Pathology of Cancer

Question 1

Define ‘neoplasm’.

Answer 1

A neoplasm is 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 2

-oma is the nomenclature for…?

Answer 2

Benign neoplasms

Question 3

What is a benign cartilaginous tumour named?

Answer 3

Chrondroma

Question 4

What is a fibroma?

Answer 4

Fibrous tumour (benign)

Question 5

What is a benign bone tumour named?

Answer 5

Osteoma

Question 6

What is an adenoma?

Answer 6

Tumour forming glands

Question 7

What is a benign tumour with finger-like projections named?

Answer 7

Papilloma

Question 8

What is a papillary cystadenoma?

Answer 8

Papillary and cystic tumor forming glands

Question 9

What is a polyp?

Answer 9

A tumour that projects above a mucosal surface

Question 10

What are sarcomas? Give three examples.

Answer 10

Mesenchymal tumours e.g. chondrosarcoma, fibrosarcoma, osteosarcoma

Question 11

What are carcinomas? Give three examples.

Answer 11

(Malignant) Epithelial tumours that can arise from ectoderm, mesoderm or endoderm, e.g. adenocarcinoma, squamous cell carcinoma, undifferentiated carcinoma

Question 12

What is an adenocarcinma?

Answer 12

Gland forming tumour (malignant)

Question 13

What is a squamous cell carcinoma?

Answer 13

Squamous differentiation (malignant)

Question 14

What is a malignant cartilaginous tumour called?

Answer 14

Chrondrosarcoma

Question 15

What is a malignant fibrous tumour called?

Answer 15

Fibrosarcoma

Question 16

What is an osteosarcoma?

Answer 16

Malignant bone tumour

Question 17

What is meant by a well differentiated neoplasm?

Answer 17

Resembles mature cells of tissue of origin and correlated with biologic behaviour
E.g. with benign tumours

Question 18

What is meant by a poorly differentiated neoplasm?

Answer 18

Composed of primitive cells with little differentiation - usually have a worse prognosis (and are malignant)

Question 19

What is an anaplastic tumour?

Answer 19

Undifferentiated

Question 20

What cells is a leiomyoma from? Is it benign or malignant?

Answer 20

Smooth muscle cells

Benign

Question 21

What is a keratin pearl? When is it seen?

Answer 21

A hallmark of well differentiated squamous cell carcinoma is that the nests of invading cells still attempt to make keratin which then gets deposited in the centre of the nests, resulting in a keratin “pearl”.

Question 22

What are two characteristics of well differentiated squamous cell carcinomas?

Answer 22

Still make visible intercellular bridges

Keratin pearls

Question 23

Name two tumours with mixed differentiation.

Answer 23

Pleomorphic adenoma of salivary gland

Carcinosarcoma

Question 24

What is a teratoma?

What is the most common one?

Answer 24

Tumour comprised of cells from more than one germ layer. They arise from totipotent cells (usually gonads). The most common one is benign cystic teratoma of ovary.

Question 25

Aberrant differentiation (not true neoplasms) - give two examples.

Answer 25

Hamartoma (disorganized mass of tissue whose cell types are indigenous to the site of the lesion) Choriostoma (ectopic focus of normal tissue/heterotopia)

Question 26

What is meant by 'misnomer'?

Answer 26

From nomenclature you would think they are benign, but they are infact malignant.

Question 27

What is a hepatoma?

Answer 27

Malignant liver tumour

Question 28

What are... Melanoma? Seminoma? Lymphoma?

Answer 28

Malignant skin tumour Malignant testicular tumour Malignant tumour of lymphocytes

Question 29

State the four stages of the natural history of malignant tumours.

Answer 29

Malignant change in the target cell (transformation/carcinogenesis) Growth of the transformed cells Local invasion Distant metastases

Question 30

What are the features of anaplasia? (7)

Answer 30

1. Pleomorphism – size, shape, abnormal nuclear morphology 2. Hyperchromasia 3. High nuclear cytoplasmic ratio 4. Chromatin clumping 5. Prominent nucleoli 6. Mitoses - mitotic rate, location of mitoses 7. Loss of polarity

Question 31

What does dysplasia mean?

Answer 31

Abnormal growth, with some but not all of the features of malignancy present. It may develop into malignancy e.g. with uterine cervix, or colon polyps. It is graded as low-grade or high-grade.

Question 32

What influences the tumour growth rate? (3)

Answer 32

Doubling time of tumour cells Fraction of tumour cells in replicative pool (tumour stem cells, may only be 20% even in rapidly growing tumours) Rate at which tumour cells are shed or lost by apoptosis or maturation

Question 33

``` The doubling time of tumour cells ________ as tumour grows. 30 doublings (10 to the nine cells) = how many grams? How many grams is a lethal burden? ```

Answer 33

Lengthens 1g (smallest clinically detectable mass) 1kg

Question 34

Explain tumour growth and the proliferative/non-proliferative pool.

Answer 34

There area two major pools – the proliferative and the non-proliferative pools. Some of the transformed cells die, some may become quiescent (G0) and some differentiate. This adds to the non-proliferative pool.

Question 35

Compare the rate of growth of benign vs malignant tumours.

Answer 35

Benign - progressive but slow. Mitoses few and normal. | Malignant - variable. Mitoses more frequent and may be abnormal.

Question 36

Compare the differentiation of benign vs malignant tumours.

Answer 36

Benign – well differentiated. | Malignant – some degree of anaplasia.

Question 37

Compare the local invasion of benign vs malignant tumours.

Answer 37

Benign – cohesive growth. Capsule and basement membrane not breached. Malignant – poorly cohesive and infiltrative.

Question 38

Compare the metastasis of benign vs malignant tumours.

Answer 38

Benign – absent | Malignant – may occur

Question 39

Metastasis is an unequivocal sign of __________. There is seeding of body cavities. It may be ________ or _________.

Answer 39

Malignancy Lymphatic Haematogenous

Question 40

Why is nodal metastasis significant?

Answer 40

Prognostic – number of involved nodes is an important component of the TNM staging system Therapeutic – adjuvant chemotherapy to reduce the incidence of recurrence and metastasis. The risk of recurrence is determined by the extent of nodal involvement and the histologic grade.

Question 41

Give three examples of tumour-host interactions.

Answer 41

Local invasion Distant metastasis Paraneoplastic syndrome

Question 42

What is paraneoplastic syndrome?

Answer 42

Clinical syndromes involving non-metastatic systemic effects that accompany malignant disease

Question 43

What is paraneoplastic syndrome mediated through? (4)

Answer 43

Cross-reacting antibodies Production of physiologically active factors Interference with normal metabolic pathways Idiopathic

Question 44

How are paraneoplastic syndromes classified? (4)

Answer 44

Endocrine Neurological Mucocutaneous Haematological

Question 45

Give examples of endocrine paraneoplastic syndromes.

Answer 45

Hormone secreting tumours - Cushing's, hyper/hypoglycaemia

Question 46

Give an example of a neurological paraneoplastic syndrome.

Answer 46

Immune mediated - Lambert-Eaton myastenic syndrome

Question 47

Give two examples of mucocutaneous paraneoplastic syndromes.

Answer 47

Acanthosis nigricans | Dermatomyositis

Question 48

Give an example of a haematological paraneoplastic syndrome.

Answer 48

Granulocytosis