Tumour classification and behaviour

Question 1

What processes is cellular proliferation important for?

Answer 1

Embryogenesis, normal tissue homeostasis, healing and repair, response to increases demand.

Question 2

What is a labile tissue?

Answer 2

The cells divide regularly and rapidly and spend little time in G0. eg the skin, gut and bone marrow.

Question 3

What is a stable tissue?

Answer 3

The cells that show little division. eg. the liver

Question 4

What are perninant cells?

Answer 4

Those which never or very rarely divide, ege neurons or the myoceridiocycles.

Question 5

What is metoplasia?

Answer 5

The replacement of one normally differentiated tissue type with another, normally in response to a change in the environmental stimuli.

Question 6

Define a tumour?

Answer 6

An abnormal mass of tissue formed by excessive proliferation of cells as a result of an irreversible genetic change which is passed from one tumour cell to its progeny.

Question 7

How is a tumour classified?

Answer 7

By its biological behavior and the cells type from which the tumour has arisen (histogenesis or differentiation).

Question 8

What are the four main pathways a tumour can spread by?

Answer 8

Local, lymphatic, blood and transcoelomic.

Question 9

Describe local spread.

Answer 9

Cells insinuate themselves between adjacent normal cells and invade along tissue planes, even if the tumour appears grossly well-defined. Dense collagenous tissues such as fascia or periosteum tend to act as a barrier to some extent.

Question 10

Which cancers can spread via the lymphatics?

Answer 10

Carcinomas, early event. eg breast cancer patient have palpable axillary lymph nodes. Melanomas and sarcomas rarely spread via the lymphatics.

Question 11

How to cancers spread from the lymphatics to the blood?

Answer 11

Via the thoracic duct

Question 12

Which cancers spread by the blood?

Answer 12

Sarcomas, early event, mostly to the lungs. Carcinomas but normally after the lymphatics, an expection is renal carcinoma as it spreads along the renal vein and sometimes the inferior vena cava. Bowel tumours spread via the mesenteric veins to the liver but initially to the mesenteric lymph nodes.

Question 13

Which cancers can spread blood to bone?

Answer 13

Many carcinomas, usually to the spine through the pre-vertebral venous plexus.

Question 14

Is spread by the arteries common? Why?

Answer 14

No, the walls are to thick. Some cases of lung cancer can but may initially be via the pulmonary veins.

Question 15

What is transcoelomic spread and some examples?

Answer 15

Spread across the body cavity. Intra-abdominal tumours like ovarian carcinoma. Krukenberg tumours spread from gastric carcinoma to both ovaries. Rare in both melanomas and sarcomas.

Question 16

How, is it thought, do cells lodge in a site of metastases?

Answer 16

Via mutated surface receptors like CD44. Similarly to normal lymphatic circulation.

Question 17

What are the clinical effects of benign tumours?

Answer 17

palpable lumps, pressure or expansion effecting adjacent tissues (like blocking a hallow viscus), effects due to the substances produced (eg endocrine hormones causinf hyperthyrodism due to a thyroid tumour).

Question 18

Whats are the local effects of a malignant tumour?

Answer 18

Palpable mass (grows rapidly and may be painful), carincomas often ulcerate and bleed as they outgrow the bloody supply, Can cause iron-deficiency anaemia. Carcinomas of a hollow viscus many cause stenosis or complete obstruction.

Question 19

What are the metastatic effects of a malignant tumour?

Answer 19

Multiple metastases masses have similar effects as the primary mass, but as there are more the outcome is more severe.

Question 20

What are the non-metastatic effects of a malignant tumour?

Answer 20

Wasting (cachetic). weight and appetite loos, feeling unwell. Anaemia and febrile (have a fever). Normally due to the increas in cytokines eg IL-1 and TNF.

Question 21

What are paraneoplastic syndromes and what causes them in metastatic cancers?

Answer 21

Separate diseases which arise as a consequence of cancer, often due to inappropriate generation of hormones. e.g. the secretion of ADH in small-cell carcinoma of the lung will cause dilutional hyponatraemia. PTHrP produced by many carcinomas leads to hypercalcemia (behaves like PTH and activates osteoclasts).

Question 22

Where can cancer cells easily be found for cytology diagnosis?

Answer 22

Urine, sputum, fluid from the pleural cavity or peritoneum.

Question 23

Which methods are used to diagnosis cancer?

Answer 23

Clinical, radiological, biochemical and cytology.

Question 24

What is the difference between a cancers grade and its stage?

Answer 24

The grade is its basic biological nature and the stage describes the extend of its development.

Question 25

What is the TNM system and how does it work?

Answer 25

A staging system used particularly for carcinomas. The increasing number describes the increasing development of the disease at each site. T is the primary site, N is the draining lymph nodes and M is the distant sites of metastasis.

Question 26

How to the nuclei of benign and metastatic cancer cells differ?

Answer 26

In benign cancers they are small and regular, compared to malignant tumours were they are large and pleomorphic (more DNA).

Question 27

What does the histogenesis and differentiation of a cancer cell describe?

Answer 27

Histogenesis: where we think the cell arose from. Differentiation: what the cell looks like.

Question 28

What are the effects of lung cancer?

Answer 28

Cough, harmoptysis, chest pain, pneumonia, pleural effusion. Metastases to the bone liver and brain.

Question 29

Breast cancer effects

Answer 29

Lump, early spread to the nodes, bone, lung and liver.

Question 30

Colon cancer effects.

Answer 30

Altered bowel habit, obstruction, anaemia, metatstases to the liver.

Question 31

Prostate cancer effects

Answer 31

Urinary symptoms, metastases to the bone

Question 32

Pancreatic cancer effects

Answer 32

obstructive jaundice, back pain.

Question 33

Kidney cancer effects

Answer 33

mass, haemateria, metastases to the lung and bones

Question 34

Oesophagial cancer effects

Answer 34

Dysphagia, anaemia, early local spread and metastasis.

Question 35

Lymphoma effects

Answer 35

lymph node enlargment, infection, bone marrow replacement.

Question 36

Leukaemia effects

Answer 36

anaemia, infection and bleeding.