Tumours

Question 1

Describe the difference between benign and malignant tumours in:
Growth pattern
Growth rate
Cell division 
Nuclei 
Histology
Clinical effects
Treatment

Answer 1

Growth pattern:
B - cells expand but stay localised and don’t spread
M - can invade and metastasise to different sites

Growth rate:
B - slower
M - faster

Cell division:
B - normal
M - occurs numerously

Nuclei:
B - small, regular nuclei
M - larger, polymorphic (high DNA content) nuclei

Histology:
B - Well differentiated, resembles tissue of origin
M - poorly differentiated, does not resemble tissue of origin

Clinical effects:
B - local pressure on adjacent sites, bleeding
M - local pressure and metastasis to different areas

Treatment:
B - excision
M - excision and chemotherapy/radiotherapy

Question 2

What are the four ways of tumour transmission?

Answer 2

Local invasion of adjacent cells
Bloodstream
Lymphatic spread
Transcoelomic: across planes

Question 3

Define a tumour

Answer 3

An excessive, uncontrolled proliferation of cells due to a genetic mutation which is passed on from one tumour cell to its progeny.

Question 4

Define cell proliferation

Answer 4

Process which results in an increase in the number of cells

Question 5

Give three examples of what we need cell proliferation for

Answer 5

Embryogenesis: to form embryo
Normal tissue homeostasis
Wound healing and repair

Question 6

Define hyperplasia and give an example

Answer 6

Increase in the number of cells in a tissue or organ e.g. callous on hands or endometrium in preparation for receiving ovum

Question 7

Define hypertrophy and give an example

Answer 7

Increase in size of cell causing enlargement of tissue/organ

e.g. weightlifters - muscles get bigger

Question 8

How are tumours classified

Answer 8

Biological behaviour (benign or malignant)
Cell of origin

Question 9

Describe benign and malignant tumours

Answer 9

Benign tumours: stay localised to their site of origin

Malignant: are able to invade and metastasise

Question 10

What forms a barrier between benign tumours and hosts?

Answer 10

A fibrous connective tissue capsule which encapsulates the tumour

Question 11

Define dysplasia

Answer 11

abnormal growth/development of cells

Question 12

define metaplasia

Answer 12

change from one type of differentiated tissue to another

Question 13

What is a carcinoma

Answer 13

Tumour that is of epithelial origin

Question 14

What is a sarcoma

Answer 14

Tumour that is of connective tissue origin

Question 15

What is metaplasia a precursor to?

Answer 15

Dysplasia and neoplasia

Question 16

What is a teratoma and where does it originate from?

Answer 16

A teratoma is a germ cell tumour. It is made up of different tissue types e.g. bone, hair, teeth.

It originates from germ cells found in ovaries and testes