9. Glioma(Low grade astrocytoma)Glioma(Low grade astrocytoma)
Pathology
Either focal well delineated or diffusely
infiltrating mass.WHO grade II
Incidence-10-15 % of astrocytoma
Age-Children & young adult between 20-40 yrs
Location-Cerebral haemispheres.
Natural history-7-10 yrs survival.
Death due to degeneration into higher grade
neoplasm
12. Glioblastoma multiforme(GBMGlioblastoma multiforme(GBM))
Pathology
Most malignant of all glial neoplasm.
Poorly delineated partially necrotic mass
WHO grade –IV
Incidence-50 % of all glial neoplasm
Age- Older patient >50 yrs; rare <30 yrs.
Location- Deep cerebral white matter
Natural history-Spread rapidly & diffusely
Postoperative survival of GBM is 08 month
05 yrs recurrence free survival rate is essentially zero.
13. ImagingImaging
NECT-Heterogeneous mixed density mass having necrosis or
cystic changes
Marked perifocal oedema
Haemorrhage common.Calcification rare
CECT- Strongly enhance but very inhomogeneous.Thick
irregular rim enhanement is common.
MR-T1-Mixed signal mass with necrosis or cyst
formation and a thick irregular wall.
Marked heterogeneous enhancement is noted.
T2-Heterogenously hyperintense with perifocal oedema.
19. Pituitary AdenomaPituitary Adenoma
Pathology
Macroadenoma > 10 mm ,Microadenoma <10 mm
Necrosis,cyst formation & haemorrhagic foci common
Incidence
10% of all primary tumor
Microadenoma>>Macroadenoma
Imaged based-Macroadenoma twice as microadenoma
Age & Gender
Adult tumor(<10% in children)
F:M=4-5:1 for prolactinoma; M:F=2:1 for growth
hormone cell adenoma
20. ImagingImaging
Plain X-Ray
Sella is expanded,widened and eroded
CT
Microadenoma-Isodense/isointense on NECT/MR
Hypodense/hypointense on dynamic CECT-appears filling
defect within enhanced normal gland.
Macroadenoma-
NECT- Most are isodence with the cortex
Calcification rare-1-4%
Necrosis,cyst formation and haemorrhage causes
mixed density lesion
CECT - Moderate enhancement .
MR- Signal like cotrex on T1 & T2.
Variable if haemorrhage,necrosis or cyst formation is present.
26. CraniopharyngiomaCraniopharyngioma
Etiology
Arises from squamous rest along Rathke’s cleft
Pathology
Gross- Well delineated cyst with mural nodule most common
Micro-Squamous epthelium with necrosis,debris,cholesterol
clefts,keratin pearls.
Incidence
3-5% of all primary brain tumor
50% of paed.suprasellar tumors.
Age
Peak age-8-12 years
Second peak-40-60 years
Location
70% combined suprasellar/intrasellar,Intrasellar is rare.
27. ImagingImaging
NECTC- * Cystic appearing lobulated suprasellar mass with
* mural nodule
* Nodular or rim calcification-in 80% paed.case,50%-adult
* Density of cyst is slightly higher than CSF.
CECT- Nodular or rim enhancement in more than 90% cases.
MR - * Hypointense on TI & Hyperintense on T2
* Hyperintense on T1 if high protein concentration
* Nodular or rim enhancement after contrast.
30. Acoustic SchwannomaAcoustic Schwannoma
Pathology
Arises from schwann cells
Encapsulated,Focal & Round
Cyst,necrosis & haemorrhage common
Don’t undergo malignant transformation.
Multiple –NF 2
Incidence - 6-8% of primary brain tumor
Age - 40-60 yrs common
Location-CN VIII - CP angle
31. ImagingImaging
Plain X-Ray-Widening of the internal auditory canal
NECT
Isodense or slightly hyperdense to adjacent brain
Mixed density if cystic change or necrosis is present.
CECT
Virtually all schwannoma enhancee strongly following
contrast.
Heterogeneous enhancement occurs if cystic change or
necrosis is present.
MR-
T1-2/3rd
hypointense,1/3rd
isointense
T2-Hyperintense
Strongly enhance after contrast.
35. MedulloblastomaMedulloblastoma
Pathology
75% in the vermis,25% in the lateral cerebellum
Uncapsulated but relatively well circumscribed spherical midline
posterior cranial fossa mass
Anteriorly bulges into 4th
ventricle & posteriorly into cisterna magna
Densely cellular
Gross calcification,cyst formation and haemorrhage are rare
Incidence-15-25% 0f primary CNS tumor in children.
one third of posterior fossa tumor in children common.
75% in the vermis
Age & Sex-75% <15 yrs of age
50% in the first decade
Second smaller peak age in adult 24-30 yrs
M:F=1.5 to 3:I
36. ImagingImaging
CT
Hyperdense on NECT; Enhance strongly following
contrast
Obstructive hydrocephalus is common
Calcification –15%
MR
Hypointense on T1W1,Variable on T2W2
Moderately intense enhancement is typical
Heterogenous –if cystic changes is present.
42. Arachnoid cystArachnoid cyst
Etiology-Meningeal maldevelopment
Pathology
Thin walled CSF like fluid filled cavity that
lie entirely within the arachnoid membrane
lined by flattened arachnoid cells.
Incidence-1% of all intracranial mass.
Age and sex-Any age but 75% in
children.M:F=3:1
Clinical presentation-headache,seizures and
focal neurological sign.
44. ImagingImaging
CT
Smoothly marginated nonenhancing extra-
axial mass similar to CSF attenuation
Pressure erosion of adjacent calvaria can
occur.
MR
They parallel CSF signal intensity on all
pulse sequence.The cyst has no internal
character unless haemorrhage or high
protein content.
52. AVMAVM
Pathology
AVMs are complex network of abnormal
vascular channels that consists of arterial
feeders,arterial collaterals,the AVM nidus
and enlarged venous out flow channels.
Congenital
Dilated arteries and veins without capillary
bed.
May contains non funtional gliotic brain.
54. ImagingImaging
NECT-Isointense or slightly hyperintense lesion.
Calcification is noted in 25-40%
Haemorrhage may be found.
CECT-Intense serpiginous enhancement is noted in
the vessels.
MR-Tightly packed of honeycomb of flow void.
Areas of increased signal if vessels are
thrombosed or slow and turbulence flow.
Haemorrhage in different stage of evolution.
56. SchizencephalySchizencephaly
Gray matter lined CSF filled clrft that
extended from the ependymal surface of the
brain through white matter to the pia.
Type-I Closed lip-in which the cleft walls are
in apposition
Type-II Open lip-in which the cleft walls are
separated.