Cytology

What should you do before sending a sample externally?

examine yourself to be sure it is of diagnostic quality

Why do you not use aseptic technique for surface cytologies?

asepsis will destroy pathologic changes

When would you use a fine needle biopsy?

to obtain a small sample of cells from an organ / mass

used in tissues that are highly vascular or have cells that exfoliate easily.

eg : lymph node, liver, spleen

What gauge needle would you use for a fine needle biopsy, why?

22G needle to reach the area of interest

o You can use 21G or 23G needles, but these are less ideal in most cases as 21G needles are wider and hence more likely to cause haemorrhage, and 23G needles are narrower so likely to yield fewer cells.

Describe how to do a fine needle biopsy

1. aseptically prepare area of skin over sampling target

2. use 22g needle, insert into skin, withdraw without leaving the skin and redirect to sample different areas.

3. remove needle and apply pressure to stop haemorrhage

4. use a full syringe to expel air onto slide

5. use a second slide to smear

6. air dry, stain (DiifQik), observe

When would you use a fine needle ASPIRATE biopsy?

to obtain a small sample of cells from an organ / mass

used in tissues that are highly structured and don’t exfoliate easily

eg spindle cell mass, muscle

What is the difference between aspirate and non-aspirate needle biopsy?

aspirate requires NEGATIVE PRESSURE

What are impression smears used for?

Ulcerated masses, pustules, cut surfaces of mass.

highly exfoliative tissues only!

describe the steps of an impression smear

gently blot the surface of the area to remove and blood ect.

press the cut surface / tissue onto slide

air dry, stain (DifQuik) observe

What are tape strips used for?

Surface infectious agents - skin cytology. eg bacteria!

describe stages of a tape strip

1. measure tape to be slightly longer than slide

2. attach to non-frosted end of slide

3. press tape numerous times into area of interest

4. stain with B and C diffquik only! (A will melt the glue)

5. rinse tape with distilled water

6. stick tape to slide, then allow to dry.

When you when a swab to sample?

skin surface cytology - vaginal, ear canal, conjunctiva.

Describe the steps of a swab sample

1. roll all sides of swab over area on interest

2. roll swab from one end of slide to the other

3. if greasy heat-fix

4. stain!

What is the purpose of urine sediment analysis?

concentrate and solids in urine into a small volume via centrifuging, then removal of supernatant fluid.

Allows evaluation of crystals, leucocytes, and erythrocytes in urine.

Describe how normal urine should appear under microscope

Little - no cells present, only transitional or squamous epithelium from urinary tract.

Why might rbcs be present in a healthy entire female

she is in oestrus

What is the term for leucocytes in urine, and what does this indicate?

pyuria

urinary tract inflammation

List three common crystals found in urine, and their appearance.

Struvite (triple phosphate)

• coffin lid

Calcium Carbonate

• round with radial striations

Calcium Oxalate

• diagonal cross - envelop like.

Describe the steps of urine sediment analysis

1. invert sample 6-7 times to mix

2. place 1ml in Eppendorf centrifuge tube, do twice

3. place the opposite in centrifuge (to balance)

4. centrifuge at 1500rpm for 2 or 10 mins.

5. remove supernatant fluid using pipette

6. place a drop of sediment on slide, use a cover slip, examine wet.