histopathology Flashcards
what do you look for in a biopsy *
is it normal
is it inflammed - chronic/infected
cancer/tumour - what type - important becasue require different treatments
what are you looking for in resection specimens *
look at margins to see if it is clear from the tumour
is it inflammed
how far the cancer has spread - identify in the wall/outside nodes/ without cancer at all
see if all of the cancer has been removed
when are frozen sections taken *
during surgery
want to know if margins are clear
ave to make a rapid diagnosis
what are you looking for when you look at a frozen section *
is it cancer
is it all out
is there someting else going on
what is the difference between a hospital and coroner’s post mortem *
hospital - ordered by clinician because something went wrong, dont know why died
coroner’s - because the death was suspicious
describe how the sections are obtained *
specimen must be labelled properly
then fixed in formalin - this penetrates the tissue slowly
embedded in paraffin wax
cut using a microtope
specimen should be 4-5um
use HandE stain
what are done with the sections *
H and E normal stain can do others:
gram stain or ZN (positive for bacteria = red)
identify specific antigens using Ab - immunoistochemistry
carry out molecular tests
how do you get the sample for cytopathology *
look at individual cells
fine needle aspirations
in endoscopies when brushings of the tumour are taken
used in cervical and breast screening
fluids eg urine and ascities can be examined for cells
how long does it take a histopath result to reach clinician *
frozen section - 30 mins
biopsy 2-3 days - longer if need special stain/immune
resection 5-7 days - bigger so takes longer
importance of post mortums * N
educate drs
see why treatment didnt work
determine the cause of deat
show spread of disease
when might histapathologists make diagnosises *
on biopsies
rapidly with frozen sections
fromn material removed by surgery
benefits of cytology screening *
less invasive than histopathology
what samples are taken for cytology *
sputum
body fluids that contain cells
cervical smears
tissue obtained by fine needle aspiration
when would you need to use a frozen section
during surgery
to see if tumour
if margin of excision is adequate
if the lymph node is involved
if you have got the parathyroid
explain the use of immunohistopathology *
use Ab to identify specific antigens
eg see lymphocytes in lymph nodes
