brain tumor

Presented By Dr. Shamim RimaM.PHILRADIOLOGY & IMAGINGBSMMU.

BRAIN TUMOUR

• Cerebral tumours are predominantly tumours of adult life With a peak incidence of 13 cases per 100,000 population at age 55-65.• They are relatively uncommon in infants and children at 2 cases per 1,00,000.

• Primary neoplasms of the central nervous system (CNS) represent nearly 10% of all tumour reported.

Age Incidence

Primary Tumour

Primary intracranial tumour can occur at any age, it is helpful in deferential diagnosis to know that certain tumor occur mainly in certain age groups.

BRAIN TUMOUR, Contd.

Secondary Tumour

These affect mainly the middle aged and elderly, with the exception of secondary neuroblastoma which occurs mainly in children.

Location• In adults supratentorial tumours out number posterior fossa tumour by a ratio of 7 to 3.• But in children this ratio is reversed and posterior fossa tumours are the most common.

BRAIN TUMOUR, Contd.

• The goals of diagnostic imaging in the Pt. with suspected

intracranial tumour include:

- - Detection of the presence of neoplasmDetection of the presence of neoplasm

- Localization of the extent of the tumour- Localization of the extent of the tumour

- Characterization of the nature of the process- Characterization of the nature of the process

DIAGNOSTIC IMAGING

Contd ..

Plain radiography :Plain radiography : Full skull series include the Full skull series include the four viewsfour views

- - Lateral projection Lateral projection - Occipito frontal projection - Occipito frontal projection - Half axial antero posterior (Town’s) - Half axial antero posterior (Town’s)

Projection Projection - Sub mento vertical (base) Projection - Sub mento vertical (base) Projection

DIAGNOSTIC IMAGING

Contd ..

DIAGNOSTIC IMAGING:

CT- Routine CT examination of the brain and specific area. - Computed tomography cisternography.

MRI - Magnetic resonance diffusion imaging - Magnetic resonance perfusion imaging. - Magnetic resonance spectroscopy.

Contd ..

DIAGNOSTIC IMAGING:

Contd ..

Functional Imaging techniques

- Single photon emission computed tomography- Positron emission tomography

Vascular Imaging

- Conventional intra arterial angiography - Computed tomography angiography - MR angiography- Doppler ultrasound

CLASSIFICATION• Brain tumour may be classified in different ways one of them may be:

Primary neoplasm that derived from normal cellular constituents

Primary neoplasm that arise from embryologically misplaced tissue

Secondary neoplasm from extracranial primary sites that metastasize to the CNS.Non neoplastic condition that can mimic tumour.

Contd ..

CLASSIFICATION OF INTRA CRANIAL TUMOURS:

primary versus secondary

intraxial (arising from the brain parenchyma) versus extra axial (arising from tissue covering the brain such as dura) andvarious regional classification

There are several ways of classifying brain tumours:

> Supratentorial > Infratentorial> Intraventricular > Pineal region> Sellar region tumours. Contd ..

CLASSIFICATION ACCORDING TO HISTOLOGY

Primary brain tumours are subdivided into two basic groups:

Tumours of neuroglial origin (Glioma)

Non - glial tumours that are specified by a combination of putative cell origin and specific location.

Glial tumors (gliomas)

- Astrocytomas

Fibrillary astrocytomas

Benign astrocytomaContd ..

GLIAL TUMORS (GLIOMAS)

Astrocytomas :Anaplastic astrocytomaGlioblastoma multiforme

Pilocytic astrocytomaPleomorphic xanthoastrocytoma

Subependymal giant cell astrocytoma

Oligodendroglioma

Ependymal tumours

Choroid plexus tumours Contd ..

NONGLIAL TUMOURS

Neuronal and mixed neuronal-glial tumours

Ganglioglioma Gangliocytoma

Meningeal and mesenchymal tumours

Meningioma

Hemangiopericytoma

Hemangioblastoma

Fibrous histiocytoma Contd ..

NONGLIAL TUMOURS

Pineal region tumours

Germ cell tumours

Germinoma

Teratoma Choriocarcinoma Pineal cell tumoursPineoblastoma Pineocytoma

Contd ..

Nonglial tumours

Other cell tumoursOther cell tumours

Benign pineal cysts Benign pineal cysts Astrocytoma

Embryonal tumoursEmbryonal tumours

Neuroblastoma Neuroblastoma Primitive neuroectodermal tumours Primitive neuroectodermal tumours (PNET)(PNET)

SchwannomaSchwannomaNeurofibroma Neurofibroma

Cranial and spinal nerve Cranial and spinal nerve tumours tumours

NONGLIAL TUMOURS

Hemopoetic Hemopoetic neoplasm's neoplasm's

Lymphoma Lymphoma Leukemia Leukemia Plasmacytoma Plasmacytoma

Pituitary tumoursPituitary tumours

Contd ..

NONGLIAL TUMOURS

Cysts and tumour like lesions

Rathke cleft cyst Dermoid cyst Epidermoid cystColloid cyst Enterogenous cystNeuroglial cystLipoma Hamartoma Contd

..

NONGLIAL TUMOURS Contd.

Local extensions from regional tumoursCraniopharyngiomaParaganglioma

Chordoma

According to location

Intra axial

Extra axial

PointsPoints Intra axialIntra axial Extra axialExtra axial

LocationLocation Within brain Within brain parenchyma.parenchyma.

Outside brain Outside brain parenchymaparenchyma

Contiguity with bone / Contiguity with bone / flaxflax Usually notUsually not YesYes

Bony changesBony changes Usually notUsually not YesYes

CSF spaceCSF space EffacedEffaced Often widenedOften widened

Corticomedullary Corticomedullary bucklingbuckling NoNo YesYes

GM / WM junctionGM / WM junction DestructionDestruction PreservationPreservation

Vascular supplyVascular supply Internal carotid Internal carotid arteryartery

External carotid External carotid arteryartery

INTRA AXIAL

Primary

GliomaAtrocytomaOligodendrogliomaEpendymal tumourLymphoma

HemangioblastomaDermoid , epidermoid (rarely)

Secondary

Metastesis

INTRA AXIAL Contd.

Infratentorial

• Brainstem glioma• Cerebellar astrocytoma• Medulloblastoma• Ependymoma• Meningioma• Hemangioblastoma• Dermoid

INTRA AXIAL Contd.

Supratentorial

• Meningeoma• Dermoid• Epidermoid• Pitutary adenoma• Pineal region tumour• Craniopharyngeoma• Chordoma

INTRA AXIAL Contd.

Infratentorial

• Acoustic neuroma• Meningioma• Dermoid• Chordoma• Glomus jugular tumour

OTHER CLASSIFICATION

Pediatric brain tumour

Brain stem gliomaOptic pathway

gliomaMedulloblastoma

CraniopharyngiomaNeuroblastoma

Cerebellar astrocytomaEpendymoma

OTHER CLASSIFICATION

Intraventricular tumour

Ependymoma

Choroid pluxus tumor

Colloid cystsMeningioma

CLASSIFICATION – ACCORDING AGE GROUP

YEARSYEARS CLASSIFICATIONCLASSIFICATION

0-50-5 Brain Stem Glioma, Optic Nerve GliomaBrain Stem Glioma, Optic Nerve Glioma

5-155-15Medulloblastoma, Cerebellar Astrocytoma, Medulloblastoma, Cerebellar Astrocytoma, Craniopharyngma, Choroid Plexus Papiloma Craniopharyngma, Choroid Plexus Papiloma , Pinealoma., Pinealoma.

15-3015-30 EpendymomaEpendymoma

30-6030-60 Glioma, Meningioma, Acoustic neuroma, Glioma, Meningioma, Acoustic neuroma, Pitutary Tumour, HemangioblastomaPitutary Tumour, Hemangioblastoma

60+60+ Meningeoma, Acoustic Neuroma, Meningeoma, Acoustic Neuroma, GlioblastomaGlioblastoma

CLASSIFICATION ACCORDING TO FREQUENCY

FREQUENCYFREQUENCY CLASSIFICATIONCLASSIFICATION

AdultAdultGlioma, Metastasis, Meningioma, Glioma, Metastasis, Meningioma, Pitutary Tumour, Pitutary Tumour, Hemangeoblastoma, LymphomaHemangeoblastoma, Lymphoma

ChildChildAstrocytoma, Medulloblastoma, Astrocytoma, Medulloblastoma, Ependymoma, CraniopharyngiomaEpendymoma, Craniopharyngioma

FREQUENCY OF CEREBRAL TUMOURS

TumourTumour FrequencyFrequency

Gliomas Gliomas 31.431.4

Metastases Metastases 20.320.3

MeningiomasMeningiomas 15.415.4

Angiomas Angiomas 5.95.9

PituitaryPituitaryAdenomas Adenomas

4.44.4

AcousticAcousticTumours Tumours

1.51.5

Congenital Congenital Tumours Tumours

2.02.0

Miscellanous Miscellanous 12.312.3

TUMOUR OF NEUROEPITHELIAL TISSUE

Glioma

Tumours arising from neuroglial cells known as gliomas are most common intracranial brain tumour which comprises 45%- 65% in a series2/3rd of all brain tumours are primary neoplasm

Almost ½ of all brain tumours are glioma¾ th of all gliomas are astrocytic

> ¾ th of all astrocytomas are anaplastic and GBM

ASTROCYTIC TUMOUR

Circumscribed Astrocytoma

Juvenile pilocytic astrocytomaPleomorphic xanthoastrocytomaSubependymal giant cell astrocytoma

Low grade astrocytomaAnaplastic astrocytoma

Diffuse

Glioblastoma multiformeGliomatosis cerebriGliosarcoma

WHO CLASSIFICATION

GRADEGRADE CLASSIFICATIONCLASSIFICATION

Grade 1 Grade 1 Pilocytic astrocytomaPilocytic astrocytomaSGCA(subependymal giant cell SGCA(subependymal giant cell astrocytoma)astrocytoma)

Grade 2 Grade 2 Low grade astrocytomaLow grade astrocytoma

Grade 3Grade 3 Anaplastic astrocytomaAnaplastic astrocytoma

Grade 4Grade 4 Glioblastoma multiformeGlioblastoma multiforme

FEATURES OF LOW GRADE GLIOMA

Age – Younger age group 20-40 yrs

Incidence – 10-20% of astrocytoma

Location – cerebral hemisphere frontal and parietel lobe temporal lobe

Histology- low grade malignancy

Presenting Symptom - Seizure

IMAGING STUDY LOW GRADE GLIOMA

CT

NECT : Iso/hypo CECT : Little or no enhancement


MRI

T1 : Iso/HypointenseT2 : Homogenously hyper

Fluorodeoxyglucose usually shows reduced uptake compared to the rest of the brain, indicative of hypometabolism


PET scan

IMAGING STUDY LOW GRADE GLIOMA.

Others

No perilesional oedema

No haemorrhage

Mild to moderate mass effect

Most are eventually under go malignant degeneration

Calcification occurs in 15-20 % cases

ANAPLASTIC ASTROCYTOMA

It usually occurs in the middle aged patients

Incidence- 20-25% Locations: cerebral hemispheres frontal and temporal lobe

Histology- malignant

Presenting Symptom- Seizure, focal neurological deficit

CT

IMAGING STUDY ANAPLASTIC ASTROCYTOMA

NECT : Iso/hypo In homogenous mixed density

CECT : Enhance strongly, inhomogenously


MRI

T1: Hypo to iso intenseT2 : Heterogenously Hyperintense

As typically enhance strongly but non uniformly following contrast administration. Irregular rim enhancement is common

Calcification – uncommonOedema- perilesional oedema commonHaemorrhage may occurCystic area may present

Mass effect CommonHistologically malignant

OTHER FEATURES


GLIOBLASTOMA MULTIFORME

Half of all astrocytoma are GBM. It is most common supratentorial neoplasm in adult. The most common primary brain tumour, it is also the most malignant astrocytoma

Incidence – 40-50%.Age- > 50yrs. Locations- cerebral hemisphere, Frontal

and temporal lobe, White mater Presenting symptom- Seizure, Focal

neurological deficit, stroke like syndroms

Median survival is 8 months after operation.

Infratentorial glioblastoma multiforme is rare and often represents subarachnoid dessimination of supra tentorial origin.

Natural history- spreads rapidly and diffusely

Prognosis- worst prognosis

GLIOBLASTOMA MULTIFORME,cont

IMAGING STUDY

CT

NECT : In homogenously mixed density lesionCECT : Enhances strongly, inhomogenously. Ring enhancing lesion – due to increased cellularity and neovascularity. Area of central necrosis shows hypodensity

Imaging study shows ‘multiforme’ appearance

MRI

T1: T1 weighted image shows mixed signal mass with necrosis or cyst formation and thick irregular wall.Marked but in homogenous contrast enhancement is present in majority of glioblastoma multiforme. These tumours are hihgly vascular, haemorrhage of different ages are often present.

T-1 T-1 C T-1 C

MRI

T2: T2- weighted image shows very heterogenous mass with mixed signal intensity. Central necrosis is the hall mark. Haemorrhage , necrosis, oedema are present in GBMAngiograp

hyA large mass with striking tumours blush, Contrast stasis and pooling in Bizarre vascular channel is typical

Other features

Calcification uncommonOedema abundantMass effect more severeHaemorrhage common

IMAGING STUDY Contd.

IMAGING STUDY Contd.

Spread

Through white materSub ependymal seedlingThrough CSFRarely through haemtogenous routeExtra cerebral metastasis- Lung, Liver, Bone

PILOCYTIC ASTROCYTOMA

This tumour is of grade –I of WHO grading

Age -most commonly affects the patients in the 2nd decadeof lifeSite - 2/3rd of pilocytic astrocytoma occurs in cerebellum. 25-30% in the region of optic nerve , chisma, hypothalmus. Remainder in the cerebrum.

Generally have benign course because of their lack of invasion and lack of malignant degeneration

Better prognosis than infiltrating fibrillary and diffuse astrocytoma.

Elongated and fibrillated cells often associated with Rosenthal fiberEosinophilic granular body commonMicrocystic area alternate with pilocytic area

Pathology

IMAGING STUDY

CT

Slightly hypodese to isodenseWell-definend core in >50%Cystic componentMural nodule with contrast enhancementCalcification seen in 22% cases Very little or no oedemaMass effect present –displaces or compresse 4th ventricle

MRI

Sharply defined macrocystic mass Mural nodule easily identifiablePronounced contrast enhancement

PILOCYTIC ASTROCYTOMA IMAGING STUDY

OLIGODENDROGLIOMA

Arise from a specific type of glial cell- Oligodendrocyte. These are typically unencapsulated but well circumscribed focal white matter tumours that may extent into the cortex and leptomeninges. Foci of cystic degeneration common Hge, necrosis uncommon

Incidence - 5-10% of gliomasAge distribution- 4th to 5th decadePeak age - 35-45 yrs. Location - 85% supratentorial Cerebral hemisphere- mostly frontal

X-RAY

Show characteristic serpigineus calcification.

IMAGING STUDY

IMAGING STUDY- OLIGODENDROGLIOMA

CT NECT- Prominent mass of calcification. Partially calcified mixed density hemispheric mass that extends peripherally to the cortex.

CECT- Mild to moderate contrast enhancement occurs

MRIHeterogenous signal intensity due to calcificationT1- weighted image shows mixed hypo or iso intensity lesionT2- weighted image shows hyper intense foci Absent to slight enhancement is typical

T-1 T-1 C T-2



Other features

Calcification- occurs in 70-90%, peripherally located, clumped nodules Cysts are common Oedema relatively rarePeritumoural oedema and contrast enhancement is more common in anaplastic astrocytoma

Histological feature shows ‘fried egg’ appearance

EPENDYMOMA

Ependymomas are tumours of the young and are third most common intracranial tumour of children

Age distribution- 1-5 yrs. Incidence- 2-8% of gliomas 15% of pediatric brain tumourLocation- 60% infratentorial more common in children. 40% supratentorial more common in adult. 4th ventricle, C-P angle, in or near 3rd ventricle

IMAGING STUDY- EPENDYMOMA

CT

NECT- Mixed density, isodense or slightly hyperdenseFine calcification seen in approximately 50% of

the patients. May have cystic areas

CECT- More than 80% contrast enhancement occurs

MRI

T1- Heterogenous signal intensity markedly hypointense area due to calcification In homogenous enhancement with gadolinium T2- Iso to hyper intensity

Histological feature shows uniform ependymal cells in pattern of rosettes, canal or perivascular pseudorosettes

IMAGING STUDY- EPENDYMOMA

Other features:Other features:Hydrocephalus if in posterior fossa.Hydrocephalus if in posterior fossa.Fine calcificationFine calcificationHeadache, nausea, vomiting, papilledema are Headache, nausea, vomiting, papilledema are most common presentationmost common presentation

CHOROID PLEXUS PAPILLOMACHOROID PLEXUS PAPILLOMA

Tumours of choroid plexus are rare, accounting for 0.4-Tumours of choroid plexus are rare, accounting for 0.4-0.6% of all intracranial tumour0.6% of all intracranial tumour

Age distribution- > 85% occurs in childrenAge distribution- > 85% occurs in childrenLocation Location in case of childrenin case of children majority of the majority of the choroidchoroid plexus tumour occurs in plexus tumour occurs in lateral lateral ventricleventricle In adult In adult most of the choroid plexus most of the choroid plexus papilloma occurs in papilloma occurs in 4th ventricle4th ventricle

IMAGING STUDY CHOROID PLEXUS IMAGING STUDY CHOROID PLEXUS PAPILLOMAPAPILLOMA

CTCT

NECTNECT Iso or hyperdense, 3/4th hyperdense Iso or hyperdense, 3/4th hyperdenseCECTCECT heterogenous contrast enhancement heterogenous contrast enhancement

MRIMRI

T1T1 weightedweighted image shows- Predominently image shows- Predominently isointenseisointenseIntensely contrast enhancement Intensely contrast enhancement

occursoccursT2T2 weighted image shows- Iso to hyperintense, weighted image shows- Iso to hyperintense, occasionally signal void from the vascular occasionally signal void from the vascular pediclepedicle

IMAGING STUDY CHOROID PLEXUS IMAGING STUDY CHOROID PLEXUS PAPILLOMAPAPILLOMA

Other features

Calcification occurs in 25% casesHydrocephalus severeDrop metastasis common

The imaging differential diagnosis of choroid plexus papillomaIn a child CPCs

papillary ependymomamedulloblastoma

astrocytomaIn adult patient meningiom

ametastasis

IMAGING STUDY CHOROID PLEXUS PAPILLOMAIMAGING STUDY CHOROID PLEXUS PAPILLOMA

rostrally by the posterior part of 3rd ventricle and

PINEAL TUMOUR

The pineal region is defined as the area of the brain bordereddorsally by the splenium of corpus callosum and the tela choroidea

ventrally by the quadrigeminal plate and midbrain tectum

caudally by the cerebellar vermis

PINEAL TUMOUR , Cont

The pineal region tumours are rare tumour the incidence of which is 1% of all intra cranial tumour.

Gemcell tumour

Pineal cell tumour

GerminomaTeratomaEmbryonal carcinoma Choriocarcinoma

PinealoblastomaPinealocytoma

Types of pineal region tumour are as follows

PINEAL TUMOUR , Cont

Tumour of supporting cells and adjacent structure

Metastic tumour in the pineal region

AstrocytomaMeningiomaBenign pineal cystHaemangiomaCraniopharyngioma

GERMINOMA

This type of germ cell tumour is most common in the pineal region

Incidence 65-72% of all intracranial germ cell tumourAge distribution 10-30yrs

Consistency is mainly solid, cystic may be present

Radiological studyCT: NECT- slightly hyperdense Engulfment or displacement of pineal gland is found CECT- Enhancement occurs strongly and uniformly

MRI

Other featuresNoncapsulated.Tends to grow slowly by invasion. More radiosesitive.Ependymal spread more common.

Nonspecific or variable

GERMINOMA RADIOLOGICAL STUDY

T2 heterogenous slight hyperintensity

homogeneous masses with signal intensity equal to that of gray matter

homogenous post gd enhancement T1 hyperintense

Teratomas derives from all germ layer.These tumour occur mostly in children below 9yrs. Usually within 1st two decade. Origin - two or more germ layers.Age – Children . Male predominance.Imaging study : CT scan- heterogeneous lesion Contrast CT- Little or no contrast enhancement

Irregular margin MRI- Nonspecific findings Teratoma may be – Mature teratoma Immature teratoma Teratoma with malignant transformation.

TERATOMA

PINEO BLASTOMA

This tumour ( PNET) is highly malignantAge distribution -1st and 2nd decade

Haemorrhage, calcification, necrosis are common in this type of tumour. Pineoblastoma disseminate through CSFHistologically similar to medulloblastoma and retinoblastoma

Imaging study CT hyper dense lesion contrast enhancement occurs densely

MRIT 1 weighted image shows hypointenseT 2 weighted image shows mixed intensity

SELLAR/SUPRASELLAR MASSES

The sellar region is an anatomically complex area composed of the bony sellaturcica, pituitary gland, and adjacent structures

Older classification Chromophobic Acido philic Basophilic Mixed New classification

Pituitary microadenoma (size <10mm)

Pituitary macroadenoma (size >10mm)

Pituitary adenoma

Pituitary adenoma is benign slow growing neoplasm.It arises from adenohypophysis (anterior pituitary). Age and sex- more in adult ( < 10% in children)Microadenomas are more common than macroadenomaPituitary adenoma 75% are endocrinologically active

25% are nonfunctioning, formerly called ‘nonfunctioning tumour’or chromophobe adenoma, they are now called null cell adenoma or oncocytoma.

PITUITARY ADENOMA

FUNCTIONING PITUITARY TUMOUR

ProlactinomaSomatotrophic tumour(GH secreting)

Corticotrophic tumour( ACTH secreting)MixedOthers

Radiological featuresArea of haemorrhage, necrosis, cyst formation are less commonRI is the most sensitive imaging study for pituitary tumour

T 1 weighted image (non contrast) showshypointense to pituitary gland

gland becomes asymmetricgland becomes covex superiorlystalk deviation occursdepression of sellar floor

RADIOLOGICAL FEATURES

After contrast (GD- DTPA) dynamic image is requiredAfter contrast (GD- DTPA) dynamic image is requiredRapid sequence coronal single slice of T 1 weighted Rapid sequence coronal single slice of T 1 weighted image of sella immediately after I.V. bolus image of sella immediately after I.V. bolus administration of contrast with image obtained administration of contrast with image obtained consecutively of 10 second interval upto 3 minutes.consecutively of 10 second interval upto 3 minutes.

Hypo intense tumour over 1st 1-2 minute after injectionHypo intense tumour over 1st 1-2 minute after injectionOn delayed film may mask the presence of tumourOn delayed film may mask the presence of tumourT2 weighted image shows focal mild hyper intensityT2 weighted image shows focal mild hyper intensity

PITUITARY MACROADENOMAPITUITARY MACROADENOMA

This type of tumour is usually endocrinologically inactiveThis type of tumour is usually endocrinologically inactiveIncidence- 70-80% ie twice as common as Incidence- 70-80% ie twice as common as microadenomamicroadenomaAge distribution of pituitary macroadenoma- 4th to 5th decade of Age distribution of pituitary macroadenoma- 4th to 5th decade of lifelife

Pituitary macroadenoma becomes symtomatic because Pituitary macroadenoma becomes symtomatic because of their mass effect- hypo pituitarism, visual problems of their mass effect- hypo pituitarism, visual problems etcetcMacroadenoma secrets hormone sub unit, so clinically Macroadenoma secrets hormone sub unit, so clinically inactiveinactive

IMAGING STUDY

X-rayexpansion of sellar cavitythining of bony cortexballooning of sella

CT

Large, homogenously isodense, rounded midline mass

ExtensionInto the suprasellar cystern forming the figure of eight(8 )Elevate and compress the optic chiasma and 3rd ventricleLaterally into the cavernous sinusMay encase the ICA or narrow the vesselsArea of haemorrhage, necrosis, cyst formation are common which appear as hypodense within the tumourAcute or subacute haemorrhage causes focal intratumoural hyperdense area

Hydrocephalus due to obstruction of foramen monro may occurCalcification is rare

PITUITARY MACROADENOMA, PITUITARY MACROADENOMA, ContCont

Both CT and MRI show strong contrast enhancement with some what inhomogenously

MRI

T 1 weighted image shows hypointense

T 2 weighted image shows hyperintensity

Extension is better visualized after contrast

MENINGEAL AND MESENCHYMAL TUMOUR

MeningiomasMalignant mesenchymal tumourHemangiopericytomaHemangioblastoma

Meningiomas are most common nonglial primary brain tumourMost common extra axial tumour (13-18%)Age – adult tumour 40-60yrsSex- more in femaleCytogenetics-chromosome 22 is important for pathogenesis of meningioma

Meningiomas

Neurofibroma type –II is the major predisposing factor for meningioma

MENINGIOMAS

Origin; Meningioma arises from arachnoid cap cellsIn children - > 10% becomes multiple

WHO classificationTypical 88-95%Atypical 5-7%Anaplastic 1-2%

Typesglobular, flat, compact rounded with invagination of brainMeningioma enplaqueMulti centric /multifocal

Location Cerebral convexity 32-45 %

Parasagital 26%

Sphenoid ridge 20 % Juxtra sellar

10 %

olfactory groove 10 %

Posterior fossa 10 %

Tentorium

Pineal region

Others optic nerve sheath, intravetrricular

IMAGE STUDYIMAGE STUDY

X-rayX-rayHyperostosisHyperostosisErosionErosionEnlarged vascular Enlarged vascular channelschannelsTumourTumour calcificationscalcificationsPneumosinusPneumosinus dilatansdilatans


CTCT

70% to 75% hyperdense70% to 75% hyperdense20% to 25% calcified20% to 25% calcified90% enhance strongly , uniformly90% enhance strongly , uniformly

10% to 15% cystic areas10% to 15% cystic areas60% peritumoral 60% peritumoral edemaedemaHemorrhage Hemorrhage rarerare

Area of haemorrhage, necrosis, cyst formation are Area of haemorrhage, necrosis, cyst formation are common which appear as hypodense within the tumourcommon which appear as hypodense within the tumour


AngiographAngiographyyDual vascular supply commonDual vascular supply commonSunburst of enlarged dural feeders in tumourSunburst of enlarged dural feeders in tumour

ExtensionExtensionInto the suprasellar cystern forming the figure of eight(8 )Into the suprasellar cystern forming the figure of eight(8 )Elevate and compress the optic chiasma and 3rd ventricleElevate and compress the optic chiasma and 3rd ventricle

Laterally into the cavernous sinusLaterally into the cavernous sinusMay encase the ICA or narrow the vesselsMay encase the ICA or narrow the vessels

Area of haemorrhage, necrosis, cyst formation are common which appear as hypodense within the tumourAcute or subacute haemorrhage causes focal intratumoural hyperdense area

Hydrocephalus due to obstruction of foramen monro may occur.Calcification is rareMRI

T 1 weighted image shows hypointense

T 2 weighted image shows hyperintensity. Extension is better visualized after contrast.

IMAGE STUDYIMAGE STUDY -MENINGIOMAS

Both CT and MRI show strong contrast enhancement with some what in homogenously

Other features:Other features: Cystic degeneration may present,Cystic degeneration may present,

Calcification, haemorrhage, Calcification, haemorrhage, Rotational deformity of brain stem, Rotational deformity of brain stem, Present with features of extra axial mass Present with features of extra axial mass

Neurofibroma:Neurofibroma: Schwann cell and fibroblast origin,Schwann cell and fibroblast origin, Noncapsulated, Noncapsulated, Infiltrating, fusiform Infiltrating, fusiform,,


- Schwannoma- Neurofibroma- Malignant nerve sheath tumour

Nerve Sheath Tumour

SchwannomaBenign tumour of schwann cell origin related to cranial nerves. -90% are solitary-Multiple Schwannoma are associated with neurofibromatosis type 290% of intracranial schwannomas are located in the cerebello pontine angle originating from VIII cranial nerve- acoustic neuroma.Age- 40-60 yrs.Sex- female preponderance

All the cranial nerves except olfactory and optic nerve, are partially composed of schwann cells so are potentially site for schwannomaMost arises at the site where axonal sheath switches from glial to schwanncell origin

Most common – vestibular schwannoma, Trigeminal nerve schwannoma

Other intracranial sites- infratemporal, jugular foramen and bulb. Clinical feature depends upon specific nerve involvement and sizeVestibulo-cochlear nerve- Tinnitus, sensory neural hearing impairment

Trigeminal nerve- Facial sensory impairment, ataxia, exoph thalmos, diplopia, corneal reflex loss

RADIOLOGICAL STUDY

Mass causes >2 mmdifference between right and left I.A.C (Internal acoustic canal)

Erosion and flattening of I.A.C.I A C > 8mm

CTNECT - Is to slight hypodense

CECT – Small tumour uniformly enhances

MRI

More sesitive than CT

T 1 weighted image- 2/3rd slightly hypointense, 1/3rd iso intense

RADIOLOGICAL STUDY

T 2 weighted image – mild to markedly increased signal intensity. After contrast- intense enhancementHomogenous- 62% smallHeterogenous- 22% large

Extension of cerebello pontine angle tumopur into IAC causes ‘cone ice cream’ appearance

RADIOLOGICAL STUDY

Cystic degeneration may present,Calcification, haemorrhage,Rotational deformity of brain stem,Present with features of extra axial mass

Other Features

Neurofibroma

Schwann cell and fibroblast origin,Noncapsulated,Infiltrating, fusiform

Point Point Schwannoma Schwannoma NeurofibromaNeurofibroma1. 1.

PathologPathology y

Schwann cell origin Schwann cell origin Encapsulated Encapsulated Focal, Round Focal, Round Cyst, Hge, necrosis-Cyst, Hge, necrosis-

commoncommonMalignant Malignant

degeneration –not degeneration –not

Schwann cell + Fibroblast Schwann cell + Fibroblast Uncapsulated Uncapsulated Infiltrating, Fusiform Infiltrating, Fusiform Rear Rear Malignant degeneration- Malignant degeneration-

5 to 10%5 to 10%

2. 2. ssociatiossociation n

NF2 NF2 NF1NF1

3. Incidence 3. Incidence Common Common Uncommon Uncommon 4. Age 4. Age 40-60 Yrs 40-60 Yrs Any age Any age 5. Location 5. Location Cranial nerve esp. Cranial nerve esp.

CN VIII CN VIII cutaneous and spinal cutaneous and spinal

nervenerve6. Imaging 6. Imaging Sharply delineated Sharply delineated

Heterogenous Heterogenous TT11-70% -Hypo -70% -Hypo 30% -ISO intense 30% -ISO intense TT22- Hyper intense - Hyper intense Enhancement- strong Enhancement- strong

Poorly delineated, Poorly delineated, infiltrating infiltrating

Homogenous Homogenous TT11- mostly ISO intense - mostly ISO intense TT22- Hyper intense - Hyper intense Enhancement- moderateEnhancement- moderate

CEREBELLOPONTINE ANGLE (CPA) CISTERN MASSES

Normal AnatomyThe cerebellopontine angle (CPA) cistern between the anterolateral surface of the pons and cerebellum and the posterior surface of the petrous temporal bone. Important structures within the CPA cistern include the fifth, seventh, and eighth cranial nerves, the superior and anterior inferior cerebellar arteries, and tributaries of the superior petrosal veins


Normal Anatomy

The majority of CPA tumours in adults are extraaxial. Imaging findings that distingush extraaxail from intraaxail masses include the following: 1.Enlarged CPA cistern. 2.A CSF cleft between the mass and adjacent brain . 3. Brainstem rotation. 4. Displaced cerebellar hemisphere cortex.

Common CPA masses

- Vestubular schwannoma (acoustic neuroma) - Meningioma - Epidermoid - Other schwannoma

Less common

- Arachnoid cyst - Metastases - Vascular - Lipoma

- Dermoid.


Intraventricular Tumour

One tenth of all CNS tumour involve the ventricle. Imaging characteristics are usually nonspecific; exact location of the mass and age of the patients are the most helpfull information in the diagnosis of these lesions


INTRAVENTRICULAR MASSES IN ADULT

In Lateral Ventricle - Astrocytoma(anaplastic, glioblastoma) - Central neurocytoma. - Subepedymoma. - Oligodendroglioma. - Choroid plexus papilloma. - Meningioma. - Metastases

Foramen Of Monro/Third Ventricle

- Colloid cyst- Central neurocytoma- AstrocytomaExtrinsic mass- pituitary adenoma, aneurysm, germinoma

INTRAVENTRICULAR MASSES IN ADULT

Aqueduct/Fourth Ventricle

- Midbrain glioma- Metastases- Subependymoma- Haemangiblastoma

INTRAVENTRICULAR MASSES IN CHILDREN

1. Lateral ventricleChoroid plexus tumour.PNETAstrcytomaEpendymoma

2. Third ventricle.CraniopharyngiomaSubependymomaGerminoma

3. Fourth ventriclePylocytic astrocytomaMedulloblastomaEpendymomaExophytic tumour

Aqueduct/Fourth Ventricle

- Midbrain glioma- Metastases- Subependymoma- Haemangiblastoma

COLLOID CYST

A cystic tumour arising from an embryological remnant in the anterior roof of 3rd ventricle.It is neuro epithelial cyst comprises 2% of all glioma and 0.5-1% of all intracranial tumour.Site- most commonly found in the 3rd ventricle but may in septum pellucidum.Age- usually 20-50 years. Pathogenesis- comprises of fibrous epithelial lined wall filledwith either mucoid or dense hyaloid substance.Colloid cyst is slow growing, benign tumour. It blocks the foramina of Monro causing obstructive hydrocephalus involving only the lateral ventricle. Although it is a slow growing benign tumour, there is risk of sudden death.

Presentation

COLLOID CYST

Most commonly presents with intermittent acute intracranial hypertension due to episodic obstruction of foramen Monro.Most clinically significant cysts are > 1.5 cm in diameter. Sudden death may occur due to acute blockage of C.S.F flow resulting herniation

Radiological Findings

Lesion is situated in the anterior 3rd ventricle causing obstruction of foramen of Monro and dilatation of lateral ventricle

COLLOID CYST

CT Scan Of Brain

Findings are variable. Most cysts are hyper dense ( 2/3rd ),1/3rd are isodense. A well delineated round or ovoid non calcified anterior 3rd ventricular mass. Enhancement, following contrast administration is usually absent.M.R.I.

The most common appearance is a mass that is hyperintense on T1 and hypointense on T2. The signal intensity of colloid cyst vary widely. Rim enhancement on contrast administration is observed in some cases

COLLOID CYST

Rathke Cleft Cyst

Etiology

Primitive stomodial remnant(Rathke pouch). Pathology:Cyst with variable contents. Columnar, cuboidal or squamous epithelium

Age and gender

Any age but mostly adult. Female: Male 2-3: 1.

Location

70% both intra sellar and suprasellar, 20-25% intrasellar and <5% completly suprasellar

MEDULLOBLASTOMA

Most common malignant pediatric brain tumour.Incidence: 15-20% of intracranial tumour in children. Male: Female 2:1.Age: most in 1st decade. 75% in 4-8 years. Site: 75% arises in the cerebellar vermis mostly in midline, in the apex of 4th ventricle. 25% arises in lateral cerebellum.Highly radiosensitive and moderately chemo sensitive.

Metastasis occur early in the CSF. Prognosis is very poor

MEDULLOBLASTOMA

Radiological study

CT scan of brain:Rounded or ovoid, mainly homogenous iso to slightly hyper dense mass. Obstructive hydrocephalus is common. calcification occurs in 15% patients

Moderately strong, relatively homogenous enhancement is seen following contrast administration. Typical medulloblastoma fills the 4th ventricle and extends through foramen of Magendie in to the cysterna magna. T 1 weighted image shows heterogeneous hypointense, cyst in 75-80%.T 2 weighted image shows hypo to hyper intense. Contrast enhancement is variable. Moderately enhancement which is heterogeneous in nature. Many medulloblastoma shows partial enhancement following contrast administration.

CRANIOPHARYNGIOMA

Craniopharyngiomas arise from the squamous epithelial rests along the involuted hypophyseal Rathke’s duct.Incidence: 3-5% of primary brain tumour. 50% of pediatric brain tumour. Age: > 50% in children, peak between 8-12 years. Location: 70 % combined suprasellar and intrasellarImaging study

CT scan of brain- 90% partially cystic,90% calcification present,90% nodular or rim enhancement occur

MRI of BrainVariable signal, most common is hypointense in T 1 weighted image and hyperintense in T2 weighted image

INTRACRANIAL METASTASES

Representing 1/4th to 1/3rd of all brain tumour. Common: Skull Leptomeninges Parenchymal (most common).Less common:

Dural Pial Sub pial

Parenchymal metastases:Location – any where but most common in cortico medullary junction ( grey mater- white mater interface).


Pathology

Welldefined circumscribed nodule of variable size May be solid partially cystic, filled with mucinous material, necrotic material, haemorrhagic fluid.

Imaging Study

CT:NECT- mostly isodense lesion / hyperdense lesion- Example-Thyroid carcinoma, Lung carcinoma,choriocarcinoma, malignant melanoma, sarcoma

Cystic metastasis


Mucin producing tumour adenocarcinoma arising from stomach, small and large intestine, pancreas, ovary,breast cancer

Cystic and calcified metastasis

Rare- breast carcinoma, lung cancer. CECT:Most enhance strongly, both solid and ring shaped pattern are noted

MRI

T 1 weighted image-shows variable features most non haemorrhagic tumour slightly hyper intense.Some non haemorrhagic tumour – hyper intense

MRI


T 2 weighted image - Most are hyper intense with iso intense rimSome are hypointense on T 2 W image mucin secreting tumour from adenocarcinoma of G I T. After contrast, most enhances strongly.

Solid, rim, mixed enhancement are seen.High dose contrast (0.2-0.3 mmol/kg) normal 0.1 mmol/kg more sensitive and helpful for identification of early, small, additional foci.

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