Module 6 - Diagnostic Cytology

Question 1

What is Diagnostic Cytology?

Answer 1

The interpretation of cellular changes related to benign, inflammatory and neoplastic conditions
Assessment of single cells or cell aggregates without the typical architectural landmarks that are otherwise observed in histopathology sections

Question 2

Examples of How to Get Samples

Answer 2

Exfoliative cells in spaces:
- fluids e.g. CSF, urine
- secretions e.g. sputum
Abrasive - mechanical assistance:
- scraping/brushing e.g. FGT
Fine needle aspirations
- superficial - thyroid, breast, skin
- deep - lung, pancreas, liver

Question 3

Advantages of Cell Block (CB)

Answer 3

Maintain architecture which most closely resembles the specimen
Stored indefinitely for future dx and research purposes

Question 4

Methods for CB

Answer 4

Plasma thrombin method (most common in WA)
Clot and scrape method
BBC cell block fixative
HistoGel
Shandon Cytoblock method
Etc.

Question 5

Plasma Thrombin Method

Answer 5

1. Cell suspension is centrifuged
2. The supernatant is aspirated and the cell deposit is mixed with plasma
3. Thrombin is added and mixed
4. The clot that forms is given time to retract
5. Add NBF to the clot/transfer clot to NBF for subsequent processing and sectioning

Question 6

Fixation

Answer 6

Alcohol - coagulative fixatives

• 95% ethanol
• acetic alcohol 3% acetic acid and 95% ethanol
• spray fixatives (combination of isopropanol and water soluble wax)

Question 7

Cytopreparation

Answer 7

Lab methods and safe handling of biohazardous samples
Preparation of cell samples for microscopy from the range of gynaecological and non-gynaecological specimens
Recognition of unsatisfactory samples/preparations and artefacts

Question 8

Fixed Slide Staining for Cytopathology

Answer 8

Wet fixed smears are stained using Papanicolaou technique

Differential stain allows easy distinction between cells based on pH of cytoplasm

Question 9

Air Dried Staining for Cytopathology

Answer 9

To rehydrate smears for Pap staining, immerse slides in saline or 50:50 gylceral:DW and post fix in 95% EtOH

Question 10

Advantages and Disadvantages of Diagnostic Cytopathology

Answer 10

Advantages:
- rapid
- relatively non-invasive
- low complication risk
- accurate
- inexpensive
Disadvantages:
- less information than biopsy
- adequate sampling can be problematic

Question 11

General Principles of Microscopy

Answer 11

Normal vs departure from normal
Criteria:
1. Background of smear
2. Cellular arrangements
3. Nuclear criteria
- enlarged
- hyper/hypochromic
- irregular nuclear membrane
- prominent nucleoli
4. Cytoplasmic features
- vacuoles
- mucins
- dense or delicate

Question 12

General Principles of Microscopy - Evaluating the Cell

Answer 12

Nucleus reflects the activity of the cell

Cytoplasm reflects the function of the cell