PATHOLOGY - Cytology Flashcards
(54 cards)
What are the indicators for cytology?
Skin and subcutaneous masses
Lymphadenopathy (enlarged lymph nodes)
Intra-thoracic masses
Intra-abdominal masses
Body cavity effusions
Urine sedimentation
Traumatic catheterisation
Prostatic wash
Bronchoalveolar lavage
Bone marrow sampling
What is traumatic catheterisation?
Traumatic catheterisation is often done when you suspect bladder neoplasia, and involves wedging the urinary catheter into the tissue and aspirating a sample
What are the two techniques that can be used to take cytology samples?
Non-aspiration
Aspiration
How do you carry out non-aspiration cytology sampling?
Hold a 23g needle in one hand and fix the mass with the other hand. Insert the needle into the mass and redirect it 3 to 4 times. Only expect to see very little or nothing in the needle hub. Connect the needle to a 5 to 10ml syringe with 5 to 10mls of air drawn into it and expel the contents on a slide. Label your sample and stain to examine in house or send unstained smears to the lab
Which stain is typically used for cytology?
Modified Romanowsky stain
e.g. DiffQuick staining
How should you stain fatty cytology samples?
When staining fatty cytology samples, place the slide in the fixative stain (the first one for DiffQuick) for 5 minutes as fatty samples are more likely to slip off the slide, then proceed to stain as normal
What are the benefits of non-aspiration cytology sampling?
Minimal cell disruption
Reduces haemodilution
Good for lymph node and skin tumour sampling
Why is non-aspiration cytology sampling particularly beneficial for neoplasia?
Neoplastic cells are often more fragile than normal cells and thus non-aspiration cytology is beneficial as it causes minimal cell disruption
What are the limitations of non-aspiration cytology?
Non-aspiration cytology often does not yield a sample from mesenchymal tumours as mesenchymal cells are often well fixed
How do you carry out aspiration cytology sampling?
Hold a 23g needle connected to a 5-10ml syringe in one hand and fix the mass with the other hand. Insert the needle into the mass and aspirate the syringe once or twice. Release the suction and redirect the needle within the mass and repeat. Release the suction before removal of the needle. Disconnect the needle from the syringe, fill the syringe with air and reattach to the needle and expel the contents onto the slide. Label your sample and stain to examine in house or send unstained smears to the lab
Often done with ultrasound guidance
When is aspiration cytology sampling indicated?
Aspiration cytology sampling is often done if non-aspiration sampling does not yield a sample
What are the potential complications of cytology sampling?
Introducing infection
Haemorrhage
Pneumothorax
Tumour seeding
What are some of the causes of poor quality cytology samples?
Poor sampling technique
Intrinsic nature of the mass being sampled
Haemodilution
Dirty slides
Ultrasound gel contamination
Which mass types can result in a poor quality cytology sample?
Fibrous mass
Vascular mass
Cystic mass
Necrotic mass
What are some of the causes of poor quality cytology staining?
Sample is too thick
Ultrasound gel contamination
Heavily granulated cells
Background extracellular matrix (ECM)
What should be done to maintain the quality of cytology stains?
Keep the lids on the stains
Periodically refill the stains
Regularly filter the stains
Seperate the stains used for cytology from other uses
What is the general approach to interpreting cytology slides?
First, determine if the sample is adequate. If the sample is adequate, then determine if the sample is inflammatory or neoplastic. If the sample is inflammatory, determine the predominant inflammatory cells present. If the sample is neoplastic, determine if it is round cell, mesenchymal cell and epithelial cell and determine if it is benign or malignant
How do you determine if the cytology sample is adequate?
Assess the slide macroscopically
Assess the slide microscopically on 10x view and assess is there is enough cells, is the smear too thick or thin, are the cells intact. And assess if the staining is even and is it understained or overstained
Which questions should you ask yourself when evaluating a cytology slide?
What is the cellularity?
How are the cells distributed?
Are they inflammatory cells or tissue cells?
What is in the background? (i.e. erythrocytes, extracellular matrix, fluid etc)
What is another term for neutrophilic inflammation?
Suppurative inflammation
What is commonly associated with neutrophilic inflammation?
Acute bacterial infections
What are degenerate neutrophils?
Degenerate neutrophils are where the neutrophils are larger than normal with distended cytolasm and a slightly swollen, enlarged nucleus
Which cell types are predominant in pyogranulomatous inflammation?
Neutrophils
Macrophages
What is often indicated by pyogranulomatous inflammation?
Foreign body reaction
Fungal infection
Chronic injury
