pathology 13 - intro to cytology Flashcards
what are fluid samples assessed for?
gross appearance, total cell count, total protein, cytology, differential cell count.
what is cytology?
examination and assessment of cells.
what does BAL and TTW stand for? which other fluids may you collect? what do you submit them in?
Bal - bronchoalveolar lavage
ttw - transtracheal wash
pleural, peritoneal, synovial fluid
submit in EDTA tube (cyto and cell count) as well as sterile tube (biochem)
if posting make smears too. preservation done using cytospin collection fluid 50:50.
what must you do to every sample you ever submit?
label it!!!!!!!!
urine samples submitted in?
what other test can you do for urine.?
what does wet prep refer to?
if you need to look at abnormal cells/inflammation then what should you use?
urine - sterile container for routine, EDTA for cytology (with an anticoagulent)
can also do dip stick test for urine. (uncentrifuged)
wet prep can done for rbc, wbc, crystals, bacteria, fa droplets
if want to look for abnormal cells then do a dried smear from EDTA sample. (cytospin fluid added to preserve.)
ways to get sample to smear? (4) what should you not do if collecting from a lymph node with FNA?
- ti
- scraping
- FNA
- swab
- touch imprints - impression smears. rapid diagnosis - yeild few cells, use a fresh surface and blot first to remove excess blood then gentle multiple impressions on a slide.
- scrapings - collects more cells, goo for parasitology, use a scalpel (blunt) perpendicular to surface.
- fine needle aspirates - FNAS - cutaneous masses, lymph nodes, organs, avoids superficial contamination and collects samples from deep. risks of missing a small lesion.
- shouldn’t apply suction to a lymph node!! - needle only - swabs - good for hard to reach tissues eg. vagina. moisten in 0.9% nacl. roll swab over slide after.
techniques for smear preparation. depends on what?
viscosity of sample and presence of particles.
2 techniques for smear prep:?
- squash preparation - FNAS , viscous samples, bone marrow - sample placed in middle of slide and spreading slide placed on top. move to slides apart parallel or a right angle to spread sample.
- blood smear tech: blood smears , high cellularity fluid, fnas, samples centrifuged. - sample placed at one end of slide, spread brought into contact and moved toward one end - produces feathered edge.
3 main stains used for cytology?
Diff - Quik - general
gram stain - bacteria
ZN - acid fast bacteria inside cells - red.
What is the diff-quik stain used for?
haematology /cytology. does not stain some granules well. easier to examine if use cover slip. and DPX mounting fluid. let it dry on.
what is the general approach to assessing cytology slides? (4 steps)
- low power to look over for large structures eg. artefacts, clusters and parasites - orientate yourself
- x20 or x40 - look more closely at areas of interest
- place a drop of oil on slide x100 and get a more detailed look at cell.
- look ALL over the smear!!
what is the logical approach to cytological interp?
- types of cells
- degree of abnormaility
- nature of processes present
cell types? 3 categories? eg’s?
- epithelial - squamous, basal, glandular/duct
- mesenchymal - ct-fibroblasts, osteoblasts
- round cells -lymphocytes, plasma cells, mast cells.
what may be the processes present? - normal/hyperplastic tissue?
normal/near normal cells. benign prostatic hyperplasia - may be mild changes eg. slightly variable nucleus:cytoplasm ratio (c:n ratio)
may see a cyst? what would you see?
contain fluis and few cells. eg. sweat gland cyst. low protien - pale pink. low number of cells. marcophages dominate. evidnece of haemorrhage. may see fibroblasts (mesenchymal cells)
