Introduction to Cytology

What is cytology?

Microscopic evaluation of cells on a glass slide

What are examples of sample types?

• needle aspirate of solid tissue

  • Skin masses

  • Spleen, liver, abdominal organs

  • Lymph nodes

  • Etc

• Fluids

  • Body cavity effusion

  • Synovial fluid

  • Fluid from a cyst, abscess, or fluid filled mass

  • Fluid from an organ

What is the name of the collection method for collecting a sample with a needle from solid tissues?

Fine needle aspirate

What is the difference between cytology and histopathology?

Cytology: taken via aspiration and smeared onto a slide, interpreted without architecture to determine type not arrangement

Histopathology: tissue biopsy samples, preserves architecture to be evaluated as a whole

What are advantages to cytology?

• quicker sample collection time

• Minimally invasive

• Lower cost

• Requires no - mild sedation

• Can be performed on fluids

What are some disadvantages to cytology?

• some tissues are poorly-exfoliative (non diagnostic sample)

• Some tumor types cannot be diagnosed without architecture

• Good technique is critical to good sample

• Cells scattered randomly - no architecture

What is a pre analytical error?

Errors that occur prior to analysis

• in sample collection or processing

List examples of pre analytical error.

• poor technique for sample collection

• Poor spreading technique on the slide

• Mistakes in sample fixation

• Poor staining

• Poor clinical history provided for patient

What size needle is needed for FNA?

21 or 22

What type of sample collection would require a scalpel blade?

Impression smear of a skin scrape

True or False: a viscous fluid would require a 21g needle and a less viscous fluid would require a 22g

TRUE

What are the two preferred methods of smearing technique?

• horizontal pull apart / squash prep (BEST)

• Blood smear technique

What smearing techniques are not preferred?

• starfish

• Vertical pull apart

• Not smearing at all

What can you feel while performing the smear technique that can indicate the cells ruptured?

Suction effect

How do you perform an impression smear?

Take gauze and gently dab excess blood from the surface and then Gentilly tap the glass slide to the surface of the tissue being collected

How many slides should you prepare?

3-6 but need AT LEAST 2-3 (temperament dependent)

Do you have to stain all the slides before sending them to the lab?

no stain 1-2 to ensure you have a good samoke

Prior to fixation, smears should be allowed to:

Air dry at room temperature

What is used for fixation?

100% methanol

What should be avoided during fixation?

• don’t heat fix

• Avoid formalin fumes

  • Don’t sit next to formalin

  • Don’t ship with formalin sample

What happens to the sample if there is formalin exposure?

• all cells stain very blue and loss of cell detail

When should stain be thrown away?

6 months

Which stain ages faster and requires more dips?

Blue stains

List some examples of Romanowski type stains.

• wrights

• Wrights leishman

• Wrights giemsa

• Giemsa

• Quick wrights

• Diff quik

A we,l prepared smear will have cells that are

Flattened to see the nucleus and cytoplasm

What are the two main types of cells found?

Inflammatory and tissue type cells

List the inflammatory cells.

• neutrophils

• Macrophages

• Eosinophils

• Lymphocytes and plasma cells

List the tissue type cells.

• epithelial

• Messnchymal

• Discrete round cell