2. 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
3. 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.
4. 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.
5. • 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 ..
6. Plain radiography :Plain radiography :
Full skull series include theFull skull series include the four viewsfour views
-- Lateral projectionLateral projection
- Occipito frontal projection- Occipito frontal projection
- Half axial antero posterior (Town’s)- Half axial antero posterior (Town’s)
ProjectionProjection
- Sub mento vertical (base) Projection- Sub mento vertical (base) Projection
DIAGNOSTIC IMAGING
Contd ..
7. 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 ..
9. 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 ..
10. 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) and
various regional
classification
There are several ways of classifying brain tumours:
> Supratentorial
> Infratentorial
> Intraventricular
> Pineal region
> Sellar region tumours. Contd ..
11. 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 astrocytoma
Contd ..
18. NONGLIAL TUMOURS Contd.
Local extensions from regional
tumours
Craniopharyngiom
a
Paraganglioma
Chordoma
According to location
Intra axial
Extra axial
19. PointsPoints Intra axialIntra axial Extra axialExtra axial
LocationLocation
Within brainWithin brain
parenchyma.parenchyma.
Outside brainOutside 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 bucklingCorticomedullary buckling NoNo YesYes
GM / WM junctionGM / WM junction DestructionDestruction PreservationPreservation
Vascular supplyVascular supply
Internal carotidInternal carotid
arteryartery
External carotidExternal carotid
arteryartery
29. 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 series
2/3rd of all brain tumours are primary neoplasm
Almost ½ of all brain tumours are glioma
¾ th of all gliomas are astrocytic
> ¾ th of all astrocytomas are anaplastic and
GBM
35. Fluorodeoxyglucose usually shows reduced uptake
compared to the rest of the brain, indicative of
hypometabolism
IMAGING STUDY LOW GRADE GLIOMA
PET scan
36. 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
37. 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
38. CT
IMAGING STUDY ANAPLASTIC ASTROCYTOMA
NECT : Iso/hypo In homogenous mixed density
CECT : Enhance strongly, inhomogenously
39. IMAGING STUDY ANAPLASTIC ASTROCYTOMA
MRI
T1: Hypo to iso intense
T2 : Heterogenously Hyperintense
As typically enhance strongly
but non uniformly following
contrast administration.
Irregular rim enhancement is
common
40. Calcification – uncommon
Oedema- perilesional
oedema common
Haemorrhage may occur
Cystic area may present
Mass effect Common
Histologically malignant
OTHER FEATURES
IMAGING STUDY ANAPLASTIC ASTROCYTOMA
41. 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
42. 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
43. 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
44. 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
45. 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 GBM
Angiograph
y
A large mass with striking tumours blush, Contrast stasis
and pooling in Bizarre vascular channel is typical
47. IMAGING STUDY Contd.
Spread
Through white mater
Sub ependymal seedling
Through CSF
Rarely through haemtogenous route
Extra cerebral metastasis- Lung, Liver, Bone
48. PILOCYTIC ASTROCYTOMA
This tumour is of grade –I of WHO grading
Age -most commonly affects the patients in the 2nd decadeof
life
Site - 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
fiber
Eosinophilic granular body common
Microcystic area alternate with pilocytic area
Pathology
49. IMAGING STUDY
CT
Slightly hypodese to isodense
Well-definend core in >50%
Cystic component
Mural nodule with contrast enhancement
Calcification seen in 22% cases
Very little or no oedema
Mass effect present –displaces or compresse 4th ventricle
50. MRI
Sharply defined macrocystic mass
Mural nodule easily
identifiablePronounced contrast enhancement
PILOCYTIC ASTROCYTOMA IMAGING STUDY
51. 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 gliomas
Age distribution- 4th to 5th decade
Peak age - 35-45 yrs.
Location - 85% supratentorial
Cerebral hemisphere- mostly fron
53. 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
54. MRI
Heterogenous signal intensity due to
calcification
T1- weighted image shows mixed hypo or iso intensity
lesion
T2- weighted image shows hyper intense foci
Absent to slight enhancement is typical
T-1 T-1 C T-
2
IMAGING STUDY-
OLIGODENDROGLIOMA
55. IMAGING STUDY-
OLIGODENDROGLIOMA
Other features
Calcification- occurs in 70-90%, peripherally located, clumped
nodules
Cysts are common
Oedema relatively rare
Peritumoural oedema and contrast enhancement is more
common in anaplastic astrocytoma
Histological feature shows ‘fried egg’ appearance
56. 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 tumour
Location- 60% infratentorial more common in children.
40% supratentorial more common in adult.
4th ventricle, C-P angle, in or near 3rd ventricle
57. IMAGING STUDY- EPENDYMOMA
CT
NECT- Mixed density, isodense or slightly hyperdense
Fine calcification seen in approximately 50% of the
patients.
May have cystic areas
CECT- More than 80% contrast enhancement occurs
58. 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
59. IMAGING STUDY- EPENDYMOMA
Other features:Other features:
Hydrocephalus if in posterior fossa.Hydrocephalus if in posterior fossa.
Fine calcificationFine calcification
Headache, nausea, vomiting, papilledema are mostHeadache, nausea, vomiting, papilledema are most
common presentationcommon presentation
60. 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 children
LocationLocation in case of childrenin case of children majority of themajority of the
choroidchoroid
plexus tumour occurs inplexus tumour occurs in laterallateral
ventricleventricle
In adultIn adult most of the choroid plexusmost of the choroid plexus
papilloma occurs inpapilloma occurs in 4th ventricle4th ventricle
61. IMAGING STUDY CHOROID PLEXUSIMAGING STUDY CHOROID PLEXUS
PAPILLOMAPAPILLOMA
CTCT
NECTNECT Iso or hyperdense, 3/4th hyperdenseIso or hyperdense, 3/4th hyperdense
CECTCECT heterogenous contrast enhancementheterogenous contrast enhancement
62. MRIMRI
T1T1 weightedweighted image shows- Predominently isointenseimage shows- Predominently isointense
Intensely contrast enhancementIntensely contrast enhancement
occursoccurs
T2T2 weighted image shows- Iso to hyperintense,weighted image shows- Iso to hyperintense,
occasionally signal void from the vascular pedicleoccasionally signal void from the vascular pedicle
IMAGING STUDY CHOROID PLEXUSIMAGING STUDY CHOROID PLEXUS
PAPILLOMAPAPILLOMA
63. Other features
Calcification occurs in 25% cases
Hydrocephalus severe
Drop metastasis common
The imaging differential diagnosis of choroid plexus
papilloma
In a child CPCs
papillary
ependymomamedulloblastoma
astrocytoma
In adult patient meningioma
metastasis
IMAGING STUDY CHOROID PLEXUS PAPILLOMAIMAGING STUDY CHOROID PLEXUS PAPILLOMA
64. rostrally by the posterior part of 3rd ventricle and
PINEAL TUMOUR
The pineal region is defined as the area of the brain bordered
dorsally by the splenium of corpus callosum and the tela
choroidea
ventrally by the quadrigeminal plate and midbrain tectum
caudally by the cerebellar vermis
65. 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
Germinoma
Teratoma
Embryonal carcinoma
Choriocarcinoma
Pinealoblastoma
Pinealocytoma
Types of pineal region tumour are as follows
66. PINEAL TUMOUR , Cont
Tumour of supporting cells and adjacent structure
Metastic tumour in the pineal
region
Astrocytoma
Meningioma
Benign pineal cyst
Haemangioma
Craniopharyngioma
67. GERMINOMA
This type of germ cell tumour is most common in the pineal region
Incidence 65-72% of all intracranial germ cell tumour
Age distribution 10-30yrs
Consistency is mainly solid, cystic may be present
Radiological study
CT: NECT- slightly hyperdense
Engulfment or displacement of pineal gland is found
CECT- Enhancement occurs strongly and uniformly
68. MRI
Other features
Noncapsulated.
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
69. 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
70. PINEO BLASTOMA
This tumour ( PNET) is highly malignant
Age distribution -1st and 2nd decade
Haemorrhage, calcification, necrosis are common in this type
of tumour. Pineoblastoma disseminate through CSF
Histologically similar to medulloblastoma and retinoblastoma
Imaging study
CT hyper dense lesion
contrast enhancement occurs densely
MRI
T 1 weighted image shows hypointense
T 2 weighted image shows mixed intensity
71. 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
Pituitary adenoma
72. 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 macroadenoma
Pituitary 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
73. FUNCTIONING PITUITARY TUMOUR
Prolactinoma
Somatotrophic tumour(GH secreting)
Corticotrophic tumour( ACTH secreting)
Mixed
Others
Radiological features
Area of haemorrhage, necrosis, cyst formation are less common
RI is the most sensitive imaging study for pituitary tumour
T 1 weighted image (non contrast) shows
hypointense to pituitary gland
gland becomes asymmetric
gland becomes covex
superiorlystalk deviation occurs
depression of sellar floor
74. RADIOLOGICAL FEATURES
After contrast (GD- DTPA) dynamic image is requiredAfter contrast (GD- DTPA) dynamic image is required
Rapid sequence coronal single slice of T 1 weighted imageRapid sequence coronal single slice of T 1 weighted image
of sella immediately after I.V. bolus administration ofof sella immediately after I.V. bolus administration of
contrast with image obtained consecutively of 10 secondcontrast with image obtained consecutively of 10 second
interval upto 3 minutes.interval upto 3 minutes.
Hypo intense tumour over 1st 1-2 minute after injectionHypo intense tumour over 1st 1-2 minute after injection
On delayed film may mask the presence of tumourOn delayed film may mask the presence of tumour
T2 weighted image shows focal mild hyper intensityT2 weighted image shows focal mild hyper intensity
75. PITUITARY MACROADENOMAPITUITARY MACROADENOMA
This type of tumour is usually endocrinologically inactiveThis type of tumour is usually endocrinologically inactive
Incidence- 70-80% ie twice as common as microadenomaIncidence- 70-80% ie twice as common as microadenoma
Age distribution of pituitary macroadenoma- 4th to 5th decade of lifeAge distribution of pituitary macroadenoma- 4th to 5th decade of life
Pituitary macroadenoma becomes symtomatic because ofPituitary macroadenoma becomes symtomatic because of
their mass effect- hypo pituitarism, visual problems etctheir mass effect- hypo pituitarism, visual problems etc
Macroadenoma secrets hormone sub unit, so clinically inactiveMacroadenoma secrets hormone sub unit, so clinically inactive
76. IMAGING STUDY
X-ray
expansion of sellar cavity
thining of bony cortex
ballooning of sella
CT
Large, homogenously isodense, rounded midline mass
77. Extensio
nInto the suprasellar cystern forming the figure of eight(8 )
Elevate and compress the optic chiasma and 3rd ventricle
Laterally into the cavernous sinus
May encase the ICA or narrow the vessels
Area of haemorrhage, necrosis, cyst formation are common
which appear as hypodense within the tumour
Acute or subacute haemorrhage causes focal intratumoural
hyperdense area
Hydrocephalus due to obstruction of foramen monro may
occur
Calcification is rare
PITUITARY MACROADENOMA,PITUITARY MACROADENOMA,
ContCont
78. 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
79. MENINGEAL AND MESENCHYMAL TUMOUR
Meningiomas
Malignant mesenchymal tumour
Hemangiopericytoma
Hemangioblastoma
Meningiomas are most common nonglial primary brain tumour
Most common extra axial tumour (13-18%)
Age – adult tumour 40-60yrs
Sex- more in female
Cytogenetics-chromosome 22 is important for pathogenesis
of meningioma
Meningiomas
80. Neurofibroma type –II is the major predisposing
factor for meningioma
MENINGIOMAS
Origin; Meningioma arises from arachnoid cap cells
In children - > 10% becomes multiple
WHO classification
Typical 88-95%
Atypical 5-7%
Anaplastic 1-2%
Types
globular, flat, compact rounded with invagination of
brainMeningioma enplaque
Multi centric /multifocal
83. IMAGE STUDYIMAGE STUDY
CTCT
70% to 75% hyperdense70% to 75% hyperdense
20% to 25% calcified20% to 25% calcified
90% enhance strongly , uniformly90% enhance strongly , uniformly
10% to 15% cystic areas10% to 15% cystic areas
60% peritumoral edema60% peritumoral edema
HemorrhageHemorrhage
rarerare
Area of haemorrhage, necrosis, cyst formation are commonArea of haemorrhage, necrosis, cyst formation are common
which appear as hypodense within the tumourwhich appear as hypodense within the tumour
84. IMAGE STUDYIMAGE STUDY
AngiographyAngiography
Dual vascular supply commonDual vascular supply common
Sunburst of enlarged dural feeders in tumourSunburst of enlarged dural feeders in tumour
ExtensionExtension
Into 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 sinus
May encase the ICA or narrow the vesselsMay encase the ICA or narrow the vessels
85. Area of haemorrhage, necrosis, cyst formation are common
which appear as hypodense within the tumour
Acute or subacute haemorrhage causes focal intratumoural
hyperdense area
Hydrocephalus due to obstruction of foramen monro may occur.
Calcification is rare
MRI
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
86. 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 massPresent with features of extra axial mass
Neurofibroma:Neurofibroma:
Schwann cell and fibroblast origin,Schwann cell and fibroblast origin,
Noncapsulated,Noncapsulated,
Infiltrating, fusiformInfiltrating, fusiform ,,
IMAGE STUDYIMAGE STUDY
87. - Schwannoma
- Neurofibroma
- Malignant nerve sheath tumour
Nerve Sheath Tumour
Schwannom
a
Benign tumour of schwann cell origin related to cranial nerves.
-90% are solitary
-Multiple Schwannoma are associated with neurofibromatosis type
2
90% of intracranial schwannomas are located in the cerebello
pontine angle originating from VIII cranial nerve- acoustic
neuroma.
88. All the cranial nerves except olfactory and optic nerve, are
partially composed of schwann cells so are potentially site for
schwannoma
Most 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 size
Vestibulo-cochlear nerve- Tinnitus, sensory neural hearing
impairment
Trigeminal nerve- Facial sensory impairment, ataxia, exoph
thalmos, diplopia, corneal reflex loss
89. 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
CT
NECT - 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
90. RADIOLOGICAL STUDY
T 2 weighted image – mild to markedly increased signal intensity.
After contrast- intense enhancement
Homogenous- 62% small
Heterogenous- 22% large
Extension of cerebello pontine angle tumopur into IAC causes
‘cone ice cream’ appearance
91. 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
93. CEREBELLOPONTINE ANGLE (CPA) CISTERN MASSES
Normal Anatomy
The 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
94. CEREBELLOPONTINE ANGLE (CPA) CISTERN MASSES
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.
95.
96. Common CPA
masses
- Vestubular schwannoma (acoustic neuroma)
- Meningioma
- Epidermoid
- Other schwannoma
Less common
- Arachnoid cyst
- Metastases
- Vascular
- Lipoma
- Dermoid.
CEREBELLOPONTINE ANGLE (CPA) CISTERN MASSES
97. 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
CEREBELLOPONTINE ANGLE (CPA) CISTERN MASSES
98. 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
- Astrocytoma
Extrinsic mass- pituitary adenoma, aneurysm, germinoma
102. 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.
103. 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
104. 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
105. 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
106. 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
107. MEDULLOBLASTOMA
Radiological study
CT scan of brain:
Rounded or ovoid, mainly homogenous iso to slightly hyper dense mas
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.
108. 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 intrasellar
Imaging study
CT scan of brain-
90% partially cystic,
90% calcification present,
90% nodular or rim enhancement occur
MRI of Brain
Variable signal, most common is hypointense in T 1 weighted
image and hyperintense in T2 weighted image
109. 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).
110. INTRACRANIAL METASTASES
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
111. Cystic metastasis
INTRACRANIAL METASTASES
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
112. MRI
INTRACRANIAL METASTASES
T 2 weighted image - Most are hyper intense with iso intense rim
Some 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.
