Cytology of effusions (Yr 3)

Question 1

what are the features of the serous fluid that facilitates movement in the cavities?

Answer 1

low cellularity
low total protein
(it is an ultrafiltrate)

Question 2

what are the three things that dictate the amount of fluid in the body cavities?

Answer 2

hydrostatic pressure
oncotic pressure
permeability of vessels

Question 3

what is the usual cause of transudate effusions?

Answer 3

imbalances in hydrastatic/oncotic pressure

Question 4

what is the usual cause of exudate effusions?

Answer 4

increased vascular permeability due to inflammation

Question 5

how can you tell if a effusion sample is iatrogenically contaminated with blood?

Answer 5

initially clear then blood (or vice-versa)
swirling of blood
blood will clot
see platelets under microscope

Question 6

how can you tell if the blood in the effusion is from true body cavity haemorrhage and not just iatrogenic?

Answer 6

fluid doesn’t clot
supernatant often haemolysed
no platelets and erythrophagocytosis under microscope

Question 7

how do chyle effusion appear?

Answer 7

milk, white, opaque

Question 8

what is the usual location of a lesion causing a chylous effusion?

Answer 8

thoracic duct (heart disease, trauma, neoplasia, idiopathic)

Question 9

what cytology would you expect from chylous effusions?

Answer 9

lots of lymphocytes (it is lymph)
high triglycerides

Question 10

how can you tell if an effusion is chyle or pseudochyle?

Answer 10

measure triglycerides
(pseudochyle has low triglycerides and is white due to protein, cholesterol or cell debris)

Question 11

how do transudates appear?

Answer 11

clear and colourless
(TRANSlucent)

Question 12

what is the cytology findings of transudates?

Answer 12

low protein
low cells (some monocytes and macrophages)

Question 13

what is the typical cause of transudate effusions?

Answer 13

hypoalbinaemia (protein losing enteropathy, protein losing nephropathy, reduced protein production from liver)

Question 14

what should be done if you drain a transudate effusion?

Answer 14

measure albumin/creatinine
urinalysis (UPCR)
imaging
look for GI and renal disease

Question 15

what cytology is found in modified transudates?

Answer 15

more protein than transudates
low cellularity (few more than transudate)

Question 16

how do modified transudates usually appear?

Answer 16

straw coloured
clear

Question 17

what is the typical cause of modified transudate effusions?

Answer 17

high intravascular hydrostatic pressure…
CHF, thrombi, neoplasia

Question 18

what is the findings on cytology of exudates?

Answer 18

high proteins
high cells (lots of neutrophils)

Question 19

how do exudates appear?

Answer 19

turbid/viscous (lots of cells)
yellow/brown/bloody

Question 20

what is the main process involved in exudate formation?

Answer 20

inflammation (hence get lots of neutrophils)

Question 21

what causes the exudate associated with FIP?

Answer 21

vasculitis caused by the virus

Question 22

how does FIP exudate appear?

Answer 22

yellow stick fluid

Question 23

what further tests should be done in cases that you suspect FIP due to the exudate sampled?

Answer 23

serology
immunohistochemistry of fluid for coronavirus
(no single test make definitive diagnosis apart from histopathology)

Question 24

what are the findings on cytology of a bile peritonitis?

Answer 24

neutrophils
macrophages with green pigment
bilirubin concertation in exudate higher than in the plasma

Question 25

how can you tell from fluid in the peritoneum that there is a bladder rupture?

Answer 25

creatine concentration in the fluid sampled will be higher than in plasma

Question 26

how does the fluid in the peritoneum due to a ruptured bladder change overtime?

Answer 26

fluid starts as transudate but as the urea irritated the cavity it causes inflammation and changes to an exudate

Question 27

what are the cytology findings of synovial fluid?

Answer 27

low cells
high protein