L3

Question 1

Majority of Tumor of brain are :

Answer 1

Primary

Question 2

The unique characteristic features of CNS tumors

Answer 2

1. do not have morphologically evident premalignant or in situ stages
2. Low grade tumors may infiltrate large regions of the brain and may lead to serious clinical deficits
   (poor prognosis)
3. anatomic site of tumor may influence the outcome due to local effects (benign meningioma may cause
   cardiorespiratory arrest from compression of medulla)
4. Even highly malignant tumors of CNS rarely spread outside the CNS

Question 3

CLASSIFICATION OF INTRACRANIAL TUMORS

Answer 3

• FROM CELLS OF BRAIN (GLIAL, NEURONAL)

• EMBRYONAL (PRIMITIVE) NEOPLASM (MEDULOBLASTOMA)

• FROM OTHER POPULATION OF CELLS IN BRAIN ( LYMPHOID CELLS, GERM CELL)

• FROM MENINGES ( MENINGOTHELIAL CELLS)

• FROM OTHER SITES OF BODY (METASTATIC)

Question 4

GLIAL TUMORS are:

Answer 4

• ASTROCYTOMA
• OLIGODENDROGLIOMA
• EPENDYMOMA

Question 5

Diffuse Astrocytoma

Answer 5

1-most common (80%) glioma in adults
2-most common location is cerebral hemisphere
3-most common presenting features are seizure, headache, focal neurologic deficit

Question 6

astrocytomas are dividedinto three groups

Answer 6

• Diffuse astrocytoma (grade II)
• Anaplastic astrocytoma (Grade III)
• Glioblastoma ( grade IV)

Question 7

1-poorly defined, gray, infiltrative tumors
2-invaded brain without forming a discrete mass
3- cut surface of the tumor is either firm or soft and gelatinous
4- Cystic degeneration may be present

Answer 7

Grade II and III astrocytomas

Question 8

1-some areas are firm and white, others are soft and yellow due to necrosis.
2-Cystic degeneration and hemorrhage may be present

3-necrosis (often with pseudopalisading nuclei) or microvascular proliferation.

Answer 8

Glioblastoma ( grade IV )

Question 9

characterized by:
1-mild to moderate increase in the number of glial cell nuclei
2- variable nuclear pleomorphism.

Answer 9

Grade II astrocytomas ( diffuse )
بالاضافه للمشترك بينه وبين قريد iii

Question 10

1-show regions that are more densely cellular and have greater nuclear pleomorphism.
2-Mitotic figures are present.

Answer 10

Anaplastic astrocytomas ( grade III)
+ الاشياء المشتركه مع II

Question 11

• Usually in children
• Common site is cerebellum
• Low grade tumor
– microcytic areas
– Rosenthal fibers
– Eosinophilic granular bodies

Answer 11

Pilocytic astrocytoma

Question 12

Oligodendroglioma:

Answer 12

-5 - 10 % of glial tumors
-Most common location is cerebral hemispheres (frontal or temporal lobes )
-Usual presentation is seizure / focal neurologic deficit.

• Grades:
II (Well differentiated)
III (anaplastic)

Question 13

1-infiltrative tumors that form gelatinous, gray masses, and may show cysts, focal hemorrhage, and calcification

2-tumor is composed of sheets of regular cells with spherical nuclei containing finely granular- appearing chromatin surrounded by a clear halo of cytoplasm.

Answer 13

Well-differentiated oligodendrogliomas (grade II)

Question 14

1-most commonly arise in the brain stem (especially in pons) and also occur in the spinal cord and thalamus.
2-have acquired point mutation in histone H3.
3- These are infiltrative tumors and results in significant neurologic impairment.

Answer 14

Midline Glioma

Question 15

-tumors occur near the 4th ventricle in first 2 decades
-Spinal cord is the most common location in adults.
-perivascular pseudorosettes (tumor cells are arranged around vessels with an intervening zone containing thin ependymal processes) are more frequently present.

Answer 15

Ependymoma

Question 16

Neuronal tumors include :

Answer 16

1. Central neurocytoma
2. Ganglioglioma
3. Dysembroplastic neuroepithelial tumors

Question 17

-accounts for 20% of pediatric brain tumors.
-exclusively occurs in cerebellum.
-It is a highly malignant tumor.
-tumors are densely cellular with sheets of small blue cells

Answer 17

Medulloblastoma

Question 18

CNS Lymphoma :

Answer 18

• 1 % of intracranial tumors
• Usually in immunosuppressed individual associated with Epstein Barr virus
• Large B cell lymphoma ( most common type)

Question 19

Germ Cell Tumor

Answer 19

• Age Less than 20 years (in 90% cases)
• Location pineal and Supraceller
• Common type Germinoma

Question 20

tumors usually solitary originates from arachnoid meningothelial cells?

Answer 20

Meningioma(
>
((when present at multiple sites, especially in association with acoustic neuromas or glial tumors, the possibility of neurofibromatosis type 2 should be considered))

Question 21

• grow as well defined durabased masses and may compress the brain but do not invade it?

Answer 21

Meningiomas (Grade I)

Question 22

• have a higher rate of recurrence and
more aggressive local growth. These have increased cellularity and mitotic activity?

Answer 22

Atypical meningioma (Grade II)

Question 23

• These are highly aggressive tumor with the appearance of a high-grade sarcoma, but retaining
some histologic evidence of meningothelial origin. Mitotic rates are high (>20 mitoses per 10 HPF)?

Answer 23

Anaplastic (malignant) meningioma (Grade III).

Question 24

Metastatic tumors common sites ?

Answer 24

1. Lung
2. Breast
3. Skin
4. Kidney
5. Gastrointestinaltract

Question 25

diverse tumors develop ?

Answer 25

paraneoplastic syndromes that involve the peripheral and/or central nervous systems

Question 26

mechanism of paraneoplastic syndromes?

Answer 26

development of an immune responsea gainst tumor antigens that cross-react with antigens in the central or peripheral nervous systems.

Question 27

Paraneoplastic Syndromes ( Subacute cerebellar degeneration ):

Answer 27

• It is associated with destruction of Purkinje cells, gliosis and a mild chronic inflammatory cell infiltrate.
• circulating PCA-1 antibody (anti-Yo) that recognizes cerebellar Purkinje cells.
• This antibody occurs predominantly in women with (ovarian, uterine, or breast carcinoma)

Question 28

Limbic Encephalitis

Answer 28

-subacute dementia and marked by perivascular inflammatory cuffs, microglial nodules, some neuronal loss, and gliosis

-most evident in the anterior and medial portions of the
temporal lobe (the microscopic picture resembles that of an infectious process).

-ANNA-1 antibody (anti-Hu) that recognizes neuronal nuclei in the central and peripheral nervous systems -ANNA-1 is most commonly associated with small cell carcinoma of the lung

Question 29

Familial Tumor Syndromes?

Answer 29

Tuberous sclerosis
Von Hippel-Lindau Disease

Question 30

-autosomal dominant syndrome.
-hamartomas
-benign neoplasms involving the brain and other tissues
-may result from disruption of either TSC1 (which encodes hamartin) or TSC2 (which encodes tuberin)

Answer 30

Tuberous sclerosis

Question 31

Von Hippel-Lindau Disease

Answer 31

-autosomal dominant disease
-develop hemangioblastomas of the CNS and cysts involving the pancreas, liver, and kidneys

-Hemangioblastomas are most common in the -cerebellum and retina-

-associated with (VHL) tumor suppressor gene that down-regulates hypoxia-induced factor 1 (HIF-1)