Characteristics of Tumours

Question 1

What is a tumour?

Answer 1

A swelling or a mass of any kind

Question 2

What is neoplasia?

Answer 2

New, uncontrolled growth of cells that is not under physiologic control. Can be benign or malignant.

Question 3

What is cancer?

Answer 3

A generic term for a large group of diseases characterized by the growth of abnormal cells beyond their usual boundaries that can then invade adjoining parts of the body and/or spread to other organs.

Question 4

Hallmarks of cancer

Answer 4

1. Environmental factors causing mutations + inherited genetic mutations
2. Mutations accumulate
3. Hallmarks of cancer accumulate
4. Malignant cell

Question 5

What sets cancer apart from benign neoplasms?

Answer 5

The invasion/spread to other organs

Question 6

What is embryological histogenesis?

Answer 6

The formation of differentiated tissues from undifferentiated endoderm, ectoderm and mesoderm cells.

Question 7

What is tumour histogenesis?

Answer 7

Tumours are named according to the tissues from which they arise

Question 8

What are tumours arising from the endoderm (internal layer) called? E.g. tumour arising from the epithelial lining of digestive tract?

Answer 8

Carcinoma (either squamous cell carcinoma or adenocarcinoma)

Question 9

What are tumours arising from the mesoderm (middle layer) called? E.g. skeletal muscle cell?

Answer 9

Sarcoma –> e.g. leiomyosarcoma is a rare type of cancer that affects smooth muscle tissue

Question 10

What are tumours arising the ectoderm (outer layer) called? E.g. from pigment cells?

Answer 10

Melanoma

Question 11

What is differentiation?

Answer 11

the extent to which a neoplasm resembles its tissue of origin:

• Well-differentiated = neoplasm closely resembles tissue of origin
• Moderately-differentiated= neoplasm shows some resemblance to tissue of origin
• Poorly-differentiated= neoplasm does not resemble tissue of origin

Question 12

What is anaplasia?

Answer 12

A neoplasm that is poorly differentiated and highly pleomorphic

Question 13

What is pleomorphic?

Answer 13

Having variation in the size and shape of cells or their nuclei.

Question 14

Most common cancers in females

Answer 14

Question 15

Why are non-melanoma skin cancers typically excluded from data?

Answer 15

Although they carry a high incidence, their mortality risk is low (squamous cell carcinoma and basal cell carcinoma)

Question 16

Female deaths from cancer

Answer 16

Question 17

Most commoon cancers in males?

Answer 17

Question 18

Male deaths from cancer?

Answer 18

Question 19

Invasion: benign vs malignant?

Answer 19

Benign: Neoplasm does NOT invade surrounding tissues

Malignant: Neoplasm DOES invade surrounding tissues

Question 20

Mets; benign vs malignant?

Answer 20

Benign: do not metastasise

Malignant: may metastasise; lymphatic, haematogenous, direct seeding

Question 21

What is metastasis?

Answer 21

The development of secondary malignant growths at a distance from a primary site of cancer.

Question 22

What is often the first site of metastasis?

Answer 22

Lymph nodes

Question 23

What is direct seeding?

Answer 23

Malignant neoplasm penetrates into a natural body cavities

Question 24

Rate of growth; benign vs malignant?

Answer 24

Benign: slow rate of growth

Malignant: fast rate of growth (division exceeds cell death)

Question 25

Differentiation; benign vs malignant?

Answer 25

Benign: well differentiated

Malignant: can be well differentiated, moderately or poorly differentiated or even anaplastic

Question 26

Prognosis; benign vs malignant?

Answer 26

Benign; rarely fatal (unless CNS as can lead to compression of brain tissue)

Malignant: often fatal

Question 27

What are the 3 main categories of tumour complications?

Answer 27

1. Effects of primary tumour
2. Effects of distant metastases
3. Paraneoplasic syndromes

Question 28

What are the main effects of a primary tumour?

Answer 28

• Invasion into and replacement of normal tissues/organs –> failure of that organ to function (e.g. bone marrow, liver)
• Pressure on normal tissue –> failure of that organ to function (especially in brain)
• Invasion into blood vessels –> bleeding
• Pressure on the blood vessels –> ischaemia
• Pressure/invasion into nerves –> loss of nerve function/pain
• Grow into a lumen –> obstruction (e.g. colon)

Question 29

What are distant metastases?

Answer 29

When a cancer spreads to different parts of the body forming new (secondary) tumours.

Question 30

What are the effects of distant metastases?

Answer 30

• Invasion into tissues
• Pressure on tissues
• Invasion into blood vessels etc

Question 31

What are paraneoplastic syndromes?

Answer 31

Signs and symptoms that are NOT related to local effects of the primary or metastatic tumours

Question 32

What do paraneoplastic syndromes develop as a result of?

Answer 32

• Proteins/ hormones secreted by tumour cells
• Immune cross reactivity between tumour cells and normal tissues

Question 33

What is a stroma?

Answer 33

• Cells that support the parenchyma
• Organ = parenchyma + stroma

Question 34

What is parenchyma?

Answer 34

Cells that perform actual function of an organ eg cells that do gas exchange (pneumocytes) in the lungs, cells that contract in the heart (myocytes)

Question 35

Stroma contain many cell types including…?

Answer 35

• Blood vessels
• Fibroblasts (+ the collagen they make)
• Immune cells

Question 36

What is desmoplasia?

Answer 36

Desmoplasia refers to growth of dense connective tissue or stroma

Question 37

What cells are found in tumour stroma?

Answer 37

Tumour stroma composed of the same cells types as normal stroma, but the stromal cells have different functions; blood vessels, fibroblasts, immune cells

Question 38

With this colonic tumour, what local effect is the patient at most risk of developing?

Answer 38

Bowel obstruction

Question 39

Which arrow is pointing to tumour stroma?

Answer 39

2

• 3 is normal colonic epithelium and the gaps in between is normal stroma

Question 40

What is the grade of a tumour?

Answer 40

How well/poorly it is differentiated