pathology 2 - lesions

Question 0

examine the specimen - what do you want to know?

Answer 0

species and the tissue or organ involved. what was the history of the animal?

Question 1

3 main points when looking at a lesion?

Answer 1

1. examine and define specimen it came from?
2. describe any changes
3. draw conclusions and formulate a diagnosis

Question 2

describing any pathological changes present?

Answer 2

1. where is the lesion?

2. what is the lesion?

Question 3

ways to describe where a lesion is? (5)

Answer 3

1. focal - solitary/multifocal
2. diffuse - whole organ affected.
3. multifocal to coalescing (if they join up)
4. segmental - used to describe a tubular organ
5. miliary - multiple small lesions(could use multifocal)

Question 4

ways to describe - what is the lesion? (7)

Answer 4

1. size
2. shape
3. colour
4. consistency
5. odour
6. special
7. cut surface

Question 5

how can you determine the size of a lesion?

Answer 5

measure in 2/3 dimensions
or % of organ
or weight relative to animal
or volume of fluid again relative

Question 6

how do you determine the shape of a lesion?

Answer 6

circular, oval, nodular
what are the borders like? - smooth ragged , demarcated?
what is the surface like? - flat, elevated, depressed, umbilicated, pedunculated, sessile (broad base attachment)

Question 7

describing colour?

Answer 7

grey brown black white shiny/dull light/dark greeny/yellow

Question 8

hwo to describe consistency?

Answer 8

palpate if can. soft, firm, hard
slightly , moderate, marked
cohesion - friable/eleastic

Question 9

odour

Answer 9

e.g. kindey disease - smell ammonia on breath.

Question 10

special refers to?

Answer 10

fluid or blood or exudate present (if so sample it)

Question 11

cut surface??

Answer 11

examine drainage lymph nodes etc

Question 12

in order to draw conclusions, what would you need to know? - what if abattoir? what if euthanised?

Answer 12

history!!
how and when it died? - what sort of PM changes should you expect?
eg. in an abattoir organs are well bled and may look different. if euthanased then drugs may have had an effect e.g. spleen gets engorged.

Question 13

how can you tell if a lesion is after it died? PM change?

Answer 13

if it was after then it wont have any inflammation associated with it.

Question 14

When submitting to the lab - what is important if cant submit the whole specimen?

Answer 14

then send a part and explain exactly where it was etc. maybe include diagrams. communicate!!!

Question 15

interpretations depend on what? what does an atroventral lesion in lungs mean? what does multifocal suggest?

Answer 15

1. bronchopneumonia from head end - as resp pathogens would get there first. aerogenous portal of entry (inhaled)
2. multifocal implies that it was systemic/haematogenous spread.

Question 16

interp based on shape of lesion? raised implies? depressed implies? flat implies? demarcation implies?

Answer 16

raised - something has been added, eg. larvae, neoplasms
depressed- something has been lost eg. kidney disease - loss of tubualr tissue/ kidney cyst.
flat - acute process/incidantal colour change ‘melanosis’
demarcation - benign often well demarcated as grow by expansion
malignant - not case as can metastisise and invade.

Question 17

interp by size. what is important?

Answer 17

it is important that if you only submit part of it the you can explain where it was etc. in general larger = worse and multifocal = worse as it has spread/grown.

Question 18

intrp by colour? red/black? brown? pseudomelanosis? green? yellow? white? - what is a neoplasia?!

Answer 18

red - haemorrhage/congestion (haematoma if nodular)
(neoplasia =formation of new tissue abnormal)
brown - melanoma - tumour cells produce melanin pigment.
pseudomelansis - PM change due to production of hydrogen sulphide by bacteria - convert iron to iron sulphide. affects surface olny.
green- bile pigment eg. leeched and called biliary imbibition - PM change
yellow - fat, bilirubin, exudates, lipidosis, jaundice, neoplasms.
white - exudate, chylous fluid (rich lymphocytes) neoplasia, fibrous tissue (liver fluke = much fibrosis - white tracts)