Ch 7 Neoplasia

Question 1

What does a single mass generally suggest in the context of CNS tumors?

Answer 1

Primary CNS tumor

Question 2

What is the typical appearance of a choroid plexus tumor?

Answer 2

Red with granular roughened texture

Question 3

What imaging characteristic is associated with high grade glioma?

Answer 3

Whitish yellow areas of necrosis and variegated hemorrhage

Question 4

What IHC markers are used in the diagnosis of CNS tumors?

Answer 4

IHC markers and TEM

Question 5

What is the WHO grade for pilocytic astrocytoma?

Answer 5

Grade I

Question 6

What MRI characteristics are associated with pilocytic astrocytoma?

Answer 6

T2 hyperintense and strong contrast enhancement with multiple small cysts

Question 7

What cells are typically found in a subependymal giant cell astrocytoma?

Answer 7

Gemistocytic, spindle, and ganglioid-like astrocytoma cells

Question 8

What is the PI for subependymal giant cell astrocytoma?

Answer 8

Less than 2%

Question 9

What grade of tumor is a diffusely infiltrating astrocytoma classified as?

Answer 9

WHO grade II

Question 10

What is the typical location of diffuse astrocytoma?

Answer 10

Frontal and temporal lobes

Question 11

What is a key feature of anaplastic astrocytoma?

Answer 11

Marked increased cellularity and nuclear atypia

Question 12

What is the most malignant form of astrocytoma?

Answer 12

Glioblastoma (grade IV)

Question 13

What MRI findings are associated with glioblastoma?

Answer 13

Central areas of hypodense necrosis with contrast ring enhancement

Question 14

What is a characteristic feature of gliomatosis cerebri?

Answer 14

Widespread diffuse, uniform, confluent, bilateral growth

Question 15

What is a major predilection site for oligodendroglioma?

Answer 15

Frontal, parietal, and temporal lobes

Question 16

What is the MRI appearance of oligodendroglioma?

Answer 16

T1 hypointense, markedly T2 hyperintense

Question 17

What histological feature is characteristic of oligodendroglioma?

Answer 17

Monomorphic densely packed cells with uniform round basophilic nucleus

Question 18

What is the minimum percentage of either cell type required for a diagnosis of oligoastrocytoma?

Answer 18

At least 30%

Question 19

What is a key imaging feature of ependymoma?

Answer 19

T1 hypointense, T2 markedly hyperintense with intense heterogeneous contrast enhancement

Question 20

What is a defining characteristic of choroid plexus tumors?

Answer 20

Granular, rough texture, gray to reddish mass

Question 21

What is the main subtype of ganglioma/gangiocytoma?

Answer 21

Mature ganglionic-like multipolar neurons

Question 22

What is a common feature of medulloblastoma?

Answer 22

Densely cellular with ovoid, elongate to round deeply basophilic nuclei

Question 23

What is the common feature of schwannoma?

Answer 23

Benign, slow growing, encapsulated

Question 24

What is the histological type of Antoni type A schwannoma?

Answer 24

Compact, long, bipolar spindle cells

Question 25

What defines malignant peripheral nerve sheath tumors (PNST)?

Answer 25

Lack epineural tumor capsule and may aggressively invade surrounding structures

Question 26

What is a key feature of primary lymphoma in the CNS?

Answer 26

Concentric bands of reticulin within angiocentric infiltrates

Question 27

What is a defining characteristic of primary CNS histiocytic sarcoma?

Answer 27

Single, large, broad-based masses

Question 28

What is the typical presentation of germinoma?

Answer 28

Large cells in sheets or lobules with large nuclei

Question 29

What is the age group commonly affected by ectopic nephroblastoma?

Answer 29

Young dogs

Question 30

Fill in the blank: Choroid plexus tumors in dogs comprise about ______ of all primary tumors.

Answer 30

7%

Question 31

What is the typical immunoreactivity for choroid plexus carcinoma?

Answer 31

CKC (Lu-5), E-cadherin, variably GFAP

Question 32

What type of tumors tend to involve meninges, gray over white matter?

Answer 32

Metastatic tumors