1. Cellular pathology of cancer

Question 1

What is metaplasia?

Answer 1

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

Question 2

What changes occur in gastric metaplasia?

Answer 2

Stratified squamous to simple columnar

Question 3

What cells appear in intestinal metaplasia?

Answer 3

Goblet cells

Question 4

What is pathological metaplasia and give an example

Answer 4

• Reversible, benign change due to chronic physical or chemical irritation

• Barrett’s oesophagus
- gastro-oesophageal reflux causes the oesophageal epithelium to change from squamous to columnar

Question 5

What is physiological metaplasia and give an example?

Answer 5

• Reversible, benign change due to the surrounding environment

• Endocervical canal exposed to acidic uterine fluids during pregnancy, as the cervix opens up
• Columnar => squamous epithelium
• Changes back to normal when cervix closes up

Question 6

What is dysplasia?

Answer 6

• Pre-invasive stage of cancer development, with intact basement membrane
• Abnormal pattern of growth in which some cellular and architectural features of malignancy are present

Question 7

How does the nucleo-cytoplasmic ratio change in dysplasia?

Answer 7

• Increased

* Cell size is normal, but too much nucleus

Question 8

Describe the nuclei and mitotic figures in dysplasia

Answer 8

• Hyperchromatic and enlarged nuclei

* Abundant and abnormal mitotic figures, in places they shouldn’t be

Question 9

Where is dysplasia common and what causes it in these places?

Answer 9

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

Question 10

How does smoking change the bronchus epithelium?

Answer 10

Pseudostratified columnar => squamous - dysplasia => cancer

Question 11

In a cervical biopsy how can you tell if the cells are normal or potentially cancerous?

Answer 11

• Normally compact at the bottom and more spaced out towards the lumen - normal cellular maturation
• Abnormal cells don’t undergo normal maturation, so you get compact cells with dark, dense nuclei on the surface

Question 12

What is low and high grade dysplasia?

Answer 12

• Low - unlikely to go onto cancer, more likely to be reversible
• High - more severe: darker, higher nucleo-cytoplasmic ratio, less likely to be reversible

Question 13

What is malignancy?

Answer 13

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

Question 14

What is a neoplasia?

Answer 14

Any new growth, benign or malignant

Question 15

What is a tumour?

Answer 15

A swelling, generally without inflammation, caused by abnormal growth of a tissue e.g. nasal polyps

Question 16

How are benign tumours different from malignant tumours?

Answer 16

• Do not metastasise
• Encapsulated (still can invade the basement membrane)
• Usually well differentiated
• Slow growing
• Normal mitoses

Question 17

When can benign tumours be fatal?

Answer 17

Growing in a dangerous place
• Meninges => epilepsy
• Pituitary => secrete hormones
• Lateral ventricles => increased intracranial pressure
• Insulinoma => hypoglycaemic episodes
• Gets infected e.g. in bladder
• Bleeds e.g. stomach tumours
• Ruptures e.g. liver adenoma => haemoperitoneum
• Torts (twists) e.g. ovarian cyst => infarction

Question 18

How are malignant tumours different to benign tumours?

Answer 18

• Invade surrounding tissues
• Spread to distant sites
• Have no capsule
• Well to poorly differentiated - hard to determine where it originated
• Rapidly growing
• Abnormal mitoses

Question 19

What is a metastasis?

Answer 19

Discontinuous growing colony of tumour cells, at some distance from the primary cancer (can break off and embolise around the body)

Question 20

Where else is a pancreatic carcinoma likely to cause metastasis?

Answer 20

• Liver

* Pancreas drained by the splenic vein => hepatic portal vein -> lover

Question 21

Outline how colon cancer survival changes when lymph nodes are involved?

Answer 21

Dukes staging system
• Dukes A - confined to bowel wall (90% survival)
• Dukes C - lymph node involvement (30% survival)

Question 22

What type of tumour is a carcinoma?

Answer 22

Malignant epithelial tumour

Question 23

What type of tumour is a sarcoma?

Answer 23

Malignant tumour arising from cells of mesenchymal (connective tissue) origin - soft tissue tumour

Question 24

What is a papilloma and adenoma?

Answer 24

Types of benign epithelial tumours
• Papilloma - surface epithelium e.g. skin, bladder
• Adenoma - glandular epithelium e.g. stomach, thyroid

Question 25

Give 4 examples of different carcinomas?

Answer 25

1) Squamous cell carcinoma - from skin/oesophagus 2) Adenocarcinoma - from glandular epithelium 3) Transitional cell carcinoma - from transitional epithelium (stratified epithelium where the surface cells change shape when stretched) e.g. bladder) 4) Basal cell carcinoma

Question 26

Give 5 examples of benign soft tissue tumours?

Answer 26

1) Osteoma - bone 2) Chondroma - cartilage 3) Lipoma - fat 4) Leiomyoma - smooth muscle 5) Rhabdomyoma - striated muscle

Question 27

Give 6 examples of sarcomas?

Answer 27

1) Liposarcoma - fat 2) Osteosarcoma - bone 3) Chondrosarcoma - cartilage 4) Leiomyosarcoma - smooth muscle 5) Rhabdomyosarcoma - striated muscle 6) Malignant peripheral nerve sheath tumour

Question 28

What is the difference between leukaemia and lymphoma?

Answer 28

* Leukaemia - malignant tumour of bone marrow derived cells which circulate in blood * Lymphoma - malignant tumour of lymphocytes, in lymph nodes or spleen Lymphocytes produce in bone marrow and found in lymph nodes, so can get a mix of both types

Question 29

What is a teratoma and how are they different in males and females?

Answer 29

• Tumour derived from germ cells • Have the potential to develop into tumours of all 3 germ cell layers: - Ectoderm - Mesoderm - Endoderm • Gonadal teratomas are almost always malignant in males • Gonadal teratomas are almost always benign in females (contain hair and teeth)

Question 30

What is a hamartoma?

Answer 30

* Localised overgrowth of cells and tissues native to the organ * Cells are mature but architecturally abnormal - no cytological issue * Common in children, and should stop growing when they stop growing * Most are benign, but there is a risk of malignancy e.g. bile duct hamartomas (lots of bile ducts instead of one) , bronchial hamartomas

Question 31

``` How can you look for evidence of normal function for the following cells: • squamous cells • glandular epithelium • hepatocytes • pancreas ```

Answer 31

* Squamous cells - keratin production * Glandular epithelium - mucin production * Hepatocytes - bile production * Pancreas - insulin production

Question 32

What is an anaplastic tumour?

Answer 32

Tumours with little or no differentiation - lost morphological characteristics of mature cells and their orientation

Question 33

How does TNM staging work?

Answer 33

* Stands for 'Tumour, Node, Metastasis' * Grade - describes degree of differentiation (high grade = poor differentiation) * Stage - describes how far it has spread (high stage = greater spread) * Stage is more important

Question 34

Which of the following do well-differentiated tumours not have: • small number of mitoses • lack of nuclear pleomorphism • high nuclear-cytoplasmic ratio • relatively uniform nuclei • close resemblance to corresponding normal tissue

Answer 34

Well differentiated tumours do not have a: | • high nuclear-cytoplasmic ratio