Topic 7: Cytology

Question 1

Cytology is the study of what?

Answer 1

Cells

Involves the collection and examination of cells and fluid from the body surfaces, cavities and tissues.

Question 2

What is aspiration cytology?

Answer 2

Collecting samples within the body by use of needles and syringes

Question 3

What are the basic purposed of cytology exams?

Answer 3

Characterise any type of fluid or cells present and to determine the presence or absence of inflammation or neoplasia

Question 4

What is the peritoneal cavity and can fluid be aspirated from here?

Answer 4

the two membranes that separate the organs in the abdominal cavity from the abdominal wall.

Yes in clinically healthy horses and cattle.
Not normally in dogs and cats

Question 5

How may cytology specimens from the skin be collected?

Answer 5

Skin scrapings or direct impressions

Question 6

How are cells from the MMs of the digestive, resp or repro system collecteD?

Answer 6

With a sterile swab or by washing the area with fluids that are reaspirated

Question 7

What is direct needle aspiration used for?

Answer 7

Joints
Body cavities
Spinal column
Abnormal subcutaenous swellings

Question 8

Cytology sample collection can be performed under the guidance of what?

Answer 8

Fluroscopy
Ultrasound - most favoured
Computed tomography

Question 9

What is abdominal paracentesis?

Answer 9

Collection of needle aspirant samples from the abdo cavity
In cases of:
- excessive fluid accumulation
- acute abdo pain with potential haemarrage or rupture of internal organs
- suspected presence of abnormal cells

Question 10

How is abdominal paracentesis performed?

Answer 10

Animal should be standing to allow fluids to collect ventrally
Puncture site may be in the lowest point of the abdo profile between the xiphoid cartilidge and umbilicus
Collection slightly to the right of the midline will help avoid spleen and liver
22-18 g needle through skin, muscle and peritoneum at an angle with the bevel downward to prevent blockage of the needle by omentum
Slides made directly from sample of centrifuged and sediment used

Question 11

What tube should you place body cavity fluid in?

Answer 11

EDTA - cell features better maintained and bacterial proliferation is inhibited

Question 12

When collecting fluid from the thorax, where should you place the needle?

Answer 12

Between the ribs using a 20-16g needle

Question 13

Some things to remember when doing fine aspiration on a joint?

Answer 13

Sterility is essential
16-18g needle
FLexion of the joint

Question 14

What is transtrachael aspiration?

Answer 14

Cytology or culture samples from the lower resp tract

Question 15

What are the general categories of cytological interpretation?

Answer 15

Non-diagnostic 
Inflammation 
No cytologic abnormalities 
Hyperplasia/dysplasia 
Neoplasia

Question 16

What are some reasons for obtaining a non-diagnostic sample?

Answer 16

• Poor cellularity of the sample
• Excessive blood contamination
• Many smudged or ruptured cells
• Sampling error

Question 17

What are inflammatory responses classified as?

Answer 17

• Suppurative: >85% neutrophils, suspect immune-mediated, sterile irritants, neoplastic lesions
• Histiocyte/macrophagic: macrophages predominate, suspect foreign body, fungal or bacterial infection
• Mixed: neutrophils and macrophages lymphocytes and plasma cells, suspect chronic tissue injury
• Eosinphilic: >10-20% eosinphils, suspect hypersensitivity/allergic condition, parasitic disease, fungal infection
• Lymphocytic or lymphoplasmacytic: suspect antigenic/immune stimulation, early viral infections or chronic inflammation

Question 18

If aspirant is inflammatory what should you do next?

Answer 18

Check for presence of bacteria or other microorganisms

Question 19

What is hyperplasia?

Answer 19

Increase in the number of cells in a tissue OR non neoplasia enlargement of a tissue

Often the reult of hormonal influences, tissue injury or antigenic stimulation

Question 20

What is dyplasia?

Answer 20

Disordered growth
Often seen in epithelial tissue secondary to inflammtion or irritation

Results in loss of uniformity of the individual cells

Can be difficult to distinguish between neoplasia

Question 21

When is neoplasia suspected?

Answer 21

When an atypical cell population is present particularly is an inflammatory response is lacking

Question 22

Normal joint fluid is what?

Answer 22

Viscous and of low cellularity

50-90% mononuclear cells