Tumour Classification

Question 1

What is a tumour?

Answer 1

A tumour is formed by an excessive, uncontrolled proliferation of cells as a result of an irreversible genetic change which is passed from one tumour cell to its progeny.

Question 2

What is the difference between benign and malignant tumours?

Answer 2

Benign tumours stay localised at their site of origin.

Malignant tumours are able to invade and spread to different sites.

Question 3

What is the difference in the growth rate between benign and malignant tumours?

Answer 3

Malignant tumours tend to grow faster.

Question 4

What is the difference between the nuclei of benign and malignant tumours?

Answer 4

Benign tumours have small, regular, uniform nuclei.

Malignant tumours have larger, pleomorphic nuclei with increased DNA content.

Question 5

What is the nomenclature for benign and malignant epithelial tumours?

Answer 5

Benign -OMA

Malignant -CARCINOMA

Question 6

What is the nomenclature for benign and malignant connective tissue tumours?

Answer 6

Benign -OMA

Malignant -SARCOMA

Question 7

What is the usual initial mode of spread for carcinomas?

Answer 7

Breast, colon, lung.

Question 8

What is the usual initial mode of spread for sarcomas?

Answer 8

Blood

Question 9

What are the common site of metastasis relating to each primary origin?: Lung, Liver, Bone.

Answer 9

Lung: sarcoma and renal carcinoma
Liver: colon carcinoma
Bone: prostatic carcinoma and others.

Question 10

What are the effects of a benign tumour?

Answer 10

Lump +/- pain
Pressure on adjacent tissue.
Effects of substances produced by tumour, e.g. hormones

Question 11

What are the effects of malignant tumours?

Answer 11

Local effects
Metastatic effects
Non-metastatic effects
Paraneoplastic syndromes

Question 12

What are the local effects of malignant tumours?

Answer 12

Palpable mass, often with pain.
Tumour may ulcerate and bleed, causing anaemia.
Tumour may obstruct hollow organ, e.g. bowel

Question 13

What are the non-metastatic effects of tumours?

Answer 13

Loss of appetite, weight loss and wasting.
Generally unwell
Anaemia
Fever
Related to ctokines eg. IL1 and TNF

Question 14

What causes paraneoplastic syndromes?

Answer 14

Inappropriate hormone secretion.

Question 15

Describe Dukes’ staging of colorectal cancer.

Answer 15

A - tumour confined to bowel wall - 85-95% 5yr survival.
B - Tumour spread through muscularis propria - 60-80% 5yr survival
C - Local nodes involved - 30-60% 5yr survival.
D - Distant metastases -

Question 16

What is the function of myc?

Answer 16

Nuclear transcription factor.

Question 17

What does high expression of myc do?

Answer 17

Accelerates cell growth.

Question 18

What happens to Rb through the cell cycle?

Answer 18

It is increasingly phosphorylated.

Question 19

What are the oncogenes in an adenovirus?

Answer 19

E1A and E1B

Question 20

Name two major viral targets.

Answer 20

P53

Rb(p105)