Cytology Flashcards
In which situations should you not aseptically prepare a site for a sample?
Surface cytologys
What are fine needle aspirate biopsies used for?
To obtain small samples of cells from inside organs or masses
In which patients is it inappropriate to take a FNA sample?
Coagulation defects or highly vascular masses as it might cause haemorrhages
A fine needle biopsy is useful in which kinds of tissues?
Lymph node, spleen and liver, where cells exfoliate easily, or where blood contamination of the sample is a likely problem
Describe the steps of getting a fine needle biopsy sample
o Prepare the skin over the mass aseptically
o Secure the mass with your non-dominant hand
o Insert a 22G needle to reach the area of interest
o WITHOUT REMOVING THE NEEDLE FROM THE SKIN redirect it several times within the tissue, to sample several different areas.
o Remove the needle from the mass and apply pressure to the sample site to reduce haemorrhage.
During a fine needle biopsy, once you have your sample in the needle, what are the next steps?
o Draw up 5ml of air in the 5ml syringe THEN connect it to the sample needle.
o Hold the needle, bevel down, just above one of the microscope slides.
o Vigorously expel the air, to push the contents of the needle on to the slide surface
o Take another clean microscope slide and lay it atop the one with the sample on it.
o Slide them one over the other in one direction only, to smear the sample over both slides.
o Air dry.
In which tissues is a fine needle aspirate biopsy useful?
Useful for tissues which don’t exfoliate well, such as muscle and spindle cell masses. High chance of blood contamination of samples in vascular tissues
How does a FNA biopsy differ to a fine needle biopsy?
- The same, but attach a 2.5ml or 5ml syringe to your 22G needle before introducing it to the mass
- Insert the needle in the mass as before and draw back on the syringe – 2 or 3ml
- Maintain this negative pressure and KEEP THE NEEDLE IN THE TISSUE while redirecting the needle several times
In which tissues is an impression smear useful?
Ulcerated masses, burst pustules or to take from the cut surface of a mass
Describe the steps in obtaining an impression smear
- Remove the tissue sample from the glove
- Gently blot the surface to remove blood contamination
- Press the cut surface of the sample on to the face of a clean slide
- Allow to air-dry
What is a tape strip sample most often used for?
Skin cytology
What are the steps in obtaining a tape strip sample?
- Do not aseptically prepare the area
- Measure out a strip of Sellotape which is about 2cm longer than your microscope slide.
- Attach it round one end of your slide
- Press the centre of the tape to the area of interest (between your fingers or behind your ear might be good!)
- Now bring the tape round the other side of the slide and attach it about halfway down, so you end up with a loop
How should you stain a tape strip sample?
Stain the loop in the RED (Solution B) and BLUE (Solution C) components of the Diff-Quik stain ONLY; do not use the fixing solution (A) as this will melt the glue on the tape.
After staining, what do you do to the tape strip sample?
• Unstick the end of the tape from halfway down the slide, and bring it all the way round so you have the tape stuck all the way
down one face of the slide and attached over each end
• Lay the slide on some tissue and blot GENTLY with tissue paper to squeeze out the extra stain
What is a swab sample most commonly used for?
Surface cytology – conjunctiva, ear canal, interdigital, vaginal etc
