Disorder of growth, differentiation and tumour

Question 1

What is growth

Answer 1

Growth is the process of increase in size resulting from the synthesis of specific tissue components

Question 2

What is differentiation

Answer 2

• A process whereby a cell develops an overt specialised function or morphology which distinguishes it from its parent cells

Question 3

What is Tumour differentiation

Answer 3

• refers to the extent to which neoplastic cells resemble comparable normal cells, both morphologically and functionally

Question 4

What is Anaplasia

Answer 4

• Lack of differentiation is called anaplasia

Question 5

What is Anaplasia a hallmark for

Answer 5

A hallmark of malignant transformation

Question 6

What does Anaplasia mean

Answer 6

• Means “to form backward” implying a reversion from a high level of differentiation to a lower level

Question 7

Name the morphological changes of anaplasia

Answer 7

• Pleomorphism
• Abundance of DNA
• Mitoses
• Loss of polarity
• Other changes: Formation of tumour giant cells

Question 8

What is Pleomorphism like in morphological changes of anaplasia

Answer 8

• Variation in size and shape

Question 9

What is Abundance of DNA like in morphological changes of anaplasia

Answer 9

• Nuclei are disproportionately large for the cell

Question 10

What is Mitoses like in morphological changes of anaplasia

Answer 10

• Mitosis does not necessarily indicate that a tumour is malignant or that the tissue is neoplastic

Question 11

What is Loss of polarity like in morphological changes of anaplasia

Answer 11

• The orientation of cells is markedly disturbed

Question 12

What is Neoplasia?

Answer 12

• 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 cessation of the stimuli which evoked the change

Question 13

What does Neoplasia mean

Answer 13

• Means the process of “new growth” and new growth is called a neoplasm

Question 14

What are the different types of tumours (neoplasm)

Answer 14

• Benign or Malignant

Question 15

What is malignant tumours also known as

Answer 15

• cancer

Question 16

What is the Behavioural classification of tumours

Answer 16

• Benign or malignant

Question 17

What is the Histogenetic classification of tumours

Answer 17

• cell of origin

Question 18

What is the nomenclature of tumours

Answer 18

• All have the suffix ‘-oma’
• Benign epithelial tumours are either papilloma’s or adenomas
• Benign connective tissue tumours have a prefix denoting the cell of origin
• Malignant epithelial tumours are carcinomas
• Malignant connective tissue tumours are sarcomas

Question 19

What are the characteristics of Benign tumours

Answer 19

• Non-invasive and remain localised
• Slow growth rate
• Close histological resemblance to parent tissue
• A fibrous capsule to separate tumour from the host tissue, readily palpable and early moveable surgically

Question 20

What are the characteristics of Malignant tumours

Answer 20

• Invasive and capable of spreading directly or by metastasis
• Relatively rapid growth rate
• Variable histological resemblance to the parent tissue

Question 21

Compare the growth rate of Benign and Malignant tumours

Answer 21

Benign - slow
Malignant - relatively rapid

Question 22

Compare the Mitotic activity of Benign and Malignant tumours

Answer 22

Benign - Low
Malignant - High

Question 23

Compare the Histological feature (to original tissue) of Benign and Malignant tumours

Answer 23

Benign - Good
Malignant - Often poor

Question 24

Compare the Invasion of Benign and Malignant tumours

Answer 24

Benign - No
Malignant - Yes

Question 25

Compare the Metastases of Benign and Malignant tumours

Answer 25

Benign - Never Malignant - Frequent

Question 26

Compare the Border of Benign and Malignant tumours

Answer 26

Benign - circumscribed or encapsulated Malignant - poorly defined or irregular

Question 27

Compare Necrosis of Benign and Malignant tumours

Answer 27

Benign - Rare Malignant - Common

Question 28

What is Metaplasia

Answer 28

- A reversible change in which one adult cell type (epithelial or mesenchymal) is replaced by another adult cell type - May represent an adaptive substitution of cells that are sensitive to stress by cell types better able to withstand the adverse environment

Question 29

What is Metaplasia often association with

Answer 29

- Often in association with tissue damage, repair and regeneration

Question 30

What happens if influence that are predispose to metaplasia is persistent

Answer 30

- May initiate malignant transformation in metaplastic epithelium

Question 31

What does the term Dysplasia mean

Answer 31

- A term that literally means disordered growth

Question 32

Where is Dysplasia encountered

Answer 32

- Is encountered principally in metaplastic epithelia

Question 33

Dysplastic lesions are often what?

Answer 33

pre-neoplastic

Question 34

What is the architecture like for Dysplasia

Answer 34

- The architecture of the tissue may be disordered

Question 35

Does dysplasia progress to cancer

Answer 35

- Dysplasia does not necessarily progress to cancer

Question 36

What is the characteristics of Dysplasia

Answer 36

- Loss in the uniformity - of the individual cells and in their architectural orientation - Exhibit considerable pleomorphism and often contain hyperchromatic nuclei that are abnormally large for the size of the cell - Mitotic figures: abundant and appear in abnormal locations within the epithelium (not confined to the basal layers)

Question 37

What is Metastasis

Answer 37

- Metastases are tumour implants discontinuous with the primary tumour (only for malignant tumours)

Question 38

How does metastasis mark a tumour as malignant

Answer 38

- Because benign neoplasia do not metastasize

Question 39

Metastatic spread strongly reducing the possibility of what?

Answer 39

- a cure - Methods to block metastases would be of great benefit to patients

Question 40

What pathways of spread does Metastasis go

Answer 40

Pathways of spread: - DIRECT SEEDING of body cavities or surfaces: pleural, pericardial and peritoneal cavities - LYMPHATIC SPREAD: secondary tumours in the regional lymph nodes - HAEMATOGENOUS SPREAD (by the blood stream): secondary tumours in organs perfused by blood from a tumour - IMPLANTATION (after operation) : Rare

Question 41

What is carcinogenesis

Answer 41

- Non lethal genetic damage is the basis carcinogenesis - Carcinogenesis is a multi-step process at both the phenotypic and genetic levels

Question 42

How is a tumour formed by carcinogenesis

Answer 42

- A tumour is formed by the clonal expansion of a single precursor cell that incurred genetic damage

Question 43

What are the 4 classes of regulatory genes that are the principal targets of genetic damage

Answer 43

- The growth promoting oncogenes - The growth inhibiting tumour suppressor genes - Genes that regulate and programmed cell death (apoptosis) - Genes involved in DNA repair