SA Cytology

Question 1

Why may a cytology slide be of poor quality?

Answer 1

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)

Question 2

Give some examples of artefacts you may see on cytology slides

Answer 2

Formalin exposure
Freezing
Stain precipitate 
Serum activator 
Understaining
Ultrasound gel

Question 3

If you perform a cytology on an animal with peritonitis with bacteria, what should you suspect?

Answer 3

Rupture from GI tract

Question 4

What are the limitations of cytology?

Answer 4

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)

Question 5

Which stain can you use to look for nuclear remnants when looking for reticulocytes?

Answer 5

New Methylene Blue

Question 6

What are the 2 types of reticulocytes in cats?

Answer 6

Punctate (stay in circulation for 10 days)

Aggregate (only in circulation for 24 hours so look for these when looking for reticulocytes in cats)

Question 7

How do mast cells look on cytology?

Answer 7

Very purple and granular

Question 8

How do you do a platelet count?

Answer 8

Count number of platelets in 10 high power fields, take an average, multiply by 15

Question 9

Give 2 causes of increased central pallor of RBCs

Answer 9

Myelosuppression, sepsis

Question 10

How do you do a saline agglutination test?

Answer 10

1 drop of blood, 4-5 drops of saline -> will disperse rouleaux formation but not agglutination

Question 11

How would you recognise IMHA on cytology?

Answer 11

Spherocytes, can see ghost cells, regenerative anaemia (anisocytosis, polychromasia), leucocytosis, left shift neutrophilia

Question 12

How do you distinguish monocytes from band neutrophils?

Answer 12

Monocytes: vacuolated cytoplasm

Band neutrophils: more of a C shape

Question 13

What is a metamyelocyte?

Answer 13

Early neutrophil (earlier than bands)

Question 14

How do you classify leucopenia and leucocytosis on a high power field?

Answer 14

Leucopenia: <2 leucocytes
Leucocytosis: >5 leucocytes

Question 15

How do you recognise epithelial cell tumours on cytology?

Answer 15

Clusters of polygonal cells

Question 16

How do you recognise round cell tumours on cytology?

Answer 16

Diffuse sheets of round cells

Question 17

How do you recognise mesenchymal tumours on cytology?

Answer 17

Streams/whirls of spindloid cells

Question 18

What is anisiokaryosis?

Answer 18

Different-sized nuclei

Question 19

What is karyomegaly?

Answer 19

Enlarged nucleus

Question 20

Give some cellular features of malignancy

Answer 20

Minimum of 3 must be present for malignancy: 
Hypercellularity
Pleomorphism
Multinucleation
Karyomegaly (enlarged nucleus)
Mitoses
Nuclear molding (rapid cell growth)
Coarse nuclear chromatin pattern
Large, angular or variable nucleoli

Question 21

Cholesterol crystals are frequent in which lesions?

Answer 21

Cystic lesions

Question 22

Hair follicle tumours are identical cytologically to what?

Answer 22

Follicular cysts

Question 23

How would you identify a trichoblastoma cytologically?

Answer 23

Scant amount of cytoplasm (which may be pigmented)
May be abundant pink matrix
Frequent mitoses

Question 24

Give some examples of soft tissue sarcomas in dogs and cats

Answer 24

Dogs: haemangiopericytoma, peripheral nerve sheath tumour, fibrosarcoma
Cats: fibrosarcoma, injection site sarcoma

Question 25

Give some round cell tumours of the skin

Answer 25

Histiocytoma (dome-shaped, alopecic, may be ulcerated)
Mast cell tumour
Plasma cell tumour
Cutaneous lymphoma
Histiocytic sarcoma