NP3E

Question 1

Tumors can arise from cells in the nervous system

Answer 1

primary tumors

Question 2

Tumors can spread to the nervous system via the blood supply or by direct extension

Answer 2

secondary tumors

Question 3

Is the process whereby a normal cell acquires the capacity for autonomous growth. The resultant neoplastic cell is no longer sensitive to growth inhibitory influences within its environment.

Answer 3

Carcinogenesis

Question 4

Carcinogenesis occurs in a series of steps:

Answer 4

Initiation
Promotion
Progression

Question 5

Alteration of the genetic information of a cell occurs, being fixed by a round of replication

Answer 5

Initiation

Question 6

The genetic alteration is ultimately expressed as unique cellular characteristics (phenotype) following additional rounds of replication. For certain of these cells, the new phenotype confers a selective advantage to survival over its neighbors and we call this the resistance phenotype. Additional alterations to the genetic information may occur during this time, each fixed by a round of replication. As a result, mature neoplasms have multiple mutations, which is why the initial causative change can be so hard to pin down.

Answer 6

Promotion

Question 7

Further replication in an environment otherwise inhibitory to autonomous growth drives a survival of the fittest evolutionary process for the altered cells. A neoplastic cell is a result.

Answer 7

Progression

Question 8

In general, approximately ______ of tumors are primary – secondary tumors are common

Answer 8

50%

Question 9

___________ tumors are common.

Answer 9

meningeal

Question 10

Other mesenchymal tumors such as lymphoma can be a _____________ although careful examination of other tissues must be performed to rule out the involvement of other organ systems

Answer 10

primary tumor

Question 11

_________ tumors are less common, but they do occur

Answer 11

Glial

Question 12

Why don’t tumors arise from differentiated neurons?

Answer 12

because neuronal differentiation is terminal

Question 13

Tumors can arise from undifferentiated stem cells in the _______

Answer 13

young

Question 14

a group of tumors defined by their appearance and are thought to develop from primitive (undeveloped) nerve cells in the brain

Answer 14

Primitive Neuroectodermal Tumors (PNET)

Question 15

In a cat with an intracranial tumor, greater than ______will be primary and _____ of those will be meningiomas

Answer 15

70%, 58%

Question 16

If a tumor looks like it’s composed of astrocytes, then we assume it is derived from the astrocytic lineage

Answer 16

astrocytoma

Question 17

If it looks like it is arising from the meninges, it’s likely a _____________

Answer 17

meningioma

Question 18

If it is arising from the parenchyma, it is likely an ______________ or __________

Answer 18

oligodendroglioma or astrocytoma

Question 19

If it is arising from the lining of a ventricle, it may be either a ___________ or an ___________

Answer 19

choroid plexus tumor, ependymoma

Question 20

A tumor in the posterior fossa of a young animal might be a __________

Answer 20

PNET

Question 21

If there are multiple masses, then it is likely a ______________

Answer 21

secondary tumor

Question 22

A ______________ should be a differential for a single mass

Answer 22

granuloma

Question 23

Differentials for multiple masses would be ______________or _______________

Answer 23

secondary tumors, granulomatous inflammation

Question 24

Tumors of _________ or the ________ can involve the nervous system by direct extension

Answer 24

bone, pituitary

Question 25

_________tumors in other organ systems are well differentiated, sharply demarcated from adjacent tissues, and may even be encapsulated by fibrous connective tissue

Answer 25

Benign

Question 26

___________ tumors are less well differentiated, exhibit atypical cell morphologies, and may spread by direct extension (infiltrative growth) or metastasis

Answer 26

Malignant

Question 27

In the ______________, any rapidly growing tumor is considered to be “malignant” because of the consequences of rapid growth

Answer 27

nervous system

Question 28

histological criteria differ to a degree, in that slowly growing “benign” _________tumors are never encapsulated and may exhibit infiltrative growth along their perimeter

Answer 28

glial

Question 29

Indicators of aggressive biological behavior in nervous system tumors:

Answer 29

• lack of differentiation
• atypia
• evidence of rapid growth
• metastasis

Question 30

Cells with variability in nuclear size and shape, multinucleated cells, and mitotic figures that represent cells that get stuck in variable stages of cell division

Answer 30

atypia

Question 31

Vascular proliferation (to feed the tumor), necrosis (where the tumor outgrew its blood supply) and a high mitotic index

Answer 31

evidence of rapid growth

Question 32

Tumors growing into the ventricles may shed neoplastic cells and spread throughout the ventricular system. This is seen with choroid plexus tumors and oligodendrogliomas.

Answer 32

metastasis

Question 33

Indicators of more aggressive biological behavior are reflected in the diagnosis. A tumor of astrocytic origin would be considered a high grade or anaplastic ____________. In the extreme, it would be called a __________

Answer 33

astrocytoma, glioblastoma

Question 34

A ____________ tumor can be clinically silent or unnoticeable for months or years. It is when the tumor triggers a response such as an edema cycle that clinical signs become overt

Answer 34

nervous system

Question 35

ischemic necrosis of grey matter, herniation and death

Answer 35

The edema cycle

Question 36

Hydrocephalus for a tumor that obstructs ______ flow

Answer 36

CSF