exam 3 neoplasia part 2 Flashcards
cell cycle
What is the MDx of this neoplasm if it is malignant and involves sqaumous cells?
squamous cell carninoma
All
Oncogene mutations are dominant meaning ???
only need one to gain function uncontrolled growth
A mutation with what gene is present in 20% cases of dogs with mast cell tumors
ckit
_____ is the result of certain heritable changes in the DNA of tumor cells.
neoplasia
4 types of abnormalities that can lead to neoplasia
defective DNA repair
self suffiecient growth signals
insensitivity to growth inhibition signals
evasion of apoptosis
Tumor suppresor genes are ___ meaning the need 2 independent mutations to occur for cells to not be sensitized to growth inhibition signals
recessive
p53 is an example of a ___
tumor suppressor gene
Most common mutation is human neoplasm
mutation with p53 because we only have 1 copy
Elephants have less instances of cancer than people because???
they have more copies of p53
D
Tumor is intially made from clonal daughter cells of the first mutted cell. Then more mutations are aquired as genetic instability increases. Malignant cells being treated with chemo/radiation pose what risk if you dont kill all cancer cells?
selective for malignany that is resistent to treatment
Malignant tumor on spleen with an endothelial origin. Whats MDx?
splenic hemangiosarcoma
Malignant metastisis to the lungs of an endothelial origin. Mdx?
pulmonary metastatic hemangiosarcoma
Adult white cat presents with thickened firm crusty erosion on nose. Predisposition for what cancer in situ?
squamous cell carcinoma in situ
Which is squamous cell carcinoma in situ and which is squamous cell carcinoma? How can you tell?
L = in situ
R= malignant
It has more cell types (mutations and it is invasive)
This invasion is characteristic of what type of metastisis mutation characterized by cells not respecting anatomical borders
loss of contact inhibition
What are the four stages of migration leading to metastisis.
1) loosen cell jxn decreased expression of cadherins
2) degradation by cleavage of matrix components
3) attachment increased expression of laminin, collagen, fibronectin receptors
4) growth factors follow chemotaxis
This is a histopath of an adult cat mammary tumor. Regarding this tumor, which is/are true:
A. It is a carcinoma
B. It could be benign
C. It has metastasized
D. None are true
it is a carcinoma more likely malignant than a similar tumor in a dog, invaded into the blood vessel not metastisized
What is the difference between normal angiogenisis and tumor angiogenisis?
Vascular endothelial growth factor meshwork and leaky
What are the three types of spreading for metastisis neoplasms?
transcolemic
hematogenous
lymphatics
What type of cancers favor hematogenous spread?
sarcomas
What type of cancers favor lymphatics?
carcinomas
Hematogenous and lymphatic spread neoplasms arrest in the first capillary bed encountered. For many tumors this is in the ____, but for enteric tumors this is the ____
lung
liver
term for bone metastisis occuring with mammary and prostate carcinomas.
organotropism
pulmonary carcinomas often metastisize in the ___ of a cat
digit
yes spontaneous regression of histyocytoma by lymphocyte attack
Immune system is capable of recognizing self-antigens expressed on tumor cells and attacking these cells
immunesurveilance
4 ways neoplasms can evade the immune system
- Altered MHC expression
- Loss or masking of tumor-specific antigens
- Tolerance – especially if the antigen is shared with normal tissues
- Immunosuppression – Fas ligand stimulates apoptosis of binding T cells
3 mechanisms of altering DNA
