Cytology Of The Respiratory Tract

Front 1

What special consideration should you have before sampling the nasal cavity for cytology?

Back 1

The nasal cavity bleeds ALOT! Always check clotting before taking samples.

Front 2

What indications are there for taking a nasal swab?

Back 2

Nasal swabs can be useful if there is significant nasal discharge, however, discharge is often non-specific.

Good for identifying some fungal infections such as Cryptococcosis in cats.

Front 3

What are nasal flushes good for and why must you be careful when performing one?

Back 3

Collecting cells from the nasal cavity.

Be careful not to penetrate the cribiform plate!

Front 4

What are brush cytology samples used for?

Back 4

Evaluating surface cells.

Front 5

What tube would you place a cytology sample into? A culture sample?

Back 5

EDTA tube for cytology
plain serum tube for culture

Front 6

Describe what you should see in a NORMAL nasal cytology sample.

Back 6

Low cellularity
Small amount of mucous
Low amounts of normal bacterial flora (Staph, strep, pseudomonas, proteus)

Front 7

How would you know if you had oropharyngeal contamination in your sample?

Back 7

You would see non-keratinized squamous epithelial cells with Simonsiella spp.

Simonsiella spp. look like stacks of coins.

Front 8

What cytological changes would you see with bacterial rhinitis?

Back 8

Degenerate neutrophils with intracellular bacteria, increased mucous and goblet cells, changes to the nasal epithelial cells.

Front 9

Is bacterial rhinitis usually primary or secondary?

Back 9

Usually a secondary finding to a nasal FB, neoplasia, oronasal fistulas, or dental disease.

Front 10

What are some examples of primary causes of bacterial rhinitis?

Back 10

Bordatella bronchiseptica and Pasteurella multocida in dogs

Mycoplasma spp. and Chlamydophila in cats.

Front 11

What cells are seen with fungal rhinitis and what two fungi are most common?

Back 11

Neutrophils and macrophages.

Cryptococcus sp. in cats
Aspergillus sp. in dogs and cats

*Be aware that fungi can be secondary invaders!

Front 12

What cells are seen with allergic rhinitis?

Back 12

Eosinophils!!! Also some neuts, mast calls and rarely plasma cells.

Front 13

What cells are seen in chronic rhinitis?

Back 13

Lymphocytes, plasma cells, macrophages, and fewer neutrophils.

Front 14

Why can cytology be misleading in the diagnosis of neoplasia of the nasal cavity?

Back 14

Inflammation can look like neoplasia! Try treating the inflammation and then re-sample. Or better yet, do histopath to diagnose!

Front 15

What two diagnostic tests can be used to evaluate the lung airways?

Back 15

Tracheal wash and Bronchoalveolar lavage.

Front 16

Describe the percutaneous method of Tracheal wash, including advantages and disadvantages.

Back 16

A catheter is inserted through the cricothyroid ligament and down the trachea to the level of the carina (4th intercostal space). Sterile saline is then injected until the dog coughs and the fluid is aspirated.

Advantages: Minimal oropharyngeal contamination. No GA needed for large dogs.

Front 17

Describe the ET tube method of tracheal wash, including advantages and disadvantages.

Back 17

Insert a catheter down the ET tube to the level of the carina. Inject sterile saline and then aspirate.

Advantages: Good for small dogs and cats and in animals in which an ET tube has already been placed.

Disadvantages: Increases oropharyngeal contamination and GA is required.

Front 18

Describe BAL.

Back 18

BAL is used to evaluate the lower airways. Its more effective than TW. You can do it via an ET tube or with bronchoscopy (preferred method). GA is needed.

Front 19

List what you would see in a NORMAL TW or BAL.

Back 19

Small amounts of mucous
Ciliated and non-ciliated epithelial cells
Goblet cells
Macrophages (indicated good sample)
Other less abundant cell types include: Neuts, lymphs, mast cells and eosins.

Front 20

List some causes of non-septic purulent inflammation in a TW/BAL.

Back 20

Tissue necrosis
Smoke inhalation
Neoplasia

Front 21

What are three causes of Eosinophilic inflammation in a TW/BAL?

Back 21

1. Parasitism (heartworm, lungworm)
2. Hypersensitivity (asthma in cats)
3. Hypereosinophilic syndromes

Front 22

Describe what you would see in a TW/BAL in an animal with Chronic inflammation.

Back 22

Multinucleated macrophages
Curshmann's spirals
Epithelial and goblet cell hyperplasia

Front 23

What are Curshmann's spirals and what do they indicate?

Back 23

Bronchiolar casts of mucous secondary to excessive mucous production. They indicate bronchiolar obstruction.

Front 24

In horses, what are the most common lung pathogens (bacterial and fungal)?

Back 24

Strep zooepidemicus, other strep spp., Rhodococcus equi, Cryptococcus and Aspergillus.

Front 25

What cytological findings would you find in a horse with recurrent airway obstruction?

Back 25

Mixed neutrophils and macrophages
Curshmann's spirals
Hyperplastic respiratory epithelium

*The findings are not specific! They just show chronic inflammation.

Front 26

What would you find in a TW/BAL from a horse with exercise induced pulmonary heamorrhage?

Back 26

Blood
Macrophages
Erythrophagia
Hemosiderin

Front 27

What would you find in a TW/BAL from a horse with pulmonary neoplasia?

Back 27

Neoplasia is not readily diagnosed with TW or BAL because most lung tumours are interstitial and may not invade the airways!