Flashcards in SA Cytology Deck (25)
Why may a cytology slide be of poor quality?
Ruptured cells (incorrect sampling/smearing technique)
Layer of cells too thick
Inadequate staining (insufficient time, inadequate drying prior to staining, too close to histology pot -> leakage)
Give some examples of artefacts you may see on cytology slides
If you perform a cytology on an animal with peritonitis with bacteria, what should you suspect?
Rupture from GI tract
What are the limitations of cytology?
No information about tissue architecture
Are you really sampling the lesion?
Often can't determine specific tumor type or grade for behaviour/prognosis
Limited amount of specimen (compared to a surgical biopsy)
Which stain can you use to look for nuclear remnants when looking for reticulocytes?
New Methylene Blue
What are the 2 types of reticulocytes in cats?
Punctate (stay in circulation for 10 days)
Aggregate (only in circulation for 24 hours so look for these when looking for reticulocytes in cats)
How do mast cells look on cytology?
Very purple and granular
How do you do a platelet count?
Count number of platelets in 10 high power fields, take an average, multiply by 15
Give 2 causes of increased central pallor of RBCs
How do you do a saline agglutination test?
1 drop of blood, 4-5 drops of saline -> will disperse rouleaux formation but not agglutination
How would you recognise IMHA on cytology?
Spherocytes, can see ghost cells, regenerative anaemia (anisocytosis, polychromasia), leucocytosis, left shift neutrophilia
How do you distinguish monocytes from band neutrophils?
Monocytes: vacuolated cytoplasm
Band neutrophils: more of a C shape
What is a metamyelocyte?
Early neutrophil (earlier than bands)
How do you classify leucopenia and leucocytosis on a high power field?
Leucopenia: <2 leucocytes
Leucocytosis: >5 leucocytes
How do you recognise epithelial cell tumours on cytology?
Clusters of polygonal cells
How do you recognise round cell tumours on cytology?
Diffuse sheets of round cells
How do you recognise mesenchymal tumours on cytology?
Streams/whirls of spindloid cells
What is anisiokaryosis?
What is karyomegaly?
Give some cellular features of malignancy
Minimum of 3 must be present for malignancy:
Karyomegaly (enlarged nucleus)
Nuclear molding (rapid cell growth)
Coarse nuclear chromatin pattern
Large, angular or variable nucleoli
Cholesterol crystals are frequent in which lesions?
Hair follicle tumours are identical cytologically to what?
How would you identify a trichoblastoma cytologically?
Scant amount of cytoplasm (which may be pigmented)
May be abundant pink matrix
Give some examples of soft tissue sarcomas in dogs and cats
Dogs: haemangiopericytoma, peripheral nerve sheath tumour, fibrosarcoma
Cats: fibrosarcoma, injection site sarcoma