Extra Neoplasm Info Flashcards
neoplasm
disorder of cell growth that is triggered by a series of mutations that give the cells a survival and growth advantage that is independent of growth regulation signals (autonomous) and allows clonal cell expansion
“tumor”: then and now
- used to refer to swelling of tissue in inflammation
- now synonymous with neoplasm
Features of neoplasia induction
- stimulus results in changes in the cell/tumor that persist after stimuli are gone
- genetic alterations occur that are passed down to the progeny of the tumor cells
- genetic changes allow excessive and unregulated proliferation that becomes autonomous (independent of physiologic growth stimuli)
- pop of neoplastic cells arise from a single cell that has incurred the genetic changes (clonal expansion)
differentiation
the extent to which neoplastic parenchymal cells resemble normal parenchymal cells
histologic chars. of squamous carcinoma in situ
- thickened epithelium
- persistence of large nuclei throughout epithelial layer
- not normal squamous differentiation
- marked dysplasia and anaplasia
- uneven nuclear size and hyperchromatic due to more nuclei in cells
- NOT invading BM
- islands of squamous differentiation and keratinization
Histologic chars. of squamous cell carcinoma
- sheets/cords of pleomorphic/anaplastic epithelial cells invading into surrounding tissue and breaking through BM
- tumor cells stick together via desmosomes, which can be faintly seen!
- islands of neoplastic cells below epidermis in dermis/submucosa
- dysplastic and anaplasmic cells undergoing squamous differentiation and kerratinization (KERATIN PEARLS)
- clusters of epithelial cells invading stroma and inducing fibrosis
horses commonly have benign thyroid follicular adenomas
:)
describe pulmonary adenocarcinoma histologically
- normal alveolar architecture destroyed
- acinar-like formations of epithelial cells
- coag necrosis possible
- cells no longer show polarity and show considerable anaplasia
- cells undergoing mitosis
- tumor emboli in lymphatics*
- tumor cells growing on pleural surface
- spherous response in mesenteric fat
- invasion of arteries and veins causing coagulation, platelet aggregation, and thrombosis
most common tumor in rats
fibroadenoma
- driven by hormonal stimulation
- seen in rats w/ prolactin-producing pituitary adenomas
- induces angiogenesis
mixed tumor
single neoplastic parenchymal clone gives rise to multiple cell types
teratoma
neoplasm with multiple germ layers
examples of mesenchymal/hematopoietic neoplasms
- fibrosarcoma
- hemangioma/hemangiosarcoma
- mast cell tumor
histo features of fibrosarcoma
- cells arranged in large sheets
- spindle shaped cells
- collagen strands
- invasion via blood vessels*
do fibrosarcomas usually metastisize?
no. They usually only invade surrounding structures
how do fibrosarcomas usually invade?
via blood vessels
histo features of hemangiosarcoma
- look very bloody
- form channels that fill with blood
histo features of mast cell tumor
- dense arrays of relatively normal mast cells that usually have granules
- induce soft masses due to histamine release
most common cause of death in dogs
cancer (2nd most common in humans)
interactions between what factors determine cancer risk?
environmental and genetic.
role of reparative proliferation in cancer?
tissue inflammation, hyperplasia, immunodeficiency increase risk for cancer
common genetic themes in cancer
1) nonlethal genetic damage is central
2) tumors are clonal expansions of a single precursor cell that has incurred genetic damage
3) 4 classes of regulatory genes are principal targets in most cancers
4) carcinogenesis results from the accumulation of complementary mutations over time
cellular and molecular hallmarks of cancer
- self sufficiency of growth signals
- insensitiviy to growth-inhibitory signals
- altered cellular metabolism
- evasion of apoptosis
- sustained angiogenesis
- ability to invade and metastasize
- ability to evade host immune defenses
Warburg effect
upregulates anaerobic glycolysis in cancer cells by switching from oxygen metabolism with mitochondria to a glycoprotein pathway, which allows more intermediates to be shoved into protein/NA/membrane lipid synthesis
T/F: VEGF inhibitors can be used in cancer treatment
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