15 – Intro to Cytology Flashcards
What is cytology?
- Microscopic assessment of cells from body tissues or fluids
What are the advantages of cytology?
- rapid
- inexpensive
- minimally invasive
- can be done in-clinic
- assess fine cellular detail
- may give immediate diagnosis
- pre-surgical planning
what are the disadvantages of cytology?
- May not fully represent lesion
- May not exfoliate
- No tissue architecture
What can FNA be used for?
- Solid masses
- Swellings
- Organs (ultrasound guided)
- Bone marrow
What can impression smears be used to evaluate?
- Biopsies
- Organ tissues (ectomies)
- Bone marrow
What can scrapings and brushings be used to evaluate?
- Biopsies
- Firm tissue
- Corneal brush
- Oral/respiratory
- Vaginal swab
What can fluids be used to evaluate?
- Effusions
- Joints
- Urine
- TTW/BAL
- CSF
- Prostatic wash
What are your steps for FNA?
- Insert needle
- Redirect multiple times (with or w/o negative pressure)
- Withdraw (release negative pressure FIRST)
- Remove needle from syringe
- Draw back syringe
- Re-attach needle
- Expel onto slide
- Smear
Non-aspiration: FNA
- Less blood/fluid contamination
Aspiration: FNA
- Use of negative pressure while redirecting
- Firm tissue and less exfoliative lesions
Sample collection: scraping
- Flat, dry cutaneous lesions
- Surface of firm biopsies
- Superficial only, contaminants
What is Diff Quik?
- 1-2 mins, easy in clinic
- Confirm adequacy before submission
- Check 1-2 slides, submit others unstained
- May NOT stain mast cell granules
Submission and handling
- Transport in a slide carrier (not just Styrofoam)
- *extremely susceptible to formalin fumes=blurry
Approaching cytology: low power
- Adequate sample
- Cellularity (high, med, low)
- Where to look
Approaching cytology: medium power
- Uniform vs. heterogenous
- Arrangement
- Extracellular material
Approaching cytology: high power
- Cellular details (cytoplasm, nucleus)
- Granules, pigment, inclusions
- Organisms
Sample adequacy
- Actually having cells on the slide
- Have intact cells
- Thin layer
- Minimal blood
Cell features
- Cytoplasm and nuclei
- Shape, colour, texture
- Borders can be indistinct=use nuclei to help distinguish cells
Cell arrangements: cohesive clusters
- Look zippered together
- Tight edges to the cluster
- No space between cells
Cell arrangements: aggregates
- Hard to tell from cohesive in the centre: look at edges
- Loose cells, look like could fall off
Cell arrangements: individualized
- Cell border may be distinct or indistinct/wispy
Cell types (3)
- Epithelial: cohesive clusters
- Mesenchymal: aggregates
- Round or discrete: individualized
Degenerate vs. non-degenerative neutrophils
- NOT related to degenerative left shift
- Swollen nuclei
- Paler chromatin
- Segmentation less clear
- Ex. non-degenerate: crisp segments, dense chromatin: like a blood smear)
Macrophages
- Large cell
- Round/oval or kidney bean, eccentric nucleus
- Abundant cytoplasm
- Often vacuolated
- *phagocytic: pigment, RBC, WBC, organisms, foreign material
Bacteria
- Shapes: rods, cocci, filamentous (Nocardia & Actinomyces)
- Location
o Extracellular: may be contaminants
o Intracellular=septic inflammation
What are the different things used for criteria of malignancy?
- Pleomorphism: different shapes
- Anisocytosis: different sizes
- Anisokaryosis: different nuclei sizes
- High N:C ratio
- Bi/multinucleation
- Mitotic figures: atypical vs. typical
- Prominent/multiple nucleoli
- Angular or macronuclei
- Nuclear molding
Bacteria
Fungal Hyphae
Yeast
