Cell Pathology Flashcards
Define atrophy
Shrinkage in the size of a cell and consequently the size of a whole organ, by the loss of cell substance
-We see a decrease in weight of an atrophic organ
Define hypertrophy
- Increase in the size of a cell and consequently the size of a whole organ
- Physiological or pathological
- important because muscle cells cannot divide in adult life so this is the only way in which an organ can get bigger (number of cells remain constant but there is an increase in cell size)
Define hyperplasia
- Increase in the number of cells in an organ
- Physiological or pathological
Define metaplasia
- Reversible change in which one normal adult cell type (mature cell) is replaced by another (normal adult cell replacement)
- Physiological or pathological
Define dysplasia
- Precancerous cells which show the genetic and cytological features of malignancy but do not invade the underlying tissue
- bridge between normality and cancer
- not invaded the basal lamina
- dysplasia is a worrying change
List the 5 adaptive responses of cells
Atrophy, hypertrophy, hyperplasia, metaplasia and dysplasia
Give an example of atrophy
- Gastric atrophy causing pernicious anaemia (anaemia resulting from deficiency of vitamin B12)
- posterior cortical atrophy from the loss of neurones in Alzheimer’s disease
Give an example of hypertrophy
Physiological: muscle hypertrophy in the uterus during pregnancy
Pathological: left ventricular hypertrophy in response to hypertension
Give an example of hyperplasia
Physiological: oestrogen-induced endometrial hyperplasia
Pathological: benign prostatic hyperplasia, carcinoma
Give an example of metaplasia
Physiological: metaplasia in the cervix
Pathological: Barrett’s Oesophagus (otherwise known as columnar lined oesophagus)
Give an example of dysplasia
- Cervical intraepithelial neoplasia
- Barrett’s oesophagus is associated with a much greater risk of oesophageal cancer because metaplasia is typically followed by dysplasia
- dysplasia is the increased cancer risk
Define degenerative
Change of a tissue to a lower or less functionally active form
Define ulcer
Local defect or excavation of the surface of an organ or tissue, produced by the sloughing of necrotic inflammatory tissue
Recall the light microscopic changes of reversible cell injury
- fatty changes
- cellular swelling
Recall the light microscopic changes of irreversible cell injury
The different types of necrosis (coagulative, liquefactive, caseous and fat)
Specific cases reported to the Coroner in England and Wales
- When the cause of death is unknown
- When the deceased has not been seen by the certifying doctor either after death or 14 hours before death
- If the death was violent, unnatural or suspicious (example of a homicide)
- When the death may be due to an accident, regardless of when this occurred
- The death may be due to neglect by self or by others (subjective and difficult to define)
- The death may be due to an industrial disease or due to the deceased person’s employment (occupational such as mesothelioma linked to asbestos exposure)=includes accidents at work and if the death is actually at work
- The death may be due to the impact of abortion on the mother
- The death occurred during an operation or before recovery from the effects of anaesthetic
- The death may be a suicide
- The death may be related to poisoning
- The death occurred during or shortly after detention in police or prison custody (expection of DoLS=patients lack capacity to consent to their care and treatment)
Difference between a coroner’s autopsy and a hospital autopsy
Purpose and consent
Coroner’s autopsy purpose
- Conducted to establish the cause of death
- Once the Coroner has determined the cause of death, his remit is over
Hospital autopsy purpose
- Allows a very thorough examination of the deceased, the extent of their disease, their treatment and its effects
- Performed in the case of an audit where there is a major discrepancy between the stated cause of death and the actual cause of death
- Used for medical teaching purposes
- Used to monitor the effectiveness of new treatments
- Used in medical research (knowledge of variant CJD heavily relies on the study of post mortem brain tissue)
Define bruise
- Otherwise known as a contusion
- extraversated collection of blood which has leaked from damaged small arteries, venules and veins but not capillaries
Define abrasion
- graze or scratch
- most superficial of the blunt trauma injuries
- confined to the epidermis
Define laceration
-split to the skin as a result of blunt force trauma which overstretches the skin
Define a cut
- Otherwise known as a slash
- Split in the skin where the length of the injury is longer than its depth
Define a stab
- Otherwise known as a penetrating injury
- Split in the skin where the depth of the wound is greater than the width
Define incised wounds
- often discrepancy in terms used
- to some this means cuts and stabs
- to others it means the same as cuts
Define cancer
- malignant neoplasm
- an abnormal growth of cells which tend to proliferate in an uncontrolled way and, in some cases, to metastasise
Define neoplasm
- The autonomous growth of tissue which have escaped the normal constraints of cell proliferation
- all body cells divide and grow under tight control, but a neoplasia will develop when this control is lost
- growth in uncoordinated, independent of the body’s normal homeostatic growth-regulating mechanisms, purposeless and will continue after the stimulus which initiated the change is removed/ceased
- example of a neoplastic tumour is lung cancer
Define tumour
- any kind of MASS forming lesion
- abnormal swelling in or on a part of the body
- may be neoplastic, hamartomatous or inflammatory
- Example of a non-neoplastic tumour is nasal polyps with a chronic inflammatory cause
- usually applied to the abnormal growth of tissue (benign or malignant)
Define metastasis
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Define carcinogens
-any substance that, when exposed to living tissue, may cause the production of cancer
Define malignant
- classification of neoplasm
- invade tissue locally and have the potential to spread to distant sites in the body
- more difficult to remove because of local tissue invasion and metastasis
- Local surgery helps but focus is on chemo and radiotherapy
Define benign
- classification of neoplasm
- remain localised=defined, well demarcated
- cured by local surgery (easy to remove)
Example of a situation resulting in a bruise
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Example of a situation resulting in an abrasion
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Example of a situation resulting in an laceration
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Purpose of cancer screening
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Features/principles of a successful cancer screening programme
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Environmental carcinogen examples
- UV radiation= basal cell carcinoma, squamous cell carcinoma and multiple myeloma
- Asbestos=mesothelioma linked to cases reported to a coroner
- Ionising electromagnetic radiation=leukaemia and solid tumours
Chemical carcinogen examples
- Hydrocarbons
- Amines
- Nitrosamines
- Azo dyes
Infectious carcinogen examples (oncogenic viruses)
- Epstein-Barr virus (EBV)=Burkitt’s Lymphoma
- Human papillomavirus (HPV)=Cervical cancer
- Hepatitis B virus=hepatocellular carcinoma (liver)
- human herpesvirus-8=Kaposi sarcoma
- Helicobacter pylori (bacterium)=gastric cancer and lymphoma
Barrett’s Oesophagus
Epithelial lining of the oesophagus converts from stratified squamous to columnar (change of normal oesophageal tissue lining to that which resembles the lining of the small intestine)
Metaplasia in the cervix
- Endocervix is lined with columnar epithelium and the ectocervix is lined with stratified squamous epithelium
- At puberty/during pregnancy, the cervix expands and exposes the fragile columnar epithelial lining of the endocervical canal to the harsher more acidic environments in the vagina
- Causes metaplasia from columnar to stratified squamous
Cause of Barrett’s Oesophagus
Acid reflux
Treatment to reverse pathological metaplasia in Barrett’s Oesophagus
PPI’s (proton pump inhibitors) which inhibit acid production
Reversal of the physiological metaplasia in the cervix
Cervix contracts and closes up
Properties of cells in the dysplastic stage
High nuclear-cytoplasmic ratio, increased mitoses, genetic abnormalities of cancer, do not invade through the basement membrane
Define necrosis
Confluent cell death associated with inflammation
Define apoptosis
Programmed cell death of single cells, not associated with inflammation
Define necroptosis
- Programmed cell death associated with inflammation
- Energy dependent
- Halfway between necrosis and apoptosis
- many causes such as viral infection
- generally occurs in pathological circumstances
Features of a bruise (contusion)
- blunt trauma injury
- occurs alone when the skin remains intact or can be associated with other injuries
- Occurs more easily where the skin is lax
- Factors effecting bruising include coagulation state and fragility of blood vessels
- Can take hours or days to form
- It is possible to bruise after death
- Bruises can be present in patterns and deep bruising can occur which is never seen on the skin surface
- don’t age bruise but can describe the colour
Features of an abrasion
- can occur before or after death
- caused by either a tangential force (force acting on the moving body in the direction of a tangent to the path of the body) or vertical force
- tangential force may be distal skin tag whereas the vertical force has no distal skin tag
- example of friction burn, whip, stamp etc
Features of a laceration
- will pass through the full thickness of the skin=deep and will bleed
- common where the skin can be compressed between the force and the underlying bone
- Rare over soft, fleshy areas like the buttocks and breasts
- Margins are ragged with crushing and bruising
- bridging fibres arch across the skin defect
- flaying=where a tangentially applied force leads to a horizontal laceration
- example of hammer, fall etc
Features of a cut or stab wound
- Caused by an object with a sharp or cutting edge (typically a knife but it can be any material such as broken glass etc)
- Edges of the wound are clean, defined and well demarcated(can distinguish the limits of the wound)
- Minimal injury to the surrounding tissue
- Information about weapon type can be gained from analysis of the wound (do not overinterpret though)
Causes of cell injury
G=genetic defects
I=infectious agents (bacteria, viruses, multicellular parasites)
N=nutritional imbalances
C=chemical agents (includes iatrogenic injury which is cell injury resulting from the drugs/medication that the doctors give)
H=hypoxia (oxygen deprivation)
A=aging
P=physical agents (eg: gunshot wound, trauma etc)
I=immunological reactions (autoimmune disease where the body attacks itself as in conditions such as rheumatoid arthritis)
Factors affecting the cellular response to injurious stimuli
- type of injury
- duration of the injury (how long the injury is sustained)
- the severity of the injury
Factors affecting the consequences of an injurious stimuli
- type of cell (some cell types are naturally more resistant to injury than others such as in the example of bone, fat, the brain and the heart to oxygen deprivation=differing metabolic requirements)
- The cell’s status (more vulnerable to various agents if in the process of dividing)
- adaptability (does the cell have particular adaptations it can undertake)
- The genetic makeup of cells
List the four intracellular mechanisms/systems which are vulnerable to cell injury (systems are linked so damage to one, will impact the others)
- cell membrane integrity
- ATP generation
- protein synthesis
- integrity of the genetic apparatus