Lecture 18: Neoplasia I

Question 1

What are the blanked out stages of the cell cycle?

Answer 1

Question 2

What does the term Neoplasia *literally* mean?

Answer 2

Neoplasia = New growth

Question 3

What’s the definition of a neoplasm?

Answer 3

“A neoplasm is an abnormal mass of tissue, the growth of which is uncoordinated with that of the normal tissues and persists in an excessive manner after the cessation of the stimuli which evoked the change.” - Some person named Willis

Question 4

What are the key features of neoplasia?

Answer 4

1. Excessive growth
2. Lack of responsiveness to normal growth controls
3. independent of causal simtulus
4. Heritable from cell to cell

Question 5

What are some of the cytologic criteria of malignancy?

Answer 5

• Anisocytosis
• Anisokaryosis
• Asymmetric mitotic figures
• Multinucleation
• Pleomorphism
• Variable nucleolar size
• Changes in nuclear to cytoplasmic ratio

Question 6

What’s anisocytosis?

Answer 6

Cells of unequal sizes. Same type of cell, but different sizes.

One cytologic criteria of malignancy.

Question 7

Anisokaryosis? Wha?

Answer 7

Variability of nuclear sizes. Kary - nuclear.

One cytologic criteria of malignancy.

Question 8

Pleomorphism?

Answer 8

Refers to variable in cell shape. If you have a pleomorphic population, that means you’re looking at all the same cell population, but they are different shapes/sizes

One cytologic criteria of malignancy.

Question 9

Changes in nuclear to cytoplasmic ratio? What does that mean…?

Answer 9

May have one cell with a huge nucleus and little cytoplasm right next to a cell that has a small nucleus and abundant cytoplasm

One cytologic criteria of malignancy.

Question 10

What are we looking at here? Is this malignant?

Answer 10

Aspirate of an oral malignant melanoma from a dog

We know these cells are all melanocytes from the green/black pigment in the cell

If we knew that these were all the same cell type, notice the variations that would lead us to believe that this was malignant.

We have anisocytosis, anisokaryosis, tough to see the cell margins, but this is an example of a cell population that has multiples features that fit the criteria of malignancy

Question 11

What is the process by which a cell becomes neoplastic? aka the Neoplastic Transformation

Answer 11

1. Cell becomes autonomous.
2. Not subject to normal growth controls
3. Free of normal structural and functional constraints.

Remember though, it may outgrow its blood supply.

Question 12

Biologically (and behaviorally), in what ways to hyperplastic cells differ from neoplastic cells?

Answer 12

Hyperplastic cells:

• Have a known cause
• Are uniform in appearance, have an increased cellular density
• Are potentially reversible
• Sometimes useful
• Don’t spread
• Not heritable

Neoplastic cells:

• Have an unknown cause
• Look out of place. Increased cellularity, inconsistent cell sizes/shapes
• Not reversible
• Never useful
• Can potentially spread. Local invastion to distant metastasis
• Can be heritable.