Neoplasia

Question 1

What is a tumour?

Answer 1

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 a neoplasia?

Answer 2

It is basically a new growth, so is pretty much a tumour.

Question 3

Define hypertrophy?

Answer 3

Is an increase in the size of an organ due to an increase in the size of the constituent cells.
Eg. left ventricle of heart in hypertension.

Question 4

Define hyperplasia?

Answer 4

Is an increase in the size of an organ as a result of cell proliferation
Eg. uterus in pregnancy.

Question 5

Define dysplasia?

Answer 5

The prescence of cells of an abnormal type within a tissue, which may signify a stage preceeding the development of cancer.

Question 6

Define metaplasia?

Answer 6

A change from one type of differentiated tissue to another, often resulting tissue is better adpated to the environment, this can be a precursor of dysplasia and cancer.

Question 7

Define benign?

Answer 7

Tumours that stay localised at their site of origin.

Question 8

Define malignant?

Answer 8

Tumours able to invade and spread to different sites = cancer.

Question 9

How are tumours classified?

Answer 9

They are classified by:

• Biological behaviour; benign or malignant
• Cell of origin; -usually relates to cell/tissue type of origin = histogenesis
• Broad categories are connective tissue, epithelium, heamatopoetic/lymphoid, neural tissue.

Question 10

How are benign and malignant tumours distinguished?

Answer 10

Growth pattern; Benign= expansion, remains localised
Malignant= infiltrate locally, metastasise
Growth Rate;Benign= generally slow
Malignant= Faster
Mitosis; Benign= few, normal
Malignant= numerous, including atypical forms
Nuclei; Benign= small, regular, uniform
Malignant=larger, pleomorphic, increased DNA
content
Histology; Benign= resembles tissue of origin
Malignant= may differ from tissue of origin,
(less well differentiated).
Treatment; Benign= local excision
Malignant= local excision and perhaps
radiotherapy and/or chemotherapy

Question 11

In which ways can tumours spread?

Answer 11

• Local invasion
• Lymphatic spread (common for carcinomas)
• Blood Spread (common for sarcomas)
• Transcoelomic spread

Question 12

How are tumours named?

Answer 12

Epithelial: 
Benign- OMA
Malignant- CARCINOMA
Connective Tissue:
Benign- OMA
Malignant- SARCOMA
There are also exceptions to the rule.

Question 13

What is the difference between primary and secondary tumour sites?

Answer 13

Primary= refers to the original site of the tumour 
Secondary= refers to any additional sites where the cancer has spread.

Question 14

What are the clinical effects of benign cancers?

Answer 14

• presence of lump and /pain
• effects of pressure on adjacent tissue
• effects of substances produced by tumour

Question 15

What are the clinical effects of malignant cancers?

Answer 15

Local effects- palpable mass often with pain, tumour may ulcerate and bleed to cause anaemia, tumour may obstruct hollow organ.
Non-metastatic effects- loss of appetite, weight loss, generally unwell, anemia, fever
Paraneoplastic syndromes- due to innappropriate hormone secretion by tumour.

Question 16

What is the comparison of normal vs. cancer cells?

Answer 16

Nucleus= cancer cells have large variably shaped nuclei
No. of cells= many dividing cells, disorganized arrangement in cancer cells
Size= in cancer cells there is variation in size and shape
Features of cell= Cancer cells have loss of normal features (anaplasia)

Question 17

Why do Cancer cell become more basophillic?

Answer 17

They are more active due to more RNA’s and mRNA’s in the cytoplasm, this makes them appear bluer under the microscope.