importance and role of fine needle sampling Flashcards
Define cytology
the study of cell number and type in a tissue mass or fluid accumulation, to investigate its cause
Give examples of common cytological specimens
Fine needle samples:
- Capillary action sample
- Aspirate
Touch imprints
Body fluids
Lavages
What are the different types of fine needle sampling and what is the difference between them?
FNCS (fine needle capillary sample):
- With no suction
– no syringe attached
- preferred
FNA (fine needle aspiration):
- With minimal suction
– cysts or failed FNCS
What are the uses of diagnostic cytology?
Differentiation of inflammation from tissue growth
Differentiation of types of inflammation
Detect neoplasia:
- malignant vs benign
- type
Differentiation of fluids
What are the advantages of cytological sampling?
Quick
Safe
Inexpensive
Cells can often be safely retrieved from lesions near vulnerable structures in conscious animals, making anaesthesia & surgical biopsy unnecessary.
Sampling demands little equipment or skill
Results can be quickly available
What are the limitation of cytology
False negatives and false positives in the detection of neoplasia
What can cause false negatives in cytological detection of neoplasia?
Poor exfoliation of a neoplasm
Failure to sample tumour tissue
Extensive necrosis/inflammation present
What can cause false positives in cytological detection of neoplasia?
Dysplasia (which can mimic neoplasia) may occur in inflammatory diseases
Inflammatory dysplasia: proliferative changes and atypical morphology in some cells (eg mesothelial cells) caused by inflammation/irritation
Compare fine needle sampling with biopsies
What are the different types of inflammation?
What are the different types of cystic lesion?
What are the different types of neoplastic lesion?
Describe epithelial neoplasia cells
High yield, cells associated with one another, rafts, sheets, acini, cuboidal, columnar
Describe spindle/mesenchymal neoplasia cells
Low yield, spindle shaped cells, usually single but may be in association/sheets, may be “matrix”
Describe round neoplasia cells
High yield, discrete round cells, not adherent
