13. Pathology

Question 1

what is the definition of pathology?

Answer 1

1. the medical science concerned with all aspects of disease including the essential nature, causes, development as well as the structural and functional changes that result from the disease process
2. the anatomical or functional manifestation of a disease

Question 2

what are some specialities under pathology?

Answer 2

1. toxicology
2. immunology
3. chemical pathology
4. forensic medicine
5. microbiology
6. veterinary pathology

Question 3

why is there lots of sub-specialisation in pathology?

Answer 3

due to the amount we now know about disease

Question 4

what are signs and symptoms?

Answer 4

Signs = things that you can measure linked to disease like blood pressure
Symptoms = what the patient is feeling that leads them to seek healthcare

Question 5

how can you make a diagnosis?

Answer 5

1. usually what you see and what you can measure is enough
2. Sometimes more invasive examination is needed to confirm diagnosis or rule out more serious things
   Including: blood tests, imaging, core biopsy, bone marrow biopsy

Question 6

what is an excisional biopsy?

Answer 6

removing the whole lesion in the process of diagnosis

Question 7

what is an incisional biopsy?

Answer 7

small sample for diagnosis
checking for margins

Question 8

what is a punch biopsy?

Answer 8

taking just a bit of the tissue from inside the lesion

Question 9

what is a shaving biopsy?

Answer 9

taking a cutting from the surface of the lesion especially if it is on the skin

Question 10

what is an endoscopic biopsy?

Answer 10

A small internal biopsy that samples atypical regions of organ surfaces.
They can also be used to do general mapping of the area

Question 11

What is a resection specimen?

Answer 11

A whole tissue or organ sample removed during surgery

Question 12

when do resection specimens not go through full lab testing?

Answer 12

if previous tests have determined it is benign

Question 13

how are resection specimens analysed in a pathology lab?

Answer 13

1. not always a full analysis, microscopy could just be enough to make a diagnosis
2. stitches and dyes are used to help orientate the tissue to match with the body used to inform surgeons about what still needs to be removed and resection margins and inform targeted therapy
3. get information about the patient from the specimen

Question 14

what questions can histopathology answer?

Answer 14

1. what is it?
2. where is it from?
3. what is it effecting?
4. are the margins good?
5. what treatments are best suited?

Question 15

what are the steps of a histopathology sample?

Answer 15

1. cut-up the surgical specimen
2. embedding in paraffin (most samples arrive partially embedded)
3. Sectioning
4. histology slide making = slicing and staining
5. diagnosis using a microscope

Question 16

what is a hysterectomy?

Answer 16

a resection of the uterus, fallopian tubes and ovaries

Question 17

what are fibroids?

Answer 17

tumours made of smooth muscle

Question 18

when are fibroids benign?

Answer 18

if they are multiple and small

Question 19

when are fibroids usually malignant?

Answer 19

if it is one large mass then it could be a sarcoma

Question 20

what is the uterus wall made of?

Answer 20

smooth muscle

Question 21

Histology of a benign fibroid

Answer 21

1. Mostly pink
2. spindle cells with bland nuclei
3. mitosis not really occurring or easy to identify
4. no necrosis or haemorrhage

Question 22

Histology of a malignant fibroid?

Answer 22

1. all the cells look different
2. atypical nuclei
3. haemorrhage
4. lots of mitosis

Question 23

how is breast cancer spread determined in surgery?

Answer 23

1. look at the central lymph node
2. drains the tumour
3. if the cancer is in the lymph node then it needs to be removed
4. removal of lymph nodes comes with comorbidites
5. if the tumour reaches the skin then the staging increases

Question 24

Histology of invasive breast carcinoma

Answer 24

1. medium sized cells
2. atypical nucleus
3. need to test for specific markers like oestrogen and progesterone to give treatment recommendations
4. use immunohistochemistry to test for receptors
5. triple negative is biologically more effective but less responsive to treatment

Question 25

histology of a soft tissue sarcoma

Answer 25

1. very small dot like cells = myxoid 2. some cells with a vacuole 3. vacuole indicates making fat with means it is a liposarcoma 4. due to the tumour type radiotherapy works really well to kill the tissue and turn it into scar tissue and solid lump rather then a soft tumour liable to burst 5. still need surgery but a lot easier to remove

Question 26

what is the purpose of fresh and frozen samples taken from surgery?

Answer 26

1. real time analysis 2. look for resection margins 3. check you have the whole tumour with no damage to blood vessels or nerves 4. much simple then with fixed samples as it can be ready in 30 mins opposed to a few days

Question 27

why can you not give a definitive diagnosis off a frozen sample?

Answer 27

1. frozen cells have gone through massive trauma so they lose details and structures unless they are very obvious 2. need to ensure you have enough tissue to do extra analysis 3. Verify diagnosis after fixing samples and reanalyse to give diagnosis a few days later

Question 28

what needs to be remembered about frozen samples?

Answer 28

if the patient was contagious then the tissue could pose an infection risk

Question 29

what stains are mainly used in pathology?

Answer 29

H&E stains or other dyes that are cheap and easy to use NOTE there are other specialist dyes

Question 30

What can immunohistochemistry tell us?

Answer 30

1. what antigens are expressed by the tissue 2. Presence of viruses 3. helpful for diagnosis and prognosis

Question 31

what is FISH used for?

Answer 31

1. genetic testing 2. Normally to identify translocations

Question 32

what has surpassed FISH?

Answer 32

Next generation sequencing

Question 33

what are the limits of histopathology examination?

Answer 33

1. taking non-diagnostic or wrong bits of the tissue like necrotic tissue or capsules 2. too little tissue to be able to examine it properly 3. the tissue is very brittle and can fall apart 4. the morphology is extremely hard to interpret 5. histological diagnosis needs to be correlated with the other clinical findings and imaging 6. complex cases involve the input of lots of healthcare professionals

Question 34

what is a relatively new tumour phenotype and what does it mean?

Answer 34

1. translocation of TRK 2. expresses CD34 and S100 3. it has unknown malignant potential 4. tumours described by mutation are hard to diagnose by pathology as you cannot see a mutation

Question 35

how can pathology contribute to the increase in medical knowledge?

Answer 35

1. new entities and help correlate disease with behaviour 2. could help link therapies with tumours and targets 3. use what you know about tumours and look at the similarities between it and the new/rare tumour to inform treatment