Histopathology 3- Cytopathology Flashcards
Name some examples of Gynaecological Cytopathology
NHS CSP smears
Diagnostic (symptomatic) smears and endometrial sampling
Name some examples of Non-Gynaecological Cytopathology
Cytopathology
Exfoliative (serous effusion, joint, respiratory, GI, CSF)
Aspiration (lymph node, salivary gland, skin and soft tissue masses, cysts, breast, thyroid…)
What is a serous membrane?
Connective tissue lined by mesothelial cells
When is a serous effusion pathological?
Always
Give some examples of serous membranes
Pericardium, Pleura, Abdominal Cavity, Tunica Vaginalis of testis
Describe how a serous effusion is formed
Serous membranes well supplied with capillaries - High fluid turnover (up to 10 litres/day)
Formation
- Hydrostatic pressure in capillaries
- Oncotic pressure (albumin)
- Vascular permeability
Resorption - Via lymphatics, capillaries and venules
Describe transudative effusions
Plasma ultrafiltrate
‘Mechanical’ –Increased Hydrostatic and decreased Oncotic
Clear, pale yellow, low protein (<3g/dL), doesn’t clot
Single bland degenerate mesothelial cells and a few macrophages and lymphocytes
Usually Benign
List some causes of transudates
Cardiac, Cirrhosis, Nephrotic, Hypoproteinemia
Describe exudative effusions
- Unfiltered plasma
- Changes in vascular permeability
- Cloudy, yellow or bloody, high protein (>3g/dL), clots
- Many cells with proteinaceous background
- Inflammation (infection, infarction, autoimmune)
- May be malignant
What are mesothelial cells?
Mesothelial cells form a monolayer (mesothelium) lining the serosal cavities (pleural, pericardial and peritoneal) and the organs contained within these cavities.
What cells are found in effusions?
Mesothelial Macrophages Lymphocytes Eosinophils Neutrophils Plasma Cells Strangers
Describe mesothelial cells in effusions
Mesodermal epithelium Microvilli Single and grouped Clusters, balls, papillae, cell-in-cell, indian files Vary in size Lacy edges Windows Molding Variable nuclear number, size, N:C ratio Perinuclear cytoplasmic density Peripheral lacy border
Describe macrophages in effusions
Usually present Can be difficult to separate from mesothelial cells (esp. degenerate) Usually single or in loose aggregates Foamy pale cytoplasm Eccentric bean shaped nucleus Lack molding, windows
Describe lymphocytes in effusions
Usually a few present
More frequent in longstanding effusions
May be a range of maturation
Lymphocytic effusions are associated with obstructed circulation through lymph nodes and associated with tuberculosis and lymphoma
-part of chronic inflammatory process
Describe neutrophils in effusions
Often find a few
If non-infectious may be well preserved
If infectious then often degenerate
If masses then usually benign
What is an LE cells?
Where are they commonly found?
A neutrophil or macrophage with an engulfed/phagocytised nucleus
Seen in lupus and AI conditions
Describe the malignant cell nuclei?
Enlarged
Increased N:C ratio
Irregular membranes
Inclusions
Coarse Irregular
Chromatin
Describe the malignant cell cytoplasm?
Various vacuoles
Mucin diagnostic (normal cells do not produce mucin therefore it is diagnositic)
Melanin
Keratinisation
Malignant mesothelioma
Primary malignancy is the context of serous effusions
Asbestos associated
Why is fine needle aspiration good for patients? [5]
- Minimal pain and post procedural discomfort
- Anaesthesia requirement minimal
- Outpatient procedure
- Saves time and hospital admission
- Rapid result
Why is FNA good for clinical management?
- Easily repeated allowing sampling of several areas with minimal trauma
- Minimal disturbance of tissue planes
Confirms malignancy leaving lesion intact - May be therapeutic for cysts and abscesses
- Quick feedback enables planning of other
- investigations
Monitor therapy by repeated sampling
Should you air dry of fix the cytology example?
Air dry or alcohol fix them
Formalin destroys all formalin so never [only used in human tissue]
Why is FNA good for the pathologist?
- Equipment simple and cheap
- Excellent cell preservation due to rapid fixation
- Fresh tissue available eg for microbiology or genetic analysis
What is granuloma?
collection of activated epitheloid histiocytes
What are the limitations of FNA?
Focality and sampling error
What is required for lung cancer diagnosis?
Adequate aspirate
Morphologic diagnosis
Immunophenotypic confirmation
Material to permit molecular genetic evaluation (EGFR/ALK)
Small cell v non small cell carcinoma
Squamous cell carcinoma v adenocarcinoma
Name a marker of lung adenocarcinoma
Napsin positive p63 negative
highly specific of lung adenocarcinoma
Name a marker of squamous cell carcinoma of the lung
p63 positive
