Neoplasia II Flashcards
What allows for the increased rate of growth in neoplasms (3)?
- Evasion of host control
- Limitless replicative potential
- Loss of contact inhibition
What is the percentage of cell in the cell cycle in normal tissues? Benign neoplasms? Malignant neoplasms?
Normal = 1% Benign = 1-10% Malignant = 20-80%
What happens to apoptotic rates in neoplasms?
Inhibited apoptosis
What are the three factors that we use to measure increased growth rate?
- Doubling time
- Fraction of tumor cells in proliferative pool
- Cell production vs cell loss
How many doubling times are needed for cells to become a mass of 1 g (the clinically detectable amount)?
30 doublings
How many doublings are needed for cells to develop a 1 kg mass (the max compatible with life)?
40 doublings
What happens to the growth fraction in the submicroscopic phase?
High growth fraction
What is the relative growth fraction in later stages of cell growth?
<20%
How do you measure mitotic activity?
No. of mitotic figures / 10 HPF
What is Ki-67?
Cell marker for cell proliferation
What is PCNA?
Proliferating cell nuclear antigen
What are the two marker proteins that are used to identify cell proliferation (in high quantities)?
Ki-67
PCNA
What is the difference between the fragmentation of nuclear chromatin in apoptotic cells, vs normal cells in prophase?
Much more clumped together in apoptotic bodies
What type of cell/when are more susceptible to chemotherapy?
Cells within the cell cycle (high growth rate)
What is differentiation?
Cells or tissues resemble their normal progenitors in both appearance and function
True or false: neoplastic cells within the cell cycle cannot differentiate
True
What does the degree of differentiation of neoplastic cells depend on?
Proportion of cells within the cell cycle
What are the four categories of differentiation?
- Well
- Moderately
- Poorly
- Undifferentiated (anaplastic)
What happens to nuclei in tumors?
pleomorphic
What happens when a capsule around a tumor breaks?
Becomes malignant
Anaplastic = ?
Undifferentiated tissue mass
How can you tell where a tumor came from? (2)
Expression of cell markers (e.g. keratin marks epithelial cell)
Cytological findings
What is polarization? What happens in neoplasms?
Polarization is the orientation of cells
Loss of polarity = disorganization
What causes the loss of polarity in anaplastic cells?
Mutations and lack of differentiation as the cells migrate/proliferate
What are the three diagnostic criteria for cellular atypia?
- Cellular pleomorphism
- Nuclear changes
- increase from 1:1 N/C ratio
What are the nuclear changes in cellular atypia? (4)
- Nuclear pleomorphism
- Dense and irregular nuclear outline
- Nuclear hyperchromicity
- Nucleolar Pleomorphism
What happens to the Nucleus/Cytoplasm ratio in cellular atypia?
Greater than 1:1 (normal is 1:5)
What is hyperchromasia?
Abundant DNA
Extremely dark staining
What is pleomorphism?
Variation is size and shape of cells and nuclei
What is anaplasia?
Term referring to a lack of differentiation
What happens to the nucleoli in tumors?
Gets bigger
What happens to the size of cells in tumors?
Bizarre tumor giant cells
What happens to tissue architecture/function in anaplastic tumors?
Loss of tissue architecture/function = more aggressive
What are giant tumor cells? What do giant tumor cells represent?
Single huge polymorphic nucleus or >2 nuclei
Represent Anaplasia
True or false: mitoses alone is used to define malignancies
False–also cellular atypia
However, more mitoses = more likely malignant
What is desmoplasia?
Hyperplasia of activated fibroblasts, resulting in abundant collagenous stroma
What is the stain used to identify collagen?
Trichrome staining = blue
What are the three proangiogenic factors?
VEGF
bFGF
HIF
What are the four anti-angiogenic factors?
Thrombospondin-1
Angiostatin
Endostatin
Tumstatin
Proangiogenic or antiangiogenic: VEGF
Pro
Proangiogenic or antiangiogenic: thrombospondin-1
Anti
Proangiogenic or antiangiogenic: angiostatin
anti
Proangiogenic or antiangiogenic: HIF
Pro
Proangiogenic or antiangiogenic:bFGF
Pro
Proangiogenic or antiangiogenic: Tumstatic
Anti
Proangiogenic or antiangiogenic: Endostatin
Anti
Why do malignant tumors show central necrosis?
Tumors are limited by the ability of nutrients to diffuse into it, to a diameter of 1-2 mm
(it outgrows its blood supply)
True or false: A tissue with many mitotic cells = malignant CA
False–could be benign
