1. Cellular Pathology of Cancer

Question 1

Define Metaplasia.

Answer 1

A reversible change in which one adult cell type (usually epithelial) is replaced by another adult cell type.

Question 2

Describe Barrett’s Oesophagus. What type of metaplasia is this?

Answer 2

When gastro-oesophageal reflux causes the oesophageal epithelium to change from squamous to columnar.

This is pathological metaplasia.

Question 3

Describe metaplasia in pregnancy.

Answer 3

In pregnancy, the cervix opens up and the columnar epithelium of the endocervical canal is exposed to the acidic uterine fluids making it become squamous

When the cervix closes up again, the cell types changes back to normal (hence why metaplasia is a REVERSIBLE change)

This is physiological metaplasia.

Question 4

Define Dysplasia.

Answer 4

An abnormal pattern of growth in which some of the cellular and architectural features of malignancy are present.

The cells in dysplasia are on the road to cancer but haven’t reached it yet

Dysplasia is a pre-invasive stage with and intact basement membrane

Question 5

What happens to the cells in dysplasia?

Answer 5

• There is a loss of architectural orientation
• There is a loss of uniformity of individual cells
• Nuclei are hyperchromatic and enlarged
• Mitotic figures are abundant, abnormal and in places where they aren’t usually found

Question 6

What are common site of dysplasia? What are their causes?

Answer 6

• Cervix - HPV infection
• Bronchus - smoking
• Colon - ulcerative collitis
• Larynx - smoking
• Stomach - pernicious anaemia
• Oesophagus - acid reflux

Question 7

Explain the picture.

Answer 7

This is a cervical biopsy

On the left you can see that the cells are very compact at the bottom then become more and more spaced out towards the lumen - normal cellular maturation

On the right hand side of this image, the cells are NOTundergoing normal maturation

There are compact cells with dark, dense nuclei on the surface - these cells are normally seen further down

Question 8

Describe what is meant by low and high grade dysplasia.

Answer 8

Low Grade - low risk of progression to cancer and more likely to be reversible

High Grade - high risk of progression to cancer and less likely to be reversible

Difference between low grade and high grade: both show changes of dysplasia, but the changes are more severe in high grade dysplasia

The nuclei are bigger and the nucleo-cytoplasmic ratio is higher in high grade dysplasia

Question 9

Define Neoplasia.

Answer 9

Any new growth, benign or malignant.

Question 10

Define malignancy.

Answer 10

An abnormal, autonomous proliferation of cells, unresponsive to normal growth control mechanisms

Question 11

Name characteristics of benign tumours.

Answer 11

1. DO NOT INVADE and DO NOT METASTASISE
2. Encapsulated - fibrous
   
   • They have a compressed capsule around them
   • Exception: fibroids (leiomyoma) in the uterus does NOT have a capsule
3. Usually well differentiated
   
   • They look like the tissues they come from
4. Slowly growing
5. Normal mitoses.

Question 12

When can benign tumours be fatal?

Answer 12

• Are in a dangerous location - e.g. meninges, pituitary
• Secrete something dangerous - e.g. insulinoma
• Gets infected - e.g. bladder (whenever you block anything that drains fluid, you will create the conditions for infection)
• Bleeds - e.g. stomach
• Ruptures - e.g. liver adenoma (can cause massive haemoperitoneum)
• Torts (twisted) - e.g. ovarian cyst

Question 13

Describe characteristics of malignant tumours.

Answer 13

1. Invade surrounding tissues
2. Spread to distant sites
3. No capsule
4. Well to poorly differentiated
5. Rapidly growing
6. Abnormal mitoses

Question 14

Define metastasis.

Answer 14

A discontinuous growing colony of tumour cells at some distance from the primary cancer.

Question 15

What does the site of metastasis depend on?

Answer 15

• The site of metastasis depends on the lymphatic and vascular drainage of the primary site
• Example: The pancreas is drained by the splenic vein, which then goes via the hepatic portal vein to the liver so pancreatic carcinomas tend to be present with liver metastases
• Lymph node involvement has a worse prognosis

Question 16

Define papilloma.

Answer 16

A benign epithelial tumour of surface epithelium. E.g. skin, bladder

Question 17

Define adenoma.

Answer 17

A benign epithelial tumour of glandular epithelium. E.g. stomach, thyroid, colon, kidney, pituitary, pancreas.

Question 18

Define carcinoma.

Answer 18

A malignant tumour derived from epithelium

Question 19

Name types of carcinomas.

Answer 19

• Squamous cell carcinoma
• Adenocarcinoma (adenoma that has become malignant)
• Transitional cell carcinoma (transitional epithilium is found in the bladder)
• Basal cell carcinoma

Question 20

What are benign soft tissue tumours of:

• bone
• fat
• smooth muscle

Answer 20

• Bone = osteoma
• Fat = Lipoma
• Smooth Muscle = Leiomyoma

Question 21

Define sarcoma.

Answer 21

A malignant tumour derived from connective tissue (mesenchymal) cells

Question 22

What are sarcomas of the:

• fat
• bone
• cartilage
• striated muscle
• smooth muscle
• nerve sheath

called?

Answer 22

The prefix is the site of the tumour e.g. osteosarcoma (bone)

• Fat = liposarcoma
• Bone = osteosarcoma
• Cartilage = chondrosarcoma
• Striated muscle = rhabdomyosarcoma
• Smooth muscle = leiomyosarcoma
• Nerve sheath = Malignant Peripheral Nerve Sheath Tumour

Question 23

Define Leukaemia.

Answer 23

Malignant tumour of bone marrow derived cells which circulate in the blood.

Question 24

Define Lymphoma.

Answer 24

Malignant tumour of lymphocytes (usually) in lymph nodes - tissue based lesion.

NOTE: lymphocytes are produced by the bone marrow and the are found in lymph nodes so in some cases you can get a mix of both lymphoma and leukaemia

Question 25

Define teratoma.

Answer 25

A tumour derived from germ cells which has the potential to develop into tumours of ALL THREE germ cell layers.

Three layers:

• Ectoderm
• Mesoderm
• Endoderm

Question 26

Whats the difference between gonadal teratomas in men and women?

Answer 26

• Gonadal teratomas in males are almost ALL MALIGNANT
• Gonadal teratomas in females are MOSTLY BENIGN

Question 27

Define Hamartoma.

Answer 27

Localised overgrowth of cells and tissue NATIVE TO THE ORGAN.

In other words: the tissues that are present are appropriate for that particular part of the body but the way that they are architecturally arranged is inappropriate

The cells are mature but architecturally abnormal

This is common in children, and should stop growing when they stop growing

Question 28

Describe the picture.

Answer 28

• This is a section of the liver showing bile ducts
• A normal portal tract only contains ONE bile duct
• Here there are loads of bile ducts
• Normal bile ducts are round but these ones are a little misshapen
• Though there are no issues cytologically
• These bile ducts are abnormally arranged

Question 29

How are tumours differentiated?

Answer 29

• Tumours are graded (how well differentiated they are) and staged (how far they’ve spread)
• Staging is more important
• High grade tumours generally have a high stage
• If you find a tumour you need to find out whether it is a primary tumour or if it is a secondary - this can be done by inspecting the tumour histologically and looking for evidence of normal function still present. E.g.
  
  • keratin is made by squamous cells
  • bile is made by hepatocytes
  • hormones e.g. insulin is made by the pancreas

Question 30

Define anaplastic tumours.

Answer 30

Tumours that show little or no differentiation.

Question 31

What is the specific grading systems for:

• breast cancer
• prostate cancer

Answer 31

Breast - Nottingham scoring system

Prostate - Gleason classification