Intraventricular tumours Sumeet Kumar

National Neuroscience Institute

Duke-NUS Medical School

Singapore

Intraventricular tumours

• Ependymoma

• Subependymoma

• Choroid plexus Papilloma/Ca

• Subependymal Giant cell Tumour/ Astrocytoma (SEGA)

• Meningioma

• Central Neurocytoma

• Others- GBM, Lymphoma, RGNT (Rosette forming Glioneuronal Tumour), Metastases

Cells of origin of intraventricular tumours

• Epithelial lining of ventricles- ependyma → ependymoma

• Adjacent to ependymal lining- subependymal plate of glial cells → subependymoma

• Choroid plexus → choroid plexus tumours- papilloma, atypical papilloma, carcinoma

• Vascularity of choroid plexus → metastases

• Arachnoidal cap cells which form arachnoid granulations can be trapped in the choroid plexus → meningioma

• Septum pellucidum lined by glial cells and neuronal precursor cells → central neurocytoma

Ependymoma

• Arise from epithelial lining of ventricles- ependyma

• Parenchymal ependymomas arise from embryologically trapped ependymal cells

Ependymal cells lining the ventricles

http://missinglink.ucsf.edu/lm/introductionneuropathology

Ependymoma

• 3-5% of intracranial neoplasms

• 60% posterior fossa

• 40% supratentorial

• Half parenchymal and half intraventricular

• More common in children (1-6 years)

In the posterior fossa

• Supratentorial lesions- mean age 18-24 years

• Children have a worse prognosis- higher prevalence of anaplastic form

Ependymoma

• Gross pathology- soft “plastic” tumours, “toothpaste”tumours

• 4th ventricular tumours extend through foramen of Luschka into CP Angle or through foramen magnum

• Histology- perivascular rosettes and true ependymal rosettes

Osborn. Copyright Amirsys Inc 2004 http://missinglink.ucsf.edu/lm/introductionneuropathology

Ependymoma

Fill 4th ventricle like plaster cast

Extend thru the foramen of Luschka and

foramen magnum- NOT PATHOGNOMIC-

occasionally medulloblastomas also

Cystic components

frequent

Calcification

Hemorrhage

Mildly reduced

diffusion

Intraventricular

ependymomas can extend

into adjacent parenchyma

47/F 4th ventricular ependymoma with hydrocephalus

Ependymoma

Fill 4th ventricle like plaster cast

Extend thru the foramen of Luschka and

foramen magnum- NOT PATHOGNOMIC-

occasionally medulloblastomas also

47/F 4th ventricular ependymoma with hydrocephalus

Can seed through CSF (12%)

Imaging of entire neuroaxis

Subependymoma

• 0.2- 0.7 % of intracranial neoplasms

• Mostly incidental

• 50-60% in 4th ventricle

• 30-40% in lateral ventricles

• M:F= 2.3:1

• Most patients in 5th and 6th decades

• Prognosis- good

Subependymoma

• WHO grade 1 neoplasm

• Ependymal differentiation

• Well circumscribed, attached to the ventricle wall by a narrow pedicle

Osborn. Copyright Amirsys Inc 2004

Subependymoma

• Well circumscribed tumours

• Cystic change common

• Mostly no/ minimal enhancement

• Calcification may be present

• Can haemorrhage

• Unlike ependymomas- don’t extend into adjacent parenchyma, don’t seed thru CSF

Lateral ventricle subependymoma in a 44-

year-old man with a history of headaches. Smith et al 2013

Choroid Plexus Tumours

• 2-4% of pediatric brain tumours

• Most commonly child <5 years of age

• 20% of brain tumours occurring in the first year of life are Choroid plexus tumours.

• In children, 80% occur in trigone of lateral ventricle

• In adults -4th ventricle more common

• Treatment – total surgical resection

Smith et al Radiographics 2013

Choroid plexus papilloma in a 9 month old boy

Choroid Plexus Tumours

Intraventricular papillary neoplasms derived from choroid plexus epithelium

• Papilloma (CPP) WHO grade 1

• Atypical papilloma WHO grade 2

• Carcinoma (CPCa) WHO grade 3

Cauliflower like fleshy lobulated intraventricular mass

Can haemorrhage, necrosis, calcification

Hydrocephalus common- overproduction of CSF, blockage due to proteinaceous exudate, haemorrhage or direct obstruction

Smith et al Radiographics 2013

Choroid plexus papilloma in a 9 month old boy

Choroid Plexus Tumours

Enhancing intraventricular mass

Calcification 20-25%

Cysts, necrosis, haemorrhage

Hydrocephalus

CSF seeding CT-

75% iso -hyperdense

64 yr/M with instability of gait x 2 years

CPP of 4th ventricle

Choroid Plexus Tumours

• Can have CSF seeding- image the entire neuroaxis

• Difficult to differentiate CPP from CPCA on imaging alone

• Heterogeneity, brain invasion, CSF seeding favour carcinoma

Case courtesy Zoran Rumboldt

CPCa in a 1 year old child

Subependymal Giant Cell Tumour

• Intraventricular glioneuronal tumour arising near foramen of Monro

• 1.4% of all pediatric brain tumours

• Incidence of SEGA- up to 15% of patients with Tuberous sclerosis

• Enlarging enhancing intraventricular mass in a patient with Tuberous sclerosis (other findings of TS- cortical tubers, subependymal nodules)

• Probably arises from a subependymal nodule

• WHO grade 1 tumour

• No CSF seeding

Smith et al. Radiographics 2013

Subependymal Giant Cell Tumour

Case courtesy Zoran Rumboldt

Case A

Case B

Differentiated from hamartoma by interval slow

growth- needs follow up

Location Well marginated, lobulated

Heterogeneous, strong enhancement

Calcification

Obstructive hydrocephalus

Intraventricular meningioma

• 0.5%– 4% of intracranial meningiomas

• Most common location - atrium of the lateral ventricles

• Female : male = 2:1

• Peak age 30–60 years

• Uncommon in pediatric age group but higher risk of sarcomatous change Consider neurofibromatosis type 2

Intraventricular meningioma

Indolent, slow growing, large size

CT iso- to hyperattenuating

Reduced diffusion

Calcification in 50%

Cystic areas may be present

Avid enhancement

Local or diffuse ventricular dilatation -obstruction of CSF flow

Periventricular edema- transependymal CSF flow or secretion

of vascular endothelial growth factor by the meningioma

“Central” Neurocytoma

• 0.25-0.5% of intracranial neoplasms

• Lateral ventricles - may extend to 3rd ventricle- arise from septum pellucidum or lateral wall

• Wide age range, mean 29 years

• Symptoms- from raised ICP

• Usually gross surgical resection is curative

Smith et al Radiographics 2013

Central Neurocytoma

• WHO grade 2 lesions

• Gross pathology- often friable with haemorrhage or calcification

• Strong staining for synaptophysin is a diagnostic marker

Smith et al Radiographics 2013

Central Neurocytoma

• Well circumscribed, lobulated mass

• Frequently cystic changes- “bubbly” appearance

• Calcification, haemorrhage

• Hyperattenuating on CT

• Variable enhancement

30/F headaches. Central neurocytoma

Rosette-forming Glioneuronal Tumor

• Rare primary brain tumor

• WHO grade I

• Arise from progenitor pluripotential cells of the subependymal plate

• Glial and neuronal differentiation, form small neurocytic rosettes

• Young adults (mean age, 31.5 years)

• Indolent

• Present with signs of raised ICP or ataxia

• Location- fourth ventricle

• Gross total resection- curative

Smith et al Radiographics 2013

Rosette-forming Glioneuronal Tumor

• Fairly well-circumscribed

• Heterogeneous solid and cystic mass

• Classically in the fourth ventricle

• Uncommon neoplasm, considered when a cystic neoplasm of the fourth ventricle is encountered in an adult

Smith et al Radiographics 2013

62 year old lady Glioblastoma

33 year old lady with recurrent GBM

Drop metastasis in 4th ventricle

Tumours with CSF drop metastases

• Ependymoma

• Choroid plexus tumours

• Germinoma

• Medulloblastoma

• Pineoblastoma

• Ependymal invasion- GBM

Summary

• Overlapping imaging features

• Age, Tumour location

Recap

• Infant (less than 1 year) with tumour in lateral ventricles, hydrocephalus- think

Choroid plexus tumour

Recap

• Child (first 5 years) 4th ventricle plastic tumour- think

Ependymoma

Recap

• In a patient with tuberous sclerosis, foramen of Monro lesion think

Subependymal Giant Cell Tumour (SEGA)

Recap

• In elderly, a poorly or not enhancing tumour in the ventricle- think

Subependymoma

Recap

• Tumour with homogeneous enhancement , reduced diffusion- think

Meningioma

Recap

• Lateral ventricle tumour with bubbly appearance- think

Central neurocytoma

Take home message

• Diagnosis

• Extension to parenchyma

• Hydrocephalus, transependymal edema

• Ependymal enhancement

• CSF dissemination

Imaging of the whole neuroaxis

Thank you