CNS Tumors

Question 1

classification of tumors

Answer 1

neuroepithelial tumors
choroid plexus tumors
neuronal tumors
tumors of the pineal regions
embryonal tumors
tumors of cranial nerves
tumors of meninges
sarcoma
lymphoma
germ cell tumor
tumors of sellar region
Metastatic tumors

Question 2

what are the types of neuroepithelial tumors?

Answer 2

its called glioma and divided into 3 different types
1)astrocytoma
2)ependymal tumors
3)oligodendroglioma

Question 3

mention all the types and grades of astrocytic tumors

Answer 3

they can be infiltrating astrocytomas like
diffuse astrocytoma grade 2
anaplastic astrocytoma grade 3
glioblastic astrocytoma grade 3
and it can be localized astrocytoma like
pliocytic astrocytoma which is grade 1 (benign)

Question 4

name the type of ependymal tumors

Answer 4

ependymoma lining the ventricles

Question 5

name the type of embryonal tumors(undifferentiated)

Answer 5

medualloblastoma grade 4 in children

Question 6

what are the types of cranial nerve tumors

Answer 6

schwannoma
neurofibromma
malignant peripheral tumor of neuronal sheath

Question 7

tumors of the meninges

Answer 7

meningioma

Question 8

what are the 2 types of tumors of sellar region

Answer 8

pituitary adenoma
craniopharyngioma

Question 9

what are the general features of CNS tumors

Answer 9

3/4 are primary tumors and 1/4 are metastatic tumors
20%occurs in children
70% occurs in the cerebral hemispheres in adults
in children it occurs in posterior cranial fossa and cerebellum
any brain tumor that occurs in a critical region will cause death.
brain tumors rarely metastasis but can spread through the csf to the subarachnoid space

Question 10

what are the most common types of tumors in children

Answer 10

medulloblastoma
ependymoma
pilocytic astrocytoma

Question 11

what are the clinical manifestations of CNS tumors

Answer 11

increase in intracranial pressure
seizures
neurological deficit according to the anatomical site

Question 12

describe gliomas

Answer 12

infiltrating gliomas have tendencies to develop from low grade to high grade lesions with time
some tumors like infiltrating astrocytoma and oligodenroglioma may infiltrate a large region of the brain so their curing is impossible
diffuse astrocytoma account for 80% of gliomas in adults they are most frequent in the fourth through six decade of life they are usually found in the cerebral hemispheres

Question 13

describe garde 2 and garde 3 astrocytoma

Answer 13

they are grey poorly defined infiltrative doesn’t form discrete mass firm or soft gelatinous and cystic degeneration may be seen

Question 14

describe glioblastoma

Answer 14

variation of appearance from region to another is characteristic.
some areas are firm and white and others are soft and yellow and that because tissue necrosis other regions show cystic degeneration and hemorrhage

Question 15

describe the pilocytic astrocytoma

Answer 15

relatively benign tumors that typically affect children and young adults mainly found in the cerebellum they may also involve the third ventricle spinal cord and occasionally the cerebral hemispheres. there is a cyst often associated with it

Question 16

describe ependymomas

Answer 16

they most often arise next to ependymal cells lining the ventricular system in addition to central canal of the spinal cord. in the first 2 decades of life they are found in the 4th ventricle and constitute 5-10% of primary brain tumors in this age group in adults its mostly found around the spinal cord

Question 17

where are the most common primary sites of metastatic lesions?

Answer 17

1)kidney
2)skin
3)lung
4)breast
5)gastrointestinal tract

Question 18

metastases form sharply demarcated masses at the grey-white matter junction and elicit local edema

Question 19

describe medulloblastoma

Answer 19

it occurs predominantly in children and exclusively in the cerebellum its highly malignant and prognosis of untreated patient is poor
in children it occurs at the midline of the cerebellum while at the lateral side is more common in adults
the tumor is well circumscribed and grey and friable and may be seen extending to the surface of the cerebellar folia and involving leptomeninges

Question 20

describe meningiomas

Answer 20

they are predominantly benign tumors that arise form arachinoid meningiothelial cells , they usually occurs in adults and attaches to dura.
meningiomas may be found along the whole external surface of the brain as well as the ventricular system where they arise from the stromal arachnoid cells of choroid plexus