CNS Tumours

Question 1

CNS tumours originating from glial cells?

Answer 1

1. Astrocytoma
2. oligodendroglioma
3. ependymoma
4. glioblastoma

Question 2

CNS tumours originating from Primitive neuroectodermal cells?

Answer 2

1. Medulloblastoma
2. neuroblastoma

Question 3

CNS tumours originating from Arachnoidal cells?

Answer 3

meningioma

Question 4

CNS tumours originating from nerve sheath cells?

Answer 4

Schwannoma
neurofibroma

Question 5

CNS tumours originating from lymphoreticular cells?

Answer 5

lymphoma

Question 6

CNS tumours in children?

Answer 6

1. astrocytoma
2. medulloblastoma
3. ependymoma
4. others

Question 7

CNS tumours in adults?

Answer 7

1. glioblastoma
2. meningioma
3. astrocytoma
4. schwannoma
5. others

Question 8

Epidemiology of CNS tumours?

Answer 8

Second commonest tumours in children and the sixth commonest in adults

Question 9

Symptoms of CNS tumours?

Answer 9

Present with localising signs due to:
1. tissue destruction
2. non-specific effects of raised intracranial pressure

Question 10

Locations for CNS tumours?
Adults?
Children?

Answer 10

1. In children
   - 70% are sited in the posterior fossa
   - most are intrinsic tumors
2. In adults
   - 70% are sited supratentorially
   - intrinsic and extrinsic tumors both occur frequently

Question 11

Metastatic tumours?

Answer 11

Metastatic tumors occur more frequently with increasing age: most are carcinomas
- which may form solid deposits in the CNS or spread by seeding in the CSF
Note: Survival depends on the age of the patient and the site, size and histology of the neoplasm

Question 12

Pathogenesis of CNS tumours?

Answer 12

1. Genetic
2. Chemical & viral
3. Radiation - ? Mobile phones
4. Immunosuppression – primary cns lymphomas
5. Trauma – role unproven

Question 13

Brain tumors clinically present in what two main ways?

Answer 13

1. Local effects – focal neurological signs
   e.g. epilepsy or paraplegia
2. Mass effects – non specific signs & symptoms of space occupying lesion
   > herniation being the common cause of death

Question 14

Name intrinsic tumours?

Answer 14

1. Astrocytoma
2. Glioblastomas
3. Oligodendroglioma
4. Ependymomas
5. Choroid plexus papillomas
6. Hemangioblastomas
7. Lymphomas
8. Primitive neuroectodermal tumors
9. Medulloblastoma

Question 15

Epidemiology of astrocytoma?

Answer 15

10% of all primary adult CNS tumors, relatively more frequent.

Question 16

Sites for astrocytoma?
Adults?
Children?

Answer 16

1. cerebellum in children
2. cerebral hemisphere in adults

Question 17

Astrocytoma is classified according to?

Answer 17

1. predominant cell type
2. degree of differentiation

Question 18

Prognosis for astrocytomas involve?

Answer 18

1. degree of differentiation
2. age of patient
3. site & size

Question 19

Microscopy of astrocytoma?

Question 20

Epidemiology of glioblastoma?

Answer 20

30 % of all primary CNS tumors, rare in children

Question 21

Location of glioblastoma?

Answer 21

Arise in white matter of cerebral hemispheres
- Dedifferentiate from pre-existing astrocytomas

Question 22

Prognosis of glioblastomas depends on?

Answer 22

1. degree of differentiation
2. age of pt
3. site & size

Question 23

Microscopy of glioblastoma?

Question 24

Epidemiology of medulloblastomas?

Answer 24

Commonest primitive neuroectodermal tumor

Question 25

Location of medulloblastomas?

Answer 25

Arises in cerebellum of children

Question 26

Pathology of medulloblastomas?

Answer 26

Rapid growth with extensive infiltration resulting in obstructive hydrocephalus CSF seeding common

Question 27

Prognosis of medulloblastomas depends on?

Answer 27

With radiotherapy, prognosis has improved 5yr survival rate is 60%.

Question 28

Microscopy of meduloblastoma?

Question 29

Name extrinsic tumours?

Answer 29

1. Meningioma 2. Schwannoma 3. Neurofibroma

Question 30

Epidemiology of meningiomas?

Answer 30

18% of intracranial neoplasms in adults Female>male 2:1

Question 31

Sites of meningiomas?

Answer 31

parasagittal region, sphenoid wing, olfactory groove & foramen magnum

Question 32

Macroscopy of meningiomas?

Answer 32

Smooth lobulated broadly adherent to dura May infiltrate dura & bone, exceptionally invade brain May markedly compress the brain

Question 33

Histology of meningiomas?

Answer 33

Displays a variety of patterns Occasionally malignant, and may metastasize outside the CNS

Question 34

Metastatic CNS tumours?

Answer 34

CNS common site for metastasis Hematogenous or direct spread Carcinomas are the most common particularly from ; breast, bronchus, kidneys and colon , and malignant melanomas. Often lodge at the boundary betwn grey & white matter. Infiltration of subarachnoid space may produce carcinomatous meningitis