L1: Intro To Cytology In Vet Practice Flashcards
Cytopathology =
The study of CELLULAR disease and the use of cellular changes for the diagnosis of disease
Meeting cytology goals relies on:
- nature and distribution of lesion
- proper collection technique, slide prep, and staining
- skill/experience of the cytologist
Considerations prior to sample collection:
- signalment
- presence of inflammation/infection and/or infection (avoid!)
- exfoliation of lesion (low cellularity, presence of significant blood)
- platelet function and coagulation
- clinical diagnosis
Boxers prone to mast cell tumors
:(
Advantage of cytology over histo
- easier to collect
- less discomfort
- less likely to result in serious complications
- costs less
- faster turn around time
Advantages of histo over cytology
- gold standard b/c more tissue architecture present
- better for poorly exfoliative lesions
- more definitive diagnosis (preserves tissue architecture, and can differentiate b/w inflammatory and neoplastic changes)
How can inflammatory slide look neoplastic artificially?
neutrophils release myeloperoxidase on top of normal cells, making them look ugly and neoplastic
Cases in which cytology not the best:
- low cellularity or hemodilute sample
- thick preparation
- not representative of lesion
- rough handling
- mixed cell populations
- lesions requiring tissue architecture
- mammary tissue
Cytology may be used in 2 ways:
Diagnosis
Screening
Types of cytology samples
- fluid samples
- tissue aspirates
- tissue scrapings
- tissue imprints
General indications for the use of diagnostic cytology
- effusions
- urine sediments
- prostate (direct aspirate, washing)
- lymphadenopathy
- exam. Of metastatic disease
- diffuse organomegaly
- cutaneous/subcutaneous mass/lesion
- conjunctival/vitreous/aqueous cytology
- pulmonary/nasal aspirates/brushings
- bronchoalveolar/nasal washing/lavage
- abd. Mass
- intraoperative mass or lesion
Anything in formalin is histopath!!
:)
“Cytology kit” collection supplies
- 22-25 g needles
- 3-6 mL syringes
- glass slides w/ frosted edge
- pencil
- scalpel blade
- fluid samples: purple top for cytology, red top for culture***
- don’t put urine in red tops - silica can interfere with sediment
Sample handling of fluids
- made glass slide at time of collection**
- refrigerate fluid sample (not slides)
- process ASAP to preserve cell counts/morphology
- special requirements for BAL and CSFs
2 tissue aspiration techniques
Needle attached or not attached to syringe. Attached better for larger masses, masses that are difficult to exfoliate, or cutaneous/SC masses. Needle w/o attached syringe allows for better control w/ smaller masses, is less traumatic, and good for masses in all layers including intra-abdominal
