mets, medulloblastoma, PCA

1. INTRAAXIAL POSTERIOR FOSSA
TUMORS
DR PRAVEEN K TRIPATHI
02-Mar-16 1

2. Posterior fossa - Outline
 Calvarium
◦ Posterior skull base
 Brainstem anteriorly
◦ Midbrain, pons and medulla
 Cerebellum posteriorly
◦ 2 Hemispheres and midline vermis
 Divided into:
◦ Mesencephalon (midbrain)
◦ Rhomboencephalon (pons, medulla and cerebellum)
 Cerebral aquaduct and fourth ventricle
 CSF cisterns containing vertebrobasilar arteries
and veins 02-Mar-16 2

3. Background
 Posterior fossa tumors are more common in
children than the adults.
 Primary brain tumors are the most common solid
tumors in the pediatric population, comprising 20%
to 25% of all childhood cancers.
 About 60% to 70% of all pediatric brain tumors
originate in the posterior fossa.
 About 15-20% of brain tumors in adults occur in
the posterior fossa.
 Hydrocephalus is common in children with
posterior fossa tumors, occurring in 71% to 90% of
pediatric patients
02-Mar-16 3

4. Brain Tumors - Background
 Primary brain tumor – 6 persons/100000/year
 Metastatic brain tumor – 6 persons/100000/year
 1 in 15 primary brain tumors occur in children under
15 years
 20-30% of cancers in children
 2500-3000 new diagnoses/year
 2nd most common neoplasm
 Most occur before age 10 years
 Male/Female = 1.3/1.0
 60-70% 5 year survival
02-Mar-16 4

5. Aetiology
No specific
Genetic
Environmental
02-Mar-16 5

6. Classification
02-Mar-16 6

7. Extra-axial Lesion
 Vestibular schwannoma
 Meningioma
 Epidermoid
 Metastases
 Trigeminal neuroma
 Facial nerve neuroma
 Arachnoid cyst
02-Mar-16 7

8. Intra-axial Post Fossa Tumors-
adults
Cerebellar
liponeuroc
ytoma
Metastasis
16%
Hemangiobl
astoma 7-
12%
Pilocytic
astrocytoma
(2nd
decade)
Brain stem
glioma (1%
of adult
tumor)
Choroid
plexus
tumor
(<1%)
02-Mar-16 8

9. Intra-axial Post Fossa Tumors-
pediatrics
PNET (including medulloblastoma) 27%
Cerebellar (Pilocytic
astrocytoma) 27%
Brain stem glioma 27%
Ependymoma 15%
Choroid plexus papilloma (<1%)
Dermoid cyst
Atypical teratoid/ rhabdoid tumor02-Mar-16 9

10. Posterior Fossa & Brainstem
Tumors - Clinical Features
Posterior Fossa
primary
Ataxia
Tremors
Dysarthria
Stiff
neck
Papilledema
Extremity
weakness
Cranial nerve
signs
• double vision
• facial weakness
• swallowing
dysfunction
Brainstem
primary
02-Mar-16 10

11. Metastases
 MC post fossa tumor in
adults
 Cerebellum is a common site
 16% of cases of solitary
brain mets
Primary
 Lung – 44%
 Breast – 10%
 Kidney (renal cell) – 7%
 GI – 6%
 Melanoma – 3%
 Undetermined – 10%
02-Mar-16 11

12. Pathology
 Rounded solid partially cystic mass ± edema
Age
 Rare in children, most common in older adults
(> 40 years)
Location
 Anywhere: grey white junction most common site
Imaging
 NECT: Iso / hyperdense; Ca++ rare in untreated
metastases
 CECT: Strong solid/ring enhancement
 MR: Most hypointense on T1, hyperintense on T2W1,
most enhance moderately intensely following contrast
administration
02-Mar-16 12

13. Mets- images
Axial CT contrast image showing
multiple metastases
Axial T2 image showing SINGLE
metastases
02-Mar-16 13

14. Management
The goals of treating brain metastases are
(1) to establish a histologic diagnosis,
(2) to relieve neurologic symptoms,
(3) to provide long-term local disease control.
 Mostly palliative
 Median survival of patient 26-32 weeks
Medical
 Corticosteroids
 Anticonvulsants.
02-Mar-16 14

15. Considerations in Patient Selection
for Surgical Removal of Brain Metastases
02-Mar-16 15

16. Surgical Management
Solitary lesion
Surgical excision of solitary lesion:
 Primary disease quiescent or radioresistant
 Lesion accessible, symptomatic or life threatening
 For recurrent small cell lung carcinoma following
XRT
 Diagnosis unknown
02-Mar-16 16

17. Multiple Lesions
 Worse prognosis than solitary lesion
 Usually treated with XRT without surgery
Situations where surgery is done:
 One particular and accessible lesion
symptomatic and/or life threatening
 Multiple lesions that can all be completely
removed
Stereotactic Biopsy
 Lesions not appropriate for surgery
 Not candidates for surgical resection
 To ascertain a diagnosis
02-Mar-16 17

18. Stereotactic Radiosurgery
 No mass effect, no hydrocephalus
 Advantage: No risk of hemorrhage,
infection or mechanical spread of tumor
cells, Can be used for 3 or fewer mets
 Disadvantage: Histological proof not
obtained, Cannot be used for lesion > 3
cm
02-Mar-16 18

19. Newly diagnosed brain metastasis
management flowchart
02-Mar-16 19

20. Median survival following craniotomy
Month
Lung 11
Breast 11
Colon 8
Kidney 12
Melanoma 6.5
Miscellaneous 11
Sarcoma 6
Urologic (testis, Bladder, Prostate) 10
Unknown 10
Esophagus 4
Median survival even with best treatment is only – 8
months02-Mar-16 20

21. Hemangioblastoma (HGB)
 Most common primary intra-axial posterior fossa tumor in
adults (7-12% of post fossa tumors)
 Highly vascular well circumscribed solid or cystic neoplasm
of CNS or retina
 May occur sporadically (4th Decade) or as part of Von
Hippel Lindau disease (3rd decade)
Associations
 phaeochromocytoma
 multiple RCCs
 von Hippel Lindau (vHL) disease:
◦ ~45% of those with vHL develop haemangioblastomas
◦ ~20% of those with haemangioblastoma have vHL
 polycythaemia: due to secretion of erythropoietin
from lesions
02-Mar-16 21

22.  60% cystic with nodule – 40% solid
 Gross hemorrhage, calcification necrosis rare
 Adults with peak during 40 to 60 years, rare in children
Location
 intracranial: 87-97%
◦ 95% in posterior fossa
 85% in cerebellar hemisphere
 10% in the cerebellar vermis
 5% medulla
 only rarely do they extend beyond the cerebellum into the
cerebellopontine angle
◦ 5% supratentorially (typically in the optic radiations)
◦ cerebral haemangioblastomas are only really seen in
patients with vHL
 spinal: 3-13% 02-Mar-16 22

23. Clinical features of hemangioblastoma
• Headache (75%)
• Gait difficulties (55%)
• Dysmetria (29%)
• Nausea or vomiting (28%)
• Nystagmus (13%)
• Dysarthria (9%) and/or dysphagia (8%)
• Hydrocephalus (28%)
02-Mar-16 23

24. Hemangioblastoma -Imaging
CT
 the mural nodule is isodense to brain on non-contrast scans with fluid density surrounding cyst
 bright enhancement of the nodule is demonstrated with contrast
 the cyst walls do not usually enhance & calcification is not a feature
MRI
 T1
◦ hypointense to isointense mural nodule,
◦ CSF signal cyst content
 T1 C+ (Gd)
◦ mural nodule vividly enhances
◦ cyst wall does not enhance
 T2
◦ hyperintense mural nodule
◦ flow voids due to enlarged vessels may be evident especially at the periphery of the cyst, seen in 60-
70% of cases
◦ fluid filled cyst, similar to CSF
MR perfusion imaging: high rCBV ratios
Angiography (DSA)
 Enlarged feeding arteries and often dilated draining veins are demonstrated, with a dense tumour blush
centrally 02-Mar-16 24

25. Coronal MRI gadolinium image showing
cystic hemangioblastoma with a mural
nodule
CT showing cystic hemangioblastoma
with a mural nodule
Imaging
02-Mar-16 25

26. Hemangioblastoma -Imaging
Sagittal MRI gadolinium image showing a
cerebellar and spinal hemangioblastomas
Computed tomography angio showing
vascularity of left cerebellar
hemangioblastoma02-Mar-16 26

27. Treatment
 Surgical resection is the treatment of choice.
 Generally, resection of hemangioblastomas in
patients with VHL disease is indicated only when
the lesions produce
 Preop embolisation reduces the vascularity
 Cystic hemagloblastoma require removal of mural
nodule.
 Cyst drainage alone is of no benefit.
Stereotactic Radiosurgery
 For asymptomatic HGB > 5 mm diameter if they are
cystic or progressing in size during surveillance
02-Mar-16 27

28. Radiation Treatment
 May be useful to reduce tumor size or to retard
growth in patients who are not surgical candidates
for multiple brainstem HGB
Chemotherapy
 Ongoing phase II trial with Sunitnib, an inhibitor of
vascular endothelial growth factor and platelet
derived growth factor
02-Mar-16 28

29.  Medulloblastoma was first described by Bailey and
Cushing in 1924, using the terminology
‘spongioblastoma cerebelli
 Origin of cells (WHO- PNET)
Static- external granular layer Origin from
remnant of cells of the external granular layer of the
cerebellum.
Dynamic – neural progenitor cells
Transformation of normal undifferentiated
progenitor cells of superior medullary velum
which migrate to the fourth ventricle.
MEDULLOBLASTOMA
02-Mar-16 29

30.  Medulloblastomas are the most common
posterior fossa tumors constituting 6% of all
intracranial neoplasms, 12% of all
neuroectodermal tumors
 most common malignant brain tumor in
children-30% of all pediatric brain tumors.
 The first decade of life accounts for more than
50% of these tumors.
 A third of them occur between the ages of 15
years and 35 years.
 There is a slight male preponderance.
MEDULLOBLASTOMA
02-Mar-16 30

31.  The majority (85%) arise from the cerebellar vermis
and in the minority, they arise laterally from the
cerebellar hemisphere.
 Several cancer predisposition syndromes are
associated with medulloblastoma including
◦ Gorlin’s syndrome,
◦ Turcot’s syndrome,
◦ Li-Fraumeni syndrome, and
◦ Rubenstein-Taybi syndrome
 Common chromosomal copy number changes
include gain of chromosomes 1q and 7, as well as
loss of chromosomes 22, 11, 10q, and 17p.
 Loss of 17p is observed in up to 50% of cases
MEDULLOBLASTOMA
02-Mar-16 31

32. Histology
 Medulloblastoma (Grade 4)
 Medulloblastoma with extensive
nodularity (MOST COMMON)
 Desmoplastic/nodular
medulloblastoma
 Anaplastic medulloblastoma
 Large cell medulloblastoma
MEDULLOBLASTOMA
Cellular, small cells, scant
cytoplasm, Homer-Wright rosettes
Immuno histochemistry
GFAP +
EMA –
02-Mar-16 32

33. CLINICAL FEATURES
Hydrocephalus : raised ICP
 Behavioral change, listlessness, irritability, vomiting, and
decreased social interactions.
 Headache
 Double vision.
 Head tilt : tonsillar herniation below the foramen
magnum
 Cerebellar symptoms
 Brain stem involvement
 Leptomeningeal dissemination
MEDULLOBLASTOMA
02-Mar-16 33

34. Examination
• Increasing head circumference , full anterior
fontanelle with widely split cranial sutures.
• Papilledema 90% of patients
• Diplopia and lateral gaze paresis
• Fourth cranial nerve palsy ( should be considered in
any patient with a head tilt )
• Nystagmus
• Cerebellar signs ( ataxia > unilateral dysmetria )
MEDULLOBLASTOMA
02-Mar-16 34

35. M
E
D
U
L
L
O
B
L
A
S
T
O
M
A
CT
•On CT, medulloblastomas appear as a mass arising from the vermis, resulting
in effacement of the fourth ventricle / basal cisterns and obstructive
hydrocephalus.
•They are usually hyperdense (90%) and cysts formation/necrosis is common
(40-50%), especially in older patients.
•Calcification is seen in 10-20% of cases .
•Enhancement is present in over 90% of cases and is usually prominent
MRI
T1
hypointense to grey matter
T1 C+ (Gd)
overall 90% enhance, often heterogeneously
T2/FLAIR
overall are iso to hyperintense to grey matter
heterogeneous due to calcification, necrosis and cyst formation
surrounding oedema is common
DWI/ADC- restricted diffusion (low ADC values)
MR spectroscopy
elevated choline
decreased NAA
may show a taurine peak 02-Mar-16 35

36. Medulloblastoma
(A) Contrast CT, (B) MRI T1, (C) MRI gadolinium images showing medulloblastoma
02-Mar-16 36

37. Spinal imaging –
◦ At diagnosis (11-71% show dissemination)
◦ Within 24 hrs after surgery or 2 weeks post
surgery
◦ Surveillance imaging at 3-6 months
MEDULLOBLASTOMA
02-Mar-16 37

38. CHANG CLASSIFICATION
MEDULLOBLASTOMA
Stage Feature
Tumor stage
T1 Less than 3 cm diameter, limited to vermis, roof of fourth ventricle, or hemisphere
T2 More than 3 cm diameter, invades one adjacent structure or partially fills fourth
ventricle.
T3a Invades two adjacent structure or completely fills fourth ventricle with extension into
cerebral aqueduct, foramen of Luschka, or formen of Magndie.
T3b Arises from floor of fourth ventricle or brain stem; fourth ventricle completely filled
T4 Spreads to involve cerebral aqueduct, third ventrical, midbrain, or upper cervical spinal
cord
Metastasis stage
M0 No evidence of metastasis
M1 Tumor cells in CSF
M2 Gross nodular seeding of brain CSF spaces
M3 Gross nodular seeding of spinal CSF spaces
M4 Extraneural spread
02-Mar-16 38

39. Current staging of medulloblastoma
STANDARD RISK
 No residual tumor on
postop MRI and negative
CSF result
 5 years survival is >5%
and progression free
survival = 50%
HIGH RISK
 Bulky residual tumor > 1.5
cm2 postop
 Dissemination in the brain,
spine or CSF
 Worse prognosis
 5 year disease free survival
is 35-50%
02-Mar-16 39

40.  Management
Steroids
CSF cytology- LP, EVD, Cisternamagna
CSF diversion
Definitive surgery
Adjuvant therapy
MEDULLOBLASTOMA
02-Mar-16 40

41. Management algorithm for medulloblastoma
Presenation : MRI Brain and spine
Surgical resection
Management of hydrocephalus
> 3 years < 3 years
Standard risk Poor risk
Craniospinal radiation
OR Reduced dose radiation with
CT on reasarch protocol
Cranispinal radiation + adjunct CT
( CCNU, cisplatin vincristine
or CT on research protocol
Chemotherapy (No standard regimen)
Follow OR
Delayed RT till 3 years old
02-Mar-16 41

42. Management…….. Surgery
 Gross Total Resection, if possible (arises from roof of
fourth ventricle- soft reddish vascular with some times
sugar coating).
 Brainstem damage should be avoided.
 Resolution of natural CSF pathways.
 SURGERY alone : NOT CURATIVE
 RADIOTHERAPY : Cornerstone of adjuvant therapy.
 54 to 58 Gy - primary site
 35Gy - craniospinal axis
02-Mar-16 42

43. Medulloblastoma
Prognostic Factors
 Age - Younger tend to do worse
 Extent of resection
 Non-posterior fossa tumors
 Non-localized disease
 Standard risk 70-80% 5 yr survival
High risk 50%
what are risk groups?
02-Mar-16 43

44. Management…….. Recurrent
Medulloblastoma
 Chemotherapy : limited due to chemo resistance in
those patients who have previously undergone CT
 Redosing with RT avoided due to radiation necrosis
 High-dose chemotherapy with autologous SCR or
autologous BMR: subject of intense investigation
Prognosis
 After craniospinal radiotherapy, children, especially
those younger than 7 years, will have significant
intellectual compromise
 5 - year recurrence-free survival rates : 55% - 67%.
• Most common site : PRIMARY TUMOR SITE
02-Mar-16 44

45. Ependymoma
 Predominantly intraventricular and account
for 1–3% of all primary brain tumors.
 In children, they constitute 9% of intracranial
tumors and are third in frequency after
astrocytoma and medulloblastoma
 Peak age - 0-4yrs
 Male preponderance
 Children 90% in cranium
 Adults in spinal
02-Mar-16 45

46. EPENDYMOMA
 MYXOPAPILLARY (WHO Grade 1)
 SUBEPENDYMOMA (WHO Grade 1)
 Ependymoma (WHO Grade 2)
 Cellular
 Papillary
 Clear cell
 Tanycytic
 Anaplastic ependymoma (WHO Grade 3)
02-Mar-16 46

47. Ependymoma …….. Imaging
CT Brain
 coarse calcification is
common (50%)
 cystic areas (50%)
 solid component iso to
hypodense
 heterogeneous
enhancement
 a small proportion can
have haemorrhage
02-Mar-16 47

48. Ependymoma…..MRI
On MRI, heterogeneous secondary to necrosis,
hemorrhage and calcification.
Heterogenous contrast enhancement
Plasticity
Extension to the cerebellopontine angle is
characteristic of ependymomas
02-Mar-16 48

49. MRI gadolinium (A) sagittal, (B) axial images showing fourth ventricular
ependymoma
02-Mar-16 49

50. Ependymoma
02-Mar-16 50

51. TREATMENT
 Surgical excision and postoperative
irrradiation have been the mainstay of
treatment.
 Radiation therapy is usually administered to
children more than 3 years of age after
recovery from surgery
 Surgery and radiation therapy yield 5-year
progression-free survival ranging from 60%
to 87% after complete resection
 The incidence of dissemination of
ependymoma is only 11% to 17%.
02-Mar-16 51

52. Ependymoma…..
 INTRA OP- Tumor arises from the floor and is
greyish lobulated gritty and firm
 Staging: No conventional staging criteria.
 Postoperative MRI is recommended within 48 hours
02-Mar-16 52

53. Ependymoma…Role of Radiotherapy
 Post-operative radiation recommended for patients older
than 3 years.
 The dose of radiation for the treatment of ependymoma
has traditionally been in the range of 4500 to 5600 cGy.
 Stereotactic radiosurgery : Therapeutic option in patients
with residual, unresectable or recurrent tumor
Role of Chemotherapy
 May be useful < 3 years : Delay cranial radiation
 Childhood intracranial ependymomas : in general chemo-
resistant
02-Mar-16 53

54. AIIMS Protocol
•
Low Grade
CSF -VE
Surgery Surgery
Radiotherapy
56Gy / 28# / 5.5 wks
(50 Gy followed by a boost of 6 Gy)
Surgery followed by
CSI and 6 cycles
chemotherapy.
High grade
CSF + VE
02-Mar-16 54

55. Cerebellar (Pilocytic astrocytoma)
 10-20% of pediatric brain tumour
 Pilocytic astrocytoma is the most common
pediatric central nervous system glial neoplasm
 A mean age at presentation of 6 to 8 years is found
 Rarely found in children under 1 year of age or in
adults over the age of 40
 Benign : extremely high survival rate 94% at 10
years
 Most common astrocytoma in children are of a
specific type: Juvenile Pilocytic Astrocytoma
(JPA): grade I WHO
02-Mar-16 55

56. Cerebellar Astrocytoma
 Symptoms: early morning headache and
vomiting
 Originate in midline, 30% extend into
cerebellar hemispheres
 25% are solid
 Malignant transformation is exceeding rare
 Gross total resection is curative
 Tumors non surgically accessible: stereotactic
radiosurgery
02-Mar-16 56

57. cerebellar astrocytomas- Pathology
 Most cerebellar astrocytomas are low grade
neoplasms
 These are divided into two pathologic
entities.
◦ Pilocytic astrocytomas are WHO grade I lesions
-65% to 85%
 a biphasic appearance, with compact areas composed
mainly of bipolar cells with hair-like projections
◦ Diffuse astrocytomas are considered as WHO
grade II -15% to 35%.
 fibrillary neoplastic astrocytes on the background of
loosely structured tumor matrix.
02-Mar-16 57

58. Pilocytic astrocytoma- IMAGING
Four predominant imaging patterns :
 Mass with a nonenhancing cyst and an intensely enhancing
mural nodule (21%)
 Mass with an enhancing cyst wall and an intensely enhancing
mural nodule (46%)
 Necrotic mass with a central nonenhancing zone (16%), and
 Predominantly solid mass with minimal to no cyst like
component (17%)
MRI
 Signal characteristics include:
 T1: iso to hypointense solid component compared to adjacent
brain
 T2: hyperintense solid component compared to adjacent brain
02-Mar-16 58

59. Pilocytic astrocytoma- IMAGING
 MRI
 Signal characteristics include:
 T1: iso to hypointense solid component
compared to adjacent brain
 T2: hyperintense solid component compared
to adjacent brain
02-Mar-16 59

60. 02-Mar-16 60

61. (A)MRI T1,
(B) MRI gadolinium
images showing
sellar pilocytic
astrocytoma,
(C) MRI T1,
(D) MRI gadolinium
images showing
cerebellar
pilocytic
astrocytoma
02-Mar-16 61

62. Pilocytic astrocytoma-
TREATMENT
 Surgical resection of cerebellar pilocytic astrocytomas
is considered the treatment of choice
 Resection of mural nodule – key surgical objective
 Resection of cyst wall – controversial ??
 Radiation therapy is strictly avoided, given its risk of
causing significant morbidity in children younger than
5 years of age
 Long-term prognosis is dependent on
◦ the extent of resection,
◦ presence of brain stem invasion and histological features of
malignancy
02-Mar-16 62

63.  Brain stem gliomas (BSG) include glioma
occuring in the midbrain, pons and medulla.
 75 % occur in children
 25% in adults.
 Median age of presentation in childhood is 6.5
years
(75% occur in pts younger than 20 years of age
peak incidence between age of 5 to 10 years)
 No sex predilection
Kaplan AM, Albright AL, Zimmerman RA, Rorke LB, Li H, Boyett JM, et al.
Brainstem gliomas in children. A Children's Cancer Group review of 119
cases. Pediatric neurosurgery 24:185-192,1996
Brainstem gliomas (BSG)
02-Mar-16 63

64. 02-Mar-16 64

65. HALLMARKS OF BSG
 Bilateral long tract signs
 Bilateral multiple contiguous cranial nerve palsies
 Horner’s syndrome
 Inter Nuclear Ophthalmoplegia
 Focal tumors tend to have a slow progression to
neurologic signs in contrast to diffuse malignant
tumors, which have a fast progression to neurologic
signs.
02-Mar-16 65

66. BSG……Classification
 The most recent classification system by
Choux et al based on both CT and MRI
imaging
◦ Type I – Diffuse
◦ Type II – Intrinsic, focal
◦ Type III – Exophytic, focal
◦ Type IV – Cervicomedullary
◦ Pediatric Neurosurgery. New York, Churchill Livingstone, 2000, pp 471–491.
02-Mar-16 66

67. BSG……
 Type I : Diffuse brainstem gliomas
 75% of all BSG
 Hypointense on CT
 No significant enhancement on MRI.
 Characterized by diffuse infiltration and
 swelling of the brainstem.
 Typically, are malignant fibrillary
 astrocytomas (WHO grade III or IV).
02-Mar-16 67

68. BSG……
Type II : Focal intrinsic tumors ( cystic/solid )
 Sharply demarcated from surrounding tissue on
MRI and are associated with less brainstem edema.
 Majority of these lesions are low grade gliomas
(WHO I or II).
 Contrast enhancement : variable
Type III : Exophytic tumors that arise from the
subependymal glial tissue of the fourth ventricle
and mostly grow dorsally or laterally.
 MRI characteristics similar to type II lesions,and
histologically, these lesions are usually low-grade
lesions (WHO I or II) like type II lesions.
02-Mar-16 68

69. BSG……
 Type IV lesions are cervicomedullary
brainstem gliomas.
 Imaging, histology and behavior : similar to
intramedullary spinal cord gliomas.
 Majority are low-grade, non-infiltrative
tumors.
02-Mar-16 69

70. Diffrence between paediatric and adult BSG
In children,
 commonest were pyramidal
weakness (83.1%), palatal
palsy (69.2%), gait ataxia
(47.9%), facial palsy
(80.3%), cerebellar signs
(76.1%).
 Raised ICP and papilledema
seen 20%
 Rapid onset
 Most frequent site in both
adults and children is pons
 Diffuse pontine glioma long
term survival of < 1 year.
In adults
 Facial palsy (86.7%) and
pyramidal weakness (83.3%)
palatal palsy (80%) and
cerebellar signs (76.7%).
 Raised ICP and papilledema
seen 40%.
 Slower in adults.
 Preferece to pons is less
striking.
 Diffuse pontine glioma of
adults is more often grade-2
lesion and is far more
radiosensitive , associated
with a long term survival of
7.3 years02-Mar-16 70

71. Brainstem Tumors: Medullary
15 years old male. JPA confirmed
02-Mar-16 71

72. Brainstem Tumors: Pontine
9 years old male. Glioma grade II WHO02-Mar-16 72

73. Brainstem Tumors:
Mesencephalic
19 years old
female. JPA
02-Mar-16 73

74. Brainstem: Quadrigeminal plate
16 years old female
02-Mar-16 74

75. BSG…..Management
 Biopsy : only for indeterminate lesions
 Stereotactic biopsy: can provide diagnostic tissue.
 Stereotactic radiosurgery
 Not without risk:
Damage to the cranial nerves and long tracts Tissue
heterogeneity
 Focal brain stem tumors are considered amenable to
surgical resection, which is often the primary treatment
of choice.
 Dorsal midbrain tumors, such as tectal gliomas known
to be indolent and stable clinically and radiographically
for many years, may be observed
02-Mar-16 75

76. 02-Mar-16 76
BSG…..Management

77. Choroid Plexus Tumors
 Neoplasms of the choroid plexus.
 Lateral ventricles : most common location in children.
 4th ventricle : most common location in adults.
 4-6% of the intracranial neoplasms in children younger
than 2 years.
 Choroid plexus tumors
◦ Choroid plexus papilloma (WHO Grade 1)
◦ Atypical choroid plexus papilloma (WHO Grade
2)
◦ Choroid plexus carcinoma (WHO Grade 3)
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78. Choroid Plexus TUMORS…..Clinical
 Hydrocephalus and raised ICT
 The tumor itself can cause mass effect.
 Surgery may not resolve HCP
(derangement of reabsorption mechanisms or blockage at other
sites in the ventricular system)
 Treatment of hydrocephalus must be considered both
before and after any surgical procedures.
 An acute increase in ICP : V P Shunt.
 Hydrocephalus often resolves following removal of
the mass.
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79. Choroid Plexus Papilloma…Management
 Total surgical resection is the goal.
 Complete removal: generally curative in papilloma
 Choroid plexus carcinoma -total resection leads to
the best possible outcome.
 Adjuvant CT and RT have been demonstrated to
increase survival
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80. Dermoid cyst
 Congenital ectodermal inclusion cysts.
 Extremely rare < 0.5% of primary intracranial
tumors
 Midline sellar, parasellar, or frontonasal regions :
most common sites.
 Posterior fossa ( vermis or within the 4th
ventricle)
 Growth can lead to rupture of the cyst contents,
causing a chemical meningitis that may lead to
vasospasm, infarction, and even death
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81. Dermoid cyst
 Well-defined, lobulated, “pearly” mass of variable size.
 Characteristically - cyst contains thick, disagreeable, foul
smelling, yellow material
 due to the secretion of sebaceous glands and
 desquamated epithelium
 The cysts may also contain hair and/or teeth
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82. Atypical rhabdoid teratoid tumor
 Younger age than PNET
 Median age at diagnosis less than 2 years of age
 Lack of response to standard therapy
 Special microscopic techniques
 Rhabdoid cells: small round cells (only a
minority of the tumor)
 Cerebellum most common site
 May spread through the subarachnoid space
 Imaging similar to medulloblastoma,
calcification is common, necrosis, cysts and
hemorrhage
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83. 02-Mar-16 83

84. Treatment
Tumor Type Surgery XRT Chemo
Medulloblastoma +++ CrSp +++
Low grade astro +++ focal ----
cerebellar +++ ???? ----
High grade astro/GBM +++ +++ ?
Brain stem glioma (exophytic) focal ?
Ependymoma +++ focal ----
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85. TREATMENT OF ASSOCIATED
HYDROCEPHALUS
 Some advocate Initial placement of VP shunt or EVD prior to
definitive surgery (waiting ≈ 2 wks before surgery) because of
possibly lower operative mortality.
 Theoretical risks of using this approach include the following:
1. Placing a shunt is generally a lifelong commitment, whereas not
all patients with hydrocephalus from a p-fossa tumor will require
a shunt
2. Possible seeding of the peritoneum with malignant tumor cells
e.g. with medulloblastoma.
3. Some shunts may become infected prior to the definitive surgery
4. Definitive treatment is delayed, and the total number of hospital
days may be increased
5. Upward transtentorial herniation may occur if there is excessively
rapid CSF drainageAccordingly,
 Most centers are using a combination of corticosteroids, early
surgery, and external ventricular drainage rather than VP shunting
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86. ETV- role in m/m
 ETV, prior to posterior fossa surgery, reduces the
incidence of hydrocephalus because preoperative
normalization of CSF hydrodynamics decreases
the risk of permanent postoperative impairment
of the CSF circulation.
 However, the routine application of preoperative
ETV is not indicated because of the small
number of patients requiring definitive treatment
for hydrocephalus.
 ETV may be used for persistent or progressive
hydrocephalus following tumor removal.
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87. CONCLUSION
 Pilocytic astrocytoma bears the best outcome.
 Management of hydrocephalus still remains
controversial.
 Though surgery and RT remains the treatment of
choice for medulloblastoma; optimal craniospinal
radiation dose remains debatable.
 Outcome for brainstem gliomas remains dismal.
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88. Thank You
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