca++ (hyperintense to hypointense)
• T2WI
○ Heterogeneous
– Isointense to hyperintense
○ Ca++ foci hypointense
○ Hydrocephalus
FLAIR
○ Heterogeneously hyperintense
○ Periventricular interstitial edema from ventricular obstruction
• DWI
○ Apparent diffusion coefficient (ADC) values are less than
parenchymal hamartomas of TS
• T1WI C+
○ Robust enhancement
○ Enlarging, enhancing foramen of Monro mass > 1.2 cm suggests
SGCA

35. • Are an uncommon, benign neuroepithelial
intraventricular tumour which can occur
mainly in paediatric age group.
• The tumours account for approximately 1%
of all brain tumours, 2-6% of all paediatric
brain tumours and 0.5% of the adult brain
tumours.
• Approximately 85% of all choroid plexus
papillomas occur in children under the age of
5 years

36. • Significant hydrocephalus is very
common - it is seen in over 80% of
cases.
• Although the exact mechanism
remains uncertain, it is believed to be
due to a combination of CSF
overproduction and decreased
arachnoid granulation resorption.

37. • Best diagnostic clue
○ Child with strongly enhancing lobulated (cauliflower-like) intraventricular mass
CT MRI
NECT
○ Intraventricular lobular mass
○ 75% iso- or hyperattenuating
○ Ca++ in 25%
○ Hydrocephalus
– Overproduction of CSF →
obstruction
• CECT
○ Intense, homogeneous
enhancement
– Heterogeneous enhancement
suggests choroid plexus carcinoma
○ No or minimal parenchymal
invasion
• T1WI
○ Well-delineated iso- to hypointense lobular mass
• T2WI
○ Iso- to hyperintense mass
○ ± internal linear and branching vascular flow voids
– Extensive invasion suggests CPCa
○ Hydrocephalus common
• FLAIR
○ Bright periventricular signal
– Periventricular interstitial edema due to ventricular
obstruction common
– Asymmetric ipsilateral T2 hyperintensity may suggest
invasion and CPCa
• T1WI C+
○ Robust homogeneous enhancement
○ Occasional cysts and small foci of necrosis
○ Look for CSF dissemination

40. • Choroid plexus carcinoma (CPC) is a
malignant neoplasm arising from the
choroid plexus.
• Choroid plexus carcinomas occurs
predominantly in children, typically in
the first 5 years of life, representing only
1-4%

41. • As is the case with choroid plexus
papillomas, presentation usually is as a
result of hydrocephalus.
• Symptoms include increasing head
circumference and headaches.
• Papilloedema may be visible on
fundoscopy.
• In addition, choroid plexus carcinomas
have a tendency to invade adjacent brain
and thus may present with focal
neurological dysfunction

42. • Best diagnostic clue
○ Child (< 5 years) with enhancing intraventricular mass and ependymal
invasion
○ Differentiation from choroid plexus papilloma (CPP) is histologic, not
radiologic
CT MRI
NECT
○ Iso- to hyperattenuating
mass with irregular
contours
○ Necrosis, cysts, and
hemorrhage common
○ Hydrocephalus
common
○ Calcification (Ca++) in
20-25%
• CECT
○ Heterogeneous, strong
enhancement
○ Peritumoral edema
○ ± CSF tumor seeding
T1WI
○ Iso- to hypointense intraventricular mass
○ Lobulated or irregularly marginated, papillary appearance
○ Heterogeneous (necrosis, cysts, hemorrhage)
• T2WI
○ Mixed signal mass, hypo-/iso-/hyperintense
○ Heterogeneous related to necrosis, cysts, hemorrhage, Ca++
○ ± prominent flow voids
○ Many invade brain and cause edema
• FLAIR
○ Heterogeneous intraventricular mass
○ Periventricular white matter edema suggests invasion
○ Transependymal CSF flow from hydrocephalus
• DWI
○ Low ADC values in solid portions of tumor
• T1WI C+
○ Heterogeneous enhancement, ± CSF seeding
Best diagnostic clue
○ Child (< 5 years) with enhancing intraventricular mass and ependymal invasion
○ Differentiation from choroid plexus papilloma (CPP) is histologic, not radiologic

45. Rare cases of CPC in adults have been reported;
however, whenever this potential diagnosis is
raised in an adult patient, it is imperative that
metastatic carcinoma to the choroid plexus be
ruled out, as these two entities may appear
similar at histologic analysis and metastasis is
far more common.
Intraventricular Neoplasms: Radiologic Pathologic Correlation, 2013 • radiographics

46. • Intraventricular meningiomas account for
0.5%– 3.7% of intracranial meningiomas
• The most common location for
intraventricular meningiomas is in the
atrium of the lateral ventricles.
• Less commonly, they may arise in the
third ventricle and rarely in the fourth
ventricle

47. • Like meningiomas elsewhere, they are most
common in females (female-to-male ratio, 2:1)
with a peak age range of 30–60 years.
• Meningiomas can also rarely affect the pediatric
age group, accounting for less than 3% of
intracranial neoplasms in this population.
• However, the intraventricular form accounts for
17% of pediatric meningiomas.
• No gender predilection is seen in the pediatric
age group,

48. • These neoplasms usually reach a large size
before patients become symptomatic;
• Patients typically present with signs of
increased intracranial pressure but may also
present with contralateral sensory or motor
deficits

49. CT MRI
NECT
CT reveals a well-defined, iso- to
hyperattenuating globular mass, ±
calcification
CECT
○ Heterogeneous, strong enhancement
• MR imaging demonstrates a mass that
is iso- to hypointense on T1-weighted
images and iso- to hyperintense on T2-
weighted images, and avid
enhancement is seen on contrast-
enhanced images.
• Local or diffuse ventricular dilatation
may be present, depending on the
degree of obstruction of CSF flow.
• Periventricular edema may be seen.
• Reduced diffusion may be seen in
some meningiomas, possibly reflecting
high cellular density in approximately
50% of cases

52. • Chordoid glioma is a WHO grade II, slow-growing glial neoplasm
involves the region of the anterior third ventricle and the
hypothalamus.
• These are rare lesions and therefore demographic information is
limited
• Female predominance (female-to-male ratio, 2:1 to 3:1) and a mean
age of 46 years are reported

53. • Given the location, patients typically present with hypothalamic
dysfunction, homonymous hemianopsia, or increased intracranial
pressure

54. • Best diagnostic clue
○ Well-delineated, homogeneously enhancing anterior 3rd ventricular
mass
MR Findings
• T1WI
○ 3rd ventricular mass isointense to brain
○ Hydrocephalus in 10-15% of cases
• T2WI
○ Iso-/hyperintense 3rd ventricular mass
• T1WI C+
○ Strong uniform enhancement

56. • RGNT is a recently described WHO grade I, rare primary brain tumor.
• It was included as a distinct glioneuronal neoplasm in the 2007 WHO
classification of tumors of the central nervous system.
• These neoplasms demonstrate glial and neuronal differentiation, and
it has been suggested that they arise from progenitor pluripotential
cells of the subependymal plate

57. • RGNTs typically occur in young adults (mean age, 31.5 years),
demonstrate indolent behavior,
• Do not tend to recur after surgical resection

58. • Patients usually present with signs of increased intracranial pressure
or ataxia
• There is a female predominance (female-to-male ratio, 1.75:1).
• RGNTs were originally described as solely occurring in the fourth
ventricle, but a recent case report describes an RGNT attached to the
septum pellucidum

59. • Best diagnostic clue
○ Midline cerebellar mass with solid-cystic appearance without
edema in young/middle-aged adult
CT MRI
CT Findings
• NECT
○ Midline posterior fossa cystic/solid
mass
○ Variable Ca++, hemorrhage
MR Findings
• T1WI
○ Iso-/hypointense mass
• T2WI
○ Hyperintense, heterogeneous
• T2* GRE
○ Hemorrhage common
• T1WI C+
○ Variable enhancement (none to heterogeneous)

61. • Intraventricular metastases account for
0.9%– 4.6% of cerebral metastases.
• In adults, renal, colon, and lung carcinoma
are the most common
causes;
• In children, neuroblastoma, Wilms tumor,
and retinoblastoma are most common.
• Renal cell carcinoma is remarkable in its
ability to produce solitary metastases up to
50 years after identification of the primary
lesion

62. • Intraventricular metastases are most
common in the lateral ventricles but
may also occur in the third ventricle and
very rarely in the fourth ventricle

63. • Best diagnostic clue:
○ "Unusual" mass in patient with known
systemic primary neoplasm
• Avid enhancement is usually seen on
contrast-enhanced images, and vasogenic
edema may be seen in the adjacent brain
parenchyma.

64. Known case of RCC
Choroid plexus metastasis

65. Known case of lung CA
Intraventricular metastasis

66. Known case of lung CA
Intraventricular metastasis

68. • MRI shows a large, heterogeneously enhancing mass with lobulated margins, centered within the
atrium of the right lateral ventricle.
▶ There is focal T1 hyperintensity within the tumor (black arrow), likely representing intratumoral
hemorrhage. There is a fluid–fluid level within the lateral ventricle due to dependent hemorrhage
(white arrows).
▶ There is T2 hyperintensity and enhancement possibly within the cerebral parenchyma along the
tumor margins consistent with parenchymal invasion.

69. • Differential Diagnosis
▶ Choroid plexus papilloma/ Choroid Plexus Carcinoma (CPC)
▶ Atypical teratoid-rhabdoid tumor
▶ Ependymoma
▶ Subependymal giant cell astrocytoma
▶ Central neurocytoma
▶ Metastasis

70. Diagnosis
•Choroid Plexus Carcinoma (CPC)
• Imaging cannot differentiate between CPC and papilloma, but
extraventricular invasion and CSF spread favor CPC.