Cancer

Question 1

Define a tumour

Answer 1

Any kind of mass forming lesion.

May be neoplastic, hamartomatous or inflammatory (e.g. nasal polyps inflammatory lumps in nose).

Question 2

Define neoplasm

Answer 2

The autonomous growth of tissue which have escaped constraints on cell proliferation
Dysregulated growth

Question 3

What are the two broad descriptions that we have to describe neoplasms?

Answer 3

Benign - remain localised

Malignant - invade locally/spread to distant sites - this spread is called metastasis

Question 4

What kind of tumour is a cancer?

Answer 4

Malignant neoplasms

Question 5

What are the differences in appearance between benign and malignant neoplasms?

Answer 5

benign neoplasm- well contained, smooth round appearance

malignant neoplasm- not well demarcated margins, hard to describe where it starts and ends

Question 6

What are the 6 hallmark features of neoplastic cells (cancerous)?

Answer 6

Evading apoptosis 
Sustained angiogenesis 
limitless replicative potential
Insensitivity to anti-growth signals 
Tissue invasion and metastasis
Self-sufficiency in growth signals

Question 7

Define what is meant by a hamartoma

Answer 7

Tissue is found in the wrong place in an organ
Localised benign overgrowths of one or more mature cells types
ie overgrowth of cartilage tissue in lungs
represent architectural not cytological abnormalities

Question 8

Why are hamartomas more common in children?

Answer 8

usually caused by genetic abnormalities in important developmental genes.

Question 9

Define what is meant by heterotopia

Answer 9

Normal tissue being found in parts of the body where they are not usually present
ie pancreas tissue on intestinal wall

Question 10

Define what is meant by a teratoma

Answer 10

These are tumours derived from germ cells and can contain tissue derive from all three for 3 germ cell layers
They may contain mature and / or immature tissue and even cancers.
(The 3 germ layers are ectoderm, endoderm and mesoderm)

Question 11

What are the usual stems and suffixes used to describe neoplasms?

Answer 11

Stem = relevant tissue
Suffix
= oma if benign
= sarcoma if malignant

Question 12

What are exceptions to the normal rules for naming cancers?

Answer 12

All malignant neoplasms 
Hepatoma - liver
Melanoma - melanocytes 
Mesothelioma - pleural tissue  
Seminoma - germ cell neoplasm of testis 
Lymphoma - lymphocytes

Question 13

What is meant by invasion?

Answer 13

This means direct extension into the adjacent connective tissue and /or other structures e.g. blood vessels.
This is what distinguishes dysplasia/carcinoma in situ from cancer.

Question 14

Describe how invasion can be used to distinguish between benign and malignant neoplasms

Answer 14

Malignant tumours infiltrate and destroy the surrounding tissue, poorly demarcated
Invasion will often trigger an immune response- so we will see lymphocytes on histology

Most benign tumours grow as cohesive, expansile masses that remain localised to their site of origin (encapsulated)- don’t infiltrate surrounding tissue

Question 14

Describe how invasion can be used to distinguish between benign and malignant neoplasms

Answer 14

Malignant tumours infiltrate and destroy the surrounding tissue, poorly demarcated
Invasion will often trigger an immune response- so we will see lymphocytes on histology

Most benign tumours grow as cohesive, expansile masses that remain localised to their site of origin (encapsulated)- don’t infiltrate surrounding tissue

Question 15

Describe what is meant by metastasis

Answer 15

This means spread ,via blood vessels etc, to other parts of the body.
All malignant tumours have the capacity to metastasise
Formation of discontinuous tumour implants at a distance from the main tumour mass
Only gliomas and basal cell carcinomas cannot metastasise

Question 16

Where does a carcinoma cancer begin?

Answer 16

cancer that begins in the skin or in tissues that line or cover internal organs

Question 17

Where does a sarcoma cancer begin?

Answer 17

cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.

Question 18

Describe how metastasis can be used to distinguish between benign and malignant neoplasms

Answer 18

Benign neoplasms: Cannot metastasise

Malignant neoplasms: Can metastasise

Question 19

Describe what is meant by differentiation in cancer?

Answer 19

This means how much do the parenchymal cells of the tumour resemble the cells of the tissue it is derived from.

Parenchyma= functional cells

Well differentiated= looks like normal tissue
Poorly differentiated= looks nothing like normal tissue

Question 20

Describe how neoplastic cells can look different from normal cells

Answer 20

Large, variably shaped nuclei
Many dividing cells (disorganised)
Variation in size and shape
Loss of normal features

Question 21

Describe how differentiation can be used to distinguish between benign and malignant neoplasms

Answer 21

Benign: Often well differentiated
Malignant: Can show various levels of differentiation
Anaplastic= no differentiation at all (no specialized or functional features of cells seen)

Question 22

What are anaplastic cells?

Answer 22

A term used to describe cancer cells that divide rapidly and have little or no resemblance to normal cells.

Question 23

Describe what is meant by the growth pattern of the tumour

Answer 23

This means how much does the architecture of the tumour resembles the architecture of the tissue it is derived from.
Tumours have less well defined architecture than the tissue they are derived from.

Question 24

Describe how growth pattern can be used to distinguish between benign and malignant neoplasms

Answer 24

Benign neoplasms: Grow slowly and so retain normal tissue architecture more Malignant neoplasms: Grow rapidly and so lose normal tissue architecture.

Question 25

How does growth rate of a tumour affect differentiation?

Answer 25

Rate of growth correlates with the level of differentiation (faster they grow- the more they lose the normal architecture)

Question 26

What are the four ways to differentiate benign and malignant tumours?

Answer 26

Invasion Metastasis Degree of differentiation Growth pattern

Question 26

What are the four ways to differentiate benign and malignant tumours?

Answer 26

Invasion Metastasis Degree of differentiation Growth pattern

Question 27

What are the 5 ways tumours can spread?

Answer 27

``` Direct extension Haematogenous Lymphatic Transcoelomic Perineural ```

Question 28

Describe how tumours can spread by direct extension

Answer 28

This is associated with a stromal (stromal cells around tissue that support the tumour) response to the tumour. This includes fibroblastic proliferation (“ a desmoplastic response”), vascular proliferation (angiogenesis) and an immune response.

Question 29

Describe haematogenous spread of tumours

Answer 29

This is via blood vessels. The blood vessels usually invaded are the venules and capillaries because they have thinner walls. Most sarcomas metastasise first via the blood vessels.

Question 30

Describe lymphatic spread of tumours

Answer 30

This is via lymphatics to lymph nodes and beyond.The pattern of spread is dictated by the normal lymphatic drainage of the organ in question. Most epithelial cancers metastasise first via the lymphatics. 

Question 31

Describe the transcolemic spread of tumours

Answer 31

the spread of a malignancy into body cavities across the peritoneal cavity This is via seeding of body cavities. The commonest examples are the pleural cavities (for intrathoracic cancers) and the peritoneal cavities (for intra-abdominal cancers)  Direct seeding of body cavities and surfaces (peritoneal, pleural, pericardial, subarachnoid, joint)-

Question 31

Describe perineural spread of tumours

Answer 31

This is via nerves This is an underappreciated route of cancer spread Nerves have a space around them which tumours use

Question 32

Describe the 3 ways in which we can assess tumour spread

Answer 32

Clinically - how the patient is doing Radiologically - imaging of the tumour Pathologically - sampling of the tumour

Question 33

Describe how we grade a tumour

Answer 33

Based on degree of differentiation and on the number of mitoses 

Question 34

Name some grading systems for different cancers

Answer 34

Dukes’ – Colorectal FIGO – Ovarian Ann Arbor – Lymphoma Gleason – Prostate

Question 35

How do benign neoplasms become malignant neoplasms?

Answer 35

Will acquire more and more genetic mutations that enable it to invade the surrounding tissue and spread to other sites Difficult to find the ‘driver’ mutation that was responsible for the cancerous change

Question 36

What type of cancer is haematogenous common in?

Answer 36

Liver and lungs are most common site due to venous drainage  | Renal cell carcinoma can grow within renal vein to Inferior Vena Cava and into the right atrium.

Question 37

What causes nodal hyperplasia?

Answer 37

Nodes may contain the spread locally Evoke an immune response which causes nodal hyperplasia  Not every enlarged node in the region of a tumour contains metastatic spread

Question 38

How do we describe tumour spread using the TNM system?

Answer 38

This is known as staging: T = Tumour: the tumour size or extent of local invasion( T1-T4) N = Nodes: number of lymph nodes involved (1,2,3)  M = Metastases: presence of distant metastases (No,1,2)   This is called the “TNM" system and the details are different for each kind of cancer

Question 39

What is an example of a benign and malignant tumour of squamous epithelium?

Answer 39

``` Benign = squamous papilloma Malignant = squamous cell carcinoma ```

Question 40

What is an example of a benign and malignant tumour of glandular epithelium?

Answer 40

``` Benign = adenoma Malignant = adenocarcinoma ```

Question 41

What is an example of a benign and malignant tumour of transitional epithelium?

Answer 41

``` Benign = transitional papilloma Malignant = transitional cell carcinoma ```