Neoplasia

Question 1

What is Neoplasia?

Answer 1

an abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the normal tissues and persists in the same excessive manner after the cessation of the stimuli which has evoked the change

Question 2

What are the basic components of neoplasia?

Answer 2

Two basic components:

i) proliferating neoplastic cells (parenchyma)
ii) supporting tissue (stroma)

Question 3

What are mixed tumours

Answer 3

Divergent differentiation from single cell line:

Question 4

Tumors representing more than one germ layer: are called?

Answer 4

Teratoma

Question 5

What is ectopic rest/choristoma?

Question 6

Mass of disorganized, but mature specialized cells or tissue indigenous to that site

what is this called?

Answer 6

Hamartoma

Question 7

What is the biology of tumour growth

Answer 7

There are four phases:

i) Malignant change in the target cell (transformation)
ii) Growth of the transformed cells and they divide
iii) Local invasion into tissue
iv) Distant metastases

Question 8

one picture is a normal histology of a colon and the other is an adenocarcinoma of colon

which is which

Answer 8

top: adeno
bottom: normal

Question 9

What are the characterisitcs of tumour

Answer 9

Pleomorphism -varaiton in the sice and shape of the cell/ nuclei

hyperchromatism-more chromatin than normal

darker nuclei

increase in mitosis

loss of polarity

tumour necrosis

Question 10

What is dyslasia?

Answer 10

• disordered growth
• seen in epithelial lined structures (cervix)
• when entire thickness of the epithelium is involved: carcinoma in situ
• not always progresses to malignancy
• (mild to moderate dysplasia are reversible)

Question 11

What is the growth fraction

Answer 11

the proportion of cells within the tumor population that are in the proliferative pool

Question 12

rate of growth of tumour is then determined by?

Answer 12

excess of cell production over cell loss

Question 13

examples of high growth fraction s

Answer 13

leikemia, lymphomas, small cell carcionma of the lung

Question 14

examples of low growth fraction

Answer 14

carcinoma colon / carcinoma breast

Question 15

What is carciongenesis?

Answer 15

Carcinogenesis is the process which results in the transformation of a normal cell to a neoplastic cell by causing permanent genetic alterations

so basically causation of malignat tumour

Question 16

oncogensis:

Answer 16

causation of benign and malignant tumours

Question 17

carcinogen:

Answer 17

an agent known or suspected to participate in the causation of tumours

Question 18

meaning of epigenetics

Answer 18

 Heritable changes in the DNA which do not involve alterations in the DNA sequence.

 Covalent modification of the DNA itself or of the histones which package the DNA.

 Epigenetic alterations can be inherited or acquired. Epigenetic modulation is a key mechanism of the geneenvironment interaction.

 Many covalent modifications have been identified, but methylation is the most extensively studied.

Question 19

What is loss of is heterozygosity

Answer 19

one copy of a functional tumour suppressor gene is lost

Question 20

Primary vs Secondary Tumour

Answer 20

 A primary tumour is the first or original tumour which forms in the tissue of origin of the tumour.

 A secondary tumour forms as the result of the metastasis of a primary tumour to a location away from the primary tumour.

 Secondary tumours can be metastases to other sites within the same organ, or to other organs.

Question 21

is this primary or secondary tumour

Answer 21

primary

Question 22

Answer 22