It is basic presentation for MD residents it is very simple presentation for beginners in MD radiology

1. How to approach a case of
suspected brain tumour in
radiology department
DR REKHA KHARE
MD RADIOLOGY

2. What is brain tumor?
• Brain tumors are a diverse group of neoplasms
arising from different cells within the central
nervous system (CNS)
• or from systemic cancers that have metastasized
to the CNS

3. Signs and symptoms
• symptoms and signs are due to
--- local brain invasion
---compression of adjacent structures
--- increased intracranial pressure (ICP)
In addition to the histology of the tumor, the clinical manifestations
could be due to the loss of function of the involved areas of the
brain

4. Patients may present with
• Headache
• Vomiting
• Seizures
• Cognitive disorder
• Focal neurological deficit
• Increased intracranial tension

5. Check for the following:
1. Age of the patient
2. Localization- intra axial or extra-axial or
3. CT or MR tissue characteristics :
Calcifications, fat, cystic component
Signal intensity on T1WI, T2WI and DW
4. Effect on surrounding tissue: mass effect/ oedma
or mid line crossing
5.Single or multifocal
6.Blood brain barrier/ contrast enhancement
7. Pseudo tumour ? an abscess, MS-plaque, vascular
malformation, aneurysm or an infarct with luxury
perfusion
• Age of the patient
• Is it extra or intra
axial
• CT or MRI
characteristic
• Mass effect/
midline crossing
• Single or multiple
• Contrast
enhancement
• Is it pseudo tumour

6. Age--Brain tumour in paediatrics
Under the age of 2 : choroid plexus papillomas,
anaplastic astrocytomas and
teratomas.
In the first decade: medulloblastomas, astrocytomas,
ependymomas,
craniopharyngeomas
, gliomas
metastases of a neuroblastoma are the most
frequent in this age grp

7. Brain tumour in adults
• About 50% of all CNS lesions are metastasis
• Other common tumors in adults are
astrocytomas, glioblastoma multiforme,
meningiomas, oligodendrogliomas, pituitary
adenomas and schwannomas.
Astrocytomas occur at any age, but
glioblastoma multiforme is mostly seen
in older people.

8. CNS Tumour--
incidence
Roughly
-- one-third of CNS
tumors are
metastatic lesions, -
--one third are
gliomas
---one-third is of
non-glial origin.

9. CNS Tumour
• Glioma is a non-specific term indicating that the tumor
originates from glial cells like astrocytes,
oligodendrocytes, ependymal and choroid plexus cells
•
Astrocytoma is the most common glioma and can be
subdivided into the low-grade pilocytic type, the
intermediate anaplastic type and the high grade
malignant glioblastoma multiforme (GBM).
•
GBM is the most common type (50% of all
astrocytomas).
The non-glial cell tumors are a large heterogenous group
of tumors of which meningioma is the most common.

10. Intra axial versus extra axial

11. Intra vs Extra axial • Difference in Intra axial
vs Extra axial usually
straight forward
• if difficult check for gray
matter, which goes
pushed away in extra
axial

12. Extra axial- mass is outside the
brain derived from lining of brain or surrounding
structure

13. Extra axial brain tumour
Common:
Meningioma
Schwannoma.

14. Axial CT With & without contrast
SPOKE WHEEL PATTERN with in vividly enhancing
meningioma

15. Meningioma on MRI
• Meningioma appear as dura
based masses isointense to
grey matter on both T1 and T2
weighted imaging, and
demonstrate vivid contras

16. Cerebellopontine mass
On the left a 52-year-
old male with hearing
loss on the right
The images show an
unusual cystic mass
with enhancing
septations.
There is also some
enhancement within
the internal acoustic
canal.

17. CP mass---patient with hearing loss

18. schwannoma meningioma
Coronal enhanced T1WI. Meningioma with
dural tail, hyperostosis of adjacent bone and
homogeneous enhancement
Schwannoma in CPA-region with typical
features of an extraaxial tumor (T2WI)

19. Common brain tumour in childhood

20. PNET and DNET
histopathological diagnosis
• PNET (primitive
neuroectodermal tumor)
is a name used for tumors
which appear identical under
the microscope to
medulloblastoma,
but occur primarily in the
cerebrum.
• Dysembryoplastic
neuroepithelial tumour (DNT
, DNET) is a type of brain
tumor.
• Most commonly found in the
temporal lobe
• DNTs have been classified as
benign tumours
• These are glioneuronal
tumours comprising both glial
and neuron cells and often
have ties to focal cortical
dysplasia.

21. Common brain tumours in adults
Metastasis are the most common

22. Effect on surrounding tissue
• Primary brain tumors are derived from brain
cells and often have less mass effect for their size
than you would expect, due to their infiltrative
growth.
•
This is not the case with metastases and extra-
axial tumors like meningiomas or schwannomas,
which have more mass effect due to their
expansive growth.

23. Local tumor spread---
actual size of tumour is greater than expected
• Astrocytoma---infiltrative mass ,do not respect
boundary of lobe, may spread to adjoining white
matter
• Ependymoma---may spread to 4th ventricle to
cisterna magna or to CP angle
• Oligodendroglioma---may extend to cortex

24. EPENDYMOMA---
extenesion
Ependymoma of the
fourth ventricle in children
tend to extend through the
foramen of Magendie to the
cisterna magna and through
the lateral foramina of
Luschka to the
cerebellopontine angle

25. Meduloblastoma
The most common malignant brain tumour of childhood. They most
commonly present as midline masses in the roof of the 4th ventricle with
mass effect and hydrocephalus

26. common sella and parasellar mass

27. Craniopharyngioma/
macroadenoma
NECT and enhanced
CT-images of a 33-
year-old female with
severe headache (worse
in the a.m.), reduction
in visual acuity and
visual fields and
papilledema

28. Case --- patient with progressive
visual loss.
On the coronal and sagittal TW1I
there is a large mass centered
around the sella with a broad
dural base.
There is extension into the sella.
It would be impossible to operate
this tumor and preserve the
patient's vision so decompression
is needed

29. Pineal region mass

30. Imaging pineal mass
• On CT usually large lobulated and enhancing tumors
(more than 3 cm), hyperattenuating (highly cellular),
with heterogeneous signal intensities
• on MRI, sometimes with evident necrotic and
hemorrhage regions.
• Restricted diffusion is commonly evident and, in almost
all cases, obstructive hydrocephalus is observed at the
presentation

31. Pinealoblastoma on DWI
They are the most aggressive and highest grade tumour among pineal
parenchymal tumours: Heterogenously enhancing pineal mass
Case---A 12 y/o male with upward gaze paralysis.

32. Midline crossing
• The ability of tumors to cross the midline limits the differential
diagnosis.
• Glioblastoma multiforme (GBM) frequently crosses the
midline by infiltrating the white matter tracts of the corpus
callosum.
• Radiation necrosis can look like recurrent GBM and can
sometimes cross the midline.
• Meningioma is an extra-axial tumor and can spread along the
meninges to the contralateral side.
• Lymphoma is usually located near the midline.
• Epidermoid cysts can cross the midline via the subarachnoid
space.
• MS can also present as a mass lesion in the corpus callosum.

33. Midline crossing

34. Single or multiple
• Multiple tumors in the brain usually indicate metastatic
disease
•
Primary brain tumors are typically seen in a single
region, but some brain tumors like lymphomas,
multicentric glioblastomas and gliomatosis cerebri can
be multifocal
• Meningioma schwannoma could be multifocal
• Neurofibromatosis, Haemangioblastoma could be
multifocal

35. Single vs multifocal
• Many non-tumorous diseases like
• small vessel disease,
• infections (septic emboli, abscesses)
• demyelinating diseases like MS ,
• tuberous sclerosis can also present as multifocal
disease

36. Blood Brain barrier-how the contrast works?
The brain has a unique triple layered blood-brain
barrier (BBB) with tight endothelial junctions in
order to maintain a consistent internal milieu.
Contrast will not leak into the brain unless this
barrier is damaged.
Enhancement is seen when a CNS tumor destroys
the BBB.
• Extra-axial tumors such as meningiomas and
schwannomas are not derived from brain cells and
do not have a blood-brain barrier so markedly
enhancement

37. Homogeneous enhancement
• Metastases
• Lymphoma
• Germinoma and other pineal gland tumors
• Pituitary macroadenoma
• Pilocytic astrocytoma and hemangioblastoma
(only the solid component)
• Ganglioglioma
• Meningioma and Schwannoma

38. No enhancement can be seen in:
• Low grade astrocytomas
• Cystic non-tumoral lesions:
▫ Dermoid cyst
▫ Epidermoid cyst
▫ Arachnoid cyst

39. Contrast enhancement in non
tumorous lesion
• These can also break down the BBB
and may simulate a brain tumor.
•
These lesions include like infections,
demyelinating diseases (MS) and infarctions.

40. Patchy enhancement can be seen
in:
• Metastases
• Oligodendroglioma
• Glioblastoma multiforme
• Radiation necrosis

41. Ring enhancement

42. Tumour mimics or pseudotumour
• Many non-tumorous lesions can mimic a brain
tumor.
Abscesses can mimic metastases.
Multiple sclerosis can present with a mass-like
lesion with enhancement, also known as
tumefactive multiple sclerosis..
In the parasellar region one should always
consider the possibility of a aneurysm.

43. Cystic lesion simulate
CNS tumour
epidermoid, dermoid,
arachnoid, neuroenteric and
neuroglial cysts.
Even enlarged perivascular
spaces of Virchow Robin
can simulate a tumor.
characteristics: of
cystic lesion
•Morphology
•Fluid/fluid level
•Content usually isointense
to CSF on T1, T2 and FLAIR
•DWI: restricted diffusion

44. MRI characteristics ----High signal on T1
Fat is low -100 on CT
scan but
on MRI it is high
signal
High signal on MRI ---
Hemorrhagic mass

45. MRI characteristics
Low signal on T2
Most tumors are bright on T2WI due
to a high water content.
When tumors have a low water
content they are very dense and
hypercellular and the cells have a high
nuclear-cytoplasmasmic ratio.
These tumors will be dark on T2WI.
The classic examples are CNS
lymphoma and PNET (also
hyperdense on CT).
Calcifications are mostly dark on
T2WI.
Paramagnetic effects cause a signal
drop and are seen in tumors that
contain hemosiderin.
Proteinaceous material can be dark on
T2 depending on the content of the
protein itself

46. DWI -- Diffusion weighted imaging
• Normal water protons have the ability to diffuse
extracelluarily and loose signal
• High signal on DWI indicates restriction ability of water
proton to diffuse extracelluarily
• Restricted diffusion in abscess due to viscosity of pus so
high signal

47. Perfusion imaging MRI
• It plays an important role for grading of mass
• Perfusion depends on vascularity of mass not dependant
on blood brain barrier
• Amount of perfusion correlates better with grading of
malignancy than the amount of contrast enhancement

48. Tumor with calcification
calcification on CT or MRIThe calcification is not
appreciated on the MR
images, but is easily
seen on CT
The calcification and the
extension of the tumor
to the cortex are very
typical for an
oligodendroglioma
D/D astrocytoma

49. Calcification in mass
• When we think of a calcified
intra-axial tumor, we think
oligodendroglioma since these
tumors nearly always have
calcifications.
•
However an intraaxial calcified
tumor in the brain is more
likely to be an astrocytoma
than a oligodendrogliomas,
since astrocytomas, although
less frequently calcified, are
far more common.
A pineocytoma itself does not
calcify, but instead it 'explodes'
the calcifications of the pineal
gland.
• a calcified mass in the
suprasellar region, causing
obstructive hydrocephalus.
•
This location in the suprasellar
region and the calcification are
typical for a
craniopharyngioma.
are slow growing, extra-axial,
squamous epithelial, calcified,
cystic tumors arising from
remnants of Rathke's cleft.
•
They are located the
(supra)sellar region and
primarily seen in children with
a small second peak incidence
in older adults.

50. Mass with
calcification
• A 52-year-old female who,
over the period of one year,
complained of headache and
neck pain.
There is a recent onset of
tonic-clonic seizures
•
The CT shows a mass with
calcifications, which extends
all the way to the cortex,
limited mass effect on
surrounding structures, which
indicates that this is an
infiltrating tumor
• The most likely diagnosis is
oligodendroglioma.
The differential diagnosis
includes a malignant
astrocytoma or a glioblastoma

51. Cortical based tumour—
presenting as seizure
• A 45-year-old female with a stable seizure disorder
(complex-partial) for 15 years
•
There is a non-enhancing, cortically based tumor.
This is a ganglioglioma.
The differential diagnosis includes DNET and
pilocytic astrocytoma.
• These cortically based tumors have to be
differentiated from non-tumorous lesions like
cerebritis, herpes simplex encephalitis, infarction
and post-ictal changes

52. Skull base tumour

53. Have a pleasant day