Clinical pathology

Question 1

What is a tumour?

Answer 1

Any kind of mass forming lesion. May be neoplastic, haematomous or inflammatory. A tumour doesn’t describe a cause. It is a mass occupying lesion! (a lesion is an area of damage to a tissue)

Question 2

What are the two basic components of a tumour?

Answer 2

1. Proliferating neoplastic cells parenchyma. 2. Supportive stroma.

Question 3

What is a neoplasm?

Answer 3

The autonomous growth of tissue which have escaped normal constraints of cell proliferation. You can have a neoplastic tumour. Neoplasms can be benign or malignant.

Question 4

What is a cancer?

Answer 4

A malignant neoplasm.

Question 5

Nature of lethality of benign tumours?

Answer 5

Can kill. Usually because of their location e.g. brain.

Question 6

How are benign and malignant tumours named? Difference between malignant names?

Answer 6

Benign ends in ‘-oma’. Malignant tumours are called Carcinomas or Sarcomas. Carcinomas ARISE from EPITHELIAL tissues (inside lining of colon, breast, lung, prostate…), whereas sarcomas ARISE from mesenchymal tissues such as bone, muscle, connective tissue, fat.

Question 7

What is dysplasia?

Answer 7

Dysplasia is a tumour that has disordered growth, but limited to epithelium, so hasn’t invaded yet – so may signify a stage preceding the development of cancer.

Question 8

LIST the differences between benign and malignant tumours. (x4)

Answer 8

Malignant tumours differ because they… …invade local tissues. …metastasis. …also vary in how they look – differentiation. …growth pattern.

Question 9

EXPLAIN the differences between benign and malignant tumours. (x2, x1, x5, x1)

Answer 9

INVASION: means DIRECT EXTENSION into the ADJACENT connective tissue or other structures e.g. blood vessels (allow spread to other areas of the body). Invasion is defined as the point it gets through the basal membrane!

METASTISIS: spread from primary site via blood vessels and other systems to other parts of the body. ALL malignant tumours have this ability, although it may be diagnosed before then. Benign remain localised.

DIFFERENTIATION: means how much do the cells of the tumour resemble the cells of the tissue it is derived from. For example: • Tumour cells tend to have large nuclei. • Cells have loss of normal features. • More mitoses than the normal tissue. • They have abnormal mitoses (three daughter cells from each mitosis rather than two) OR nuclear pleomorphism (vary a lot from each other in each cell). • Cells themselves may also vary in size and shape.

GROWTH PATTERN: means how much does the ARCHITECTURE of the tumour resemble the architecture of the tissue it is derived from. Tumours have less defined architecture. (Look at photo.)

Question 10

Which routes do malignant neoplasms spread? (x5)

Answer 10

Direct extension – invasion through basal membrane into local tissue. Haematogenous – spread by blood vessels. Usually through venules and capillaries, rather than arteries, because walls are thinner. Liver and lungs are common sites due to venous drainage. Lymphatic – via lymphatics to lymph nodes and beyond. Spread by normal lymphatic drainage of the organ. Evokes an immune response which caused nodal hyperplasia. Transcoelomic – via seeding of body cavities e.g. pleural cavities and peritoneal cavities. Once cancer is in a cavity, cancer will spread EVERYWHERE. Perineural – via the nerves.

Question 11

How does the body respond to direct extension? (x3)

Answer 11

THE BODY CAN RESPOND TO THE TUMOUR: …can be an immune response; …a vascular response when the body produces new blood vessels (angiogenesis); …growth of fibroblasts and connective tissue around the tumour = desmoplastic response.

Question 12

What is the cancer STAGE? How can this be determined? (x2, x2, x1)

Answer 12

Stage tells us how far the tumour has spread. TNM system! TNM is each rated with a number. T = tumour: size and extent of LOCAL invasion. N = nodes: has it spread to lymph nodes, in which case, how many has it spread to? M = are there distant metastasises (number of secondary malignant growths)?

Question 13

What is grade in relation to cancer? (x2 points)

Answer 13

How differentiated the tumour is (how different the tumour cells are from healthy tissue they are derived from). Also based on the numbers of mitoses.

Question 14

Which, out of stage or grade, is most important when predicting prognosis?

Answer 14

STAGE.

Question 15

What are carcinogens?

Answer 15

Agents that cause genetic damage and induce neoplastic transformation of cells – can therefore lead to cancer.

Question 16

What are the three types of carcinogens?

Answer 16

Chemical carcinogens, radiation, microbial carcinogen (mainly viruses).

Question 17

Three types of chemical carcinogen? List common chemical carcinogens and the cancers that they cause. (x2, x2, x3)

Answer 17

DIRECT ACTING AGENTS (do not require metabolism for activation – can cause permanent DNA damage): Dimethyl sulphate – nasal cavity; Diepoxy butane. PROCARCINOGENS (require metabolism for activation – can cause permanent DNA damage): Beta naphthylamine – oesophageal, lung and stomach cancers); Benzidine (bladder and pancreatic cancer). PROMOTERS (reversible DNA damage): hormones (e.g. oestrogen), drugs, phenols.

Question 18

List common radiation causes of cancer, and the cancers that they cause. (x2)

Answer 18

Ultraviolet light (skin cancers: melanoma, basal and squamous cell carcinomas); Ionising electromagnetic waves (X-rays).

Question 19

List common microbial carcinogens, and the cancers they cause. (x3 – x2, x1, x1)

Answer 19

Mostly viral. DNA oncogenic viruses: HPV (cervical), Hepatitis B (liver). RNA viruses: HTLV-1 (leukaemia/lymphomas). Bacterial carcinogens: Helicobacter Pylori (stomach).

Question 20

What is a Coroner?

Answer 20

Independent judicial official that investigates the circumstances of certain categories of death.

Question 21

What cases must be reported to the coroner? (x11)

Answer 21

1. If cause of death is unknown. 2. The deceased has NOT BEEN SEEN by the certifying doctor either after death or within the 14 days before the death. 3. If the death was violent, unnatural or suspicious. 4. Death MAY be due to an accident (WHENEVER it occurred) e.g. child gets hit by a car and has epilepsy as a result of it for the rest of their life. Same person dies at 80 because of an epileptic fit. That person MUST be submitted to the coroner. 5. Death MAY be due to neglect by self or others – very subjective. 6. Death that MAY be due to industrial disease or due to the deceased persons employment. 7. Death MAY be due to an abortion. 8. The death occurred during an operation or before recovery from the effects of an anaesthetic. Ambiguity because some people who have a serious problem are kept under anaesthetic, even before/after surgery. So generally, the definition extends to death that happens INSIDE the operating room. 9. MAY be a suicide. 10. Death occurred during or shortly after detention in police or prison custody. Includes anyone under police custody in a hospital. 11. Death MAY be due to poisoning.

Question 22

What are the types of autopsy?

Answer 22

Coroner’s autopsy and consented hospital autopsy.

Question 23

What is the purpose of a coroner’s autopsy? (x2)

Answer 23

Conducted to establish cause of death. Once cause of death is found, the remit is over.

Question 24

What is the purpose of a hospital autopsy? (x5)

Answer 24

Allow VERY thorough examination of the deceased and their disease. Identifying discrepancy between stated cause of death and actual cause of death. Monitoring effectiveness of new treatments. Teaching. Really useful for research e.g. knowledge of CJD relies heavily on study of post mortem brain tissue.

Question 25

What is the difference between a hospital and coroners’ autopsy apart from purpose? (x2)

Answer 25

Hospital: Requires consent from next of kin. Coroners: Requires no consent, although next of kin should be considered. Hospital: With consent, ANY material can be taken. Coroners: Material can only be taken if it bears upon the cause of death.

Question 26

Why do coroners’ autopsy not require consent from next of kin?

Answer 26

Death could be suspicious, and family could be responsible!

Question 27

What is the purpose of death certificates for the NHS?

Answer 27

Used for epidemiology. So, can help with funding allocation.

Answer 28

1a. Immediate cause of death. 1b. Predisposing factor THAT CAUSED 1a. 1c. Predisposing factor THAT CAUSED 1b. 2. Other factors that may have contributed to but not directly lead to death.

Question 29

What are the causes of sudden unexpected death? (x8 (x4 causes and x2 points; x1 and x2 points; x3; x2; x3 and x1 point; x0, x1 point, x0)) (What are the three most important ones? - most important ones in capitals)

Answer 29

CARDIAC SYSTEM: Cardiovascular disease – biggest cause. Hypertensive heart disease (heart conditions caused by high blood pressure). Cardiomyopathy (diseases of the muscle) Myocarditis (heart muscle inflammation) Top two are most commonly caused by cardiac arrythmia and you would most often see severe coronary artery atherosclerosis in a post mortem (quite obvious). VASCULAR SYSTEM: Ruptured aortic aneurysm – associated with atherosclerosis and hypertension. 5 CENTRAL NERVOUS SYSTEM: Non-traumatic subarachnoid haemorrhage Intracerebral haemorrhage. Epilepsy (sudden, but it’s not a surprise – people would know they have it). Respiratory system: Pulmonary embolus. Asthma Gastrointestinal tract: NOT USUALLY UNEXPECTED because you would usually be vomiting blood etc. – lots of previous symptoms. Bleeding oesophageal varices. Bleeding ulcers. Pancreatitis. Drugs Alcohol – not usually a cause of sudden unexpected death but leads to GI and trauma. Trauma.

Question 30

Types of injury? (x5)

Answer 30

Bruise. Abrasion. Laceration. Cut. Stab.

Question 31

What is a bruise? (x3 points)

Answer 31

What is a bruise? (x3 points) A blunt trauma injury. Skin intact. An extravasated (forced out from vessel) collection of blood which has leaked from damaged arteries, venules and veins, BUT NOT CAPILLARIES. NB: never attempt to age or describe a bruise. For example, may look like a bite, but NEVER say it is.

Question 32

What are the physiological risk factors for bruising? (x3)

Answer 32

More easily where skin is lax (slack). Fragile vessels. Cannot properly coagulate.

Question 33

What is an abrasion? (x2 points)

Answer 33

A graze or scratch. The most superficial of blunt trauma injuries. Confined to epidermis.

Question 34

What is a laceration? (x5 points)

Answer 34

A split to the skin. By definition, it is the result of blunt force overstretching the skin. Usually pass through the full thickness of skin. Margins are usually ragged (meaning torn and rugged) with crushing and bruising. Common where skin can be compressed between force and underlying bone e.g. scalp.

Question 35

What is a cut?

Answer 35

Length of injury is longer than its depth. Caused by sharp object. Edges are clean cut, so minimal injury to surrounding tissue.

Question 36

What is a stab?

Answer 36

Depth of wound is longer than its width.

Question 37

Important clinical implication of naming cuts, lacerations…

Answer 37

NB: IF YOU DON’T KNOW WHAT TO CALL IT, CALL IT AN INJURY OR WOUND – people can get trouble in court if it’s unclear and you categorise it. And, don’t class everything as a laceration like other clinicians do.