Lecture 34 Flashcards
What is Cytology?
* Examining _____ (usually from a _____ or _____ sample) under a microscope
o Normal or hyperplastic
o Inflammatory
o Neoplastic
o Infectious organisms!
What is Cytology?
* Examining cells (usually from a mass or fluid sample) under a microscope
o Normal or hyperplastic
o Inflammatory
o Neoplastic
o Infectious organisms!
Sample Types for Cytology
* ____-needle aspiration and ______ smear; tissue imprints
o E.g?
* Washes
o E.g.?
* Fluids
o E.g.?
Sample Types for Cytology
* Fine-needle aspiration and impression smear; tissue imprints
o FNA: Typically 22G needle and 5cc syringe
* Washes
o Prostatic, transtracheal, etc.
* Fluids
o Peritoneal, pericardial, pleural, synovial
o Cerebrospinal fluid, bronchoalveolar lavage
o Urine
What are the pros of Cytology?
PROS
* Minimally invasive
* Fast, simple, inexpensive
* Relatively simple
* Better cellular detail than
histopathology
* Infectious organisms
What are the cons of Cytology?
CONS
* Cannot evaluate tissue architecture
* Poorly exfoliating lesions
o Some sarcomas (more mesenchymal)
* Ruptured cells
* Can’t always make a
diagnosis
* Sometimes difficult to differentiate reactive mesenchymal cells from neoplastic cells
Components of Cytologic Evaluation
* **Best to send organ aspirates and bone marrows for pathologist evaluation - do not try to interpret
* Overall cellularity
- High vs. low
- Low cellularity samples make interpretation difficult to
impossible
* Cell components/types
- Uniform population: normal, hyperplastic or neoplastic
- Mixed: inflammatory, or neoplasia with inflammation
* Background components
o Blood, proteinaceous material, organisms
Components of Cytologic Evaluation
* **Best to send organ aspirates and bone marrows for pathologist evaluation - do not try to interpret
* Overall cellularity
- High vs. low
- Low cellularity samples make interpretation difficult to
impossible
* Cell components/types
- Uniform population: normal, hyperplastic or neoplastic
- Mixed: inflammatory, or neoplasia with inflammation
* Background components
o Blood, proteinaceous material, organisms
Cytology Basics
* Scan the slide at low magnification (10x)
* Find cellular areas where cells are well spread out and intact
o Can evaluate appearance of nucleus and cytoplasm of individual cells
Cytology Basics
* Scan the slide at low magnification (10x)
* Find cellular areas where cells are well spread out
and intact
o Can evaluate appearance of nucleus and cytoplasm of
individual cells
have to use 40x
Cell structure = immersion oil under 100x
Must tell person you are sending it to where the sample was obtained from.
What questions do you ask yourself if inflammatory? Non-inflammatory?
xx
Inflammatory Cell Types?
o Neutrophils
o Eosinophils
o Lymphocytes
o Macrophages
o Plasma cells
o Mast cells
Classification of
Inflammatory Lesions IMPORTANT
* Suppurative inflammation =
* Mononuclear =
* Histiocytic/Granulomatous =
* Pyogranulomatous =
* Eosinophilic =
* Lymphoplasmacytic =
* Mixed =
- Suppurative/neutrophilic - neutrophils
- Mononuclear - lymphocytes, plasma cells or macrophages
- Histiocytic/Granulomatous
- Macrophages
- Pyogranulomatous
- Neutrophils + macrophages
- Eosinophilic = eosinophils
- Lymphoplasmacytic
- Mixed = Any combination of cells
Suppurative Inflammation
* >70% of inflammatory cells are _______
* Evaluate ______ morphology
o Degenerate or non-degenerate?
o If degenerate, go on a bug hunt!
Suppurative Inflammation
* >70% of inflammatory cells are neutrophils
* Evaluate neutrophil morphology
o Degenerate or non-degenerate?
o If degenerate, go on a bug hunt!
Neutrophil
Causes of Suppurative
Inflammation: Infectious
* Bacterial infection
o Suspect this if _______ neutrophils are present!!!
o (Even if you see no _______)
o Termed ____ suppurative if ______ are seen
* Suppurative + eosinophilic component
o Suggests ____ or _____ component to inflammatory response
Causes of Suppurative
Inflammation: Infectious
* Bacterial infection
o Suspect this if degenerate neutrophils are present!!!
o (Even if you see no bacteria)
o Termed septic suppurative if bacteria are seen
* Suppurative + eosinophilic component
o Suggests parasitic or allergic component to inflammatory
response
Causes of Suppurative
Inflammation: Non-Infectious
- Severe irritant/chemical
o Example: uroperitoneum, bile peritonitis - Immune-mediated inflammation
- Trauma
- Ruptured follicular/epidermal cysts
Histiocytic/Granulomatous Inflammation
* >50% ______
* Causes: infectious
1. Protozoal infection (e.g. Leishmania, Toxoplasma spp.)
2. Atypical bacteria (Mycobacteria, Nocardia, Actinomyces spp.)
3. Fungal infection
* Suspect this especially if epithelioid
macrophages +/- multinucleated giant
cells are found!
* Histoplasma, Blastomyces, Cryptococcus,
Coccidioides spp.
Histiocytic/Granulomatous Inflammation
* >50% macrophages
* Causes: infectious
o Protozoal infection (e.g. Leishmania,
Toxoplasma spp.)
o Atypical bacteria (Mycobacteria, Nocardia,
Actinomyces spp.)
o Fungal infection
* Suspect this especially if epithelioid
macrophages +/- multinucleated giant
cells are found!
* Histoplasma, Blastomyces, Cryptococcus,
Coccidioides spp.
Histiocytic/Granulomatous Inflammation
* Causes: non-infectious
- Foreign body or foreign material
* Plants (grass awns)
* Vaccine adjuvant - Acral lick dermatitis/lick granuloma
- Late stage of chronic/resolving inflammation
Pyogranulomatous Inflammation
* 50-70% __________
* 30-50% _________ cells = ?
–> Causes
1. Foreign body or fungal infection
* Suspect this especially if epithelioid macrophages +/- multinucleated giant cells are found!
2. Chronic/resolving suppurative
inflammation
Pyogranulomatous Inflammation
* 50-70% neutrophils
* 30-50% mononuclear cells
o Macrophages, multinucleated giant cells, lymphocytes, plasma cells, mast cells
* Causes
o Foreign body or fungal infection
* Suspect this especially if epithelioid macrophages +/- multinucleated giant cells are found!
o Chronic/resolving suppurative
inflammation
Eosinophilic Inflammation
* > 12% eosinophils
* Causes: infectious
o Parasites
* Dracunculiasis, demodicosis, dirofilaria, dermatophytes
o Oomycosis and algal organisms
* Pythium, Prototheca (seen in sheep, goats, and dogs)
* Causes: non-infectious
o *May see increased numbers of mast cells and/or basophils, too
o Eosinophilic plaque/granuloma induces eosinophilic inflammation. Commonly seen in cats, and sometimes dogs IMPORTANT
o Flea bite allergy/food allergy/atopy (eosinophilic inflammation on site).
o Arthropod bite reaction
Eosinophilic Inflammation
* > 12% eosinophils
* Causes: infectious
o Parasites
* Dracunculiasis, demodicosis, dirofilaria, dermatophytes
o Oomycosis and algal organisms
* Pythium, Prototheca (seen in sheep, goats, and dogs)
* Causes: non-infectious
o *May see increased numbers of mast cells and/or basophils, too
o Eosinophilic plaque/granuloma
o Flea bite allergy/food allergy/atopy
o Arthropod bite reaction
Neoplasia
* 3 general categories: ?
o **Remember to scan at low magnification (____x) first to
assess cell distribution
o Need to evaluate cytologic criteria of malignancy to determine benign vs. malignant - for epithelial or mesenchymal tumors ONLY
* Not reliable for round cell tumors
Neoplasia
* 3 general categories:
o Epithelial cells
o Round cells
o Mesenchymal cells
o **Remember to scan at low magnification (10x) first to
assess cell distribution
o Need to evaluate cytologic criteria of malignancy to
determine benign vs. malignant - for epithelial or
mesenchymal tumors ONLY
* Not reliable for round cell tumors
Neoplasia Cytologic Criteria for Malignancy IMPORTANT
* Anisocytosis
o Variation in cell _____ between cells of the same _____.
* Anisokaryosis
o Variation in nuclear ____ between cells of the same _____
* Immature chromatin
* Multinucleation
o A single cell has more than ____ nucleus
* Abnormal mitotic figures
* Nucleolar changes
o Nucleoli are ______ and ____, _______, and/or ______ shaped
- Anisocytosis
o Variation in cell size between cells of the same origin - Anisokaryosis
o Variation in nuclear size between cells of the same origin - Immature chromatin
- Multinucleation
o A single cell has more than one nucleus - Abnormal mitotic figures
- Nucleolar changes
o Nucleoli are enlarged and prominent, multiple, and/or variably shaped
Neoplasia: Epithelial
* Characteristics
o Usually in tightly cohesive clusters
o Polygonal to round shape
o Often distinct intercellular junctions
Neoplasia: Round
* Round cell tumor categories ?IMPORTANT
- Characteristics
o _________ well - samples usually highly cellular
o _______ shape/borders
o Can be in ______ or _________ distributed
o Criteria of ________ not as reliable
Neoplasia: Round
* Round cell tumor categories
o Plasma cell
o Histiocytoma
o Lymphoma
o Transmissible venereal tumor (TVT)
o Mast cell tumor
o +/- melanoma
* Characteristics
o Exfoliate well - samples usually highly cellular
o Round shape/borders
o Can be in clusters or individually distributed
o Criteria of malignancy not as reliable
Neoplasia: round
Neoplasia: Mesenchymal
* Characteristics
o Exfoliate _______ - better suited for histopathology
o Usually distributed both in _______ and _________
o Wispy, ______ to ______, abundant cytoplasm
Neoplasia: Mesenchymal
* Characteristics
o Exfoliate poorly - better suited for histopathology
o Usually distributed both in clusters and individually
o Wispy, attenuated to stellate, abundant cytoplasm
Neoplasia: Mesenchymal
Fluid Analysis
Sample Types?
- Peritoneal
- Pleural
- CSF
- TTW/BAL
- Synovial
- Pericardial
- Ocular
The four basic parts of fluid analysis
Four basic parts
- Color, clarity
- Cell count
- Total protein
- Cytologic evaluation
o Differential cell count
o Cell morphology
o Organisms, etc. - Additional tests may be
indicated
Collecting & Submitting Fluids
* Should be collected into an _____ (_____ top) tube to prevent clotting IMPORTANT
* If cultured, separate aliquot should be collected into red top tube
o EDTA is bacteriostatic and can interfere with culture results (false neg.) IMPORTANT
* If fluid will be processed more than 2 hours after collection, make direct smears
o Send smears, purple top, and red top to the laboratory. Smears help with morphology. Do not send samples for cytology in same containers as histopath b/c formalin fumes damage smear.
Collecting & Submitting Fluids
* Should be collected into an EDTA (purple top) tube to prevent clotting IMPORTANT
* If cultured, separate aliquot should be collected into red top tube
o EDTA is bacteriostatic and can interfere with culture results (false neg.) IMPORTANT
* If fluid will be processed more than 2 hours after collection, make direct smears
o Send smears, purple top, and red top to the laboratory
Gross Examination of Fluids
* Color (can sometimes give you a clue as to etiology)
1. Normal: clear to pale yellow
2. Iatrogenic or true hemorrhage: red
3. Bile: yellow to dark green
4. Urine: bright yellow
5. Turbidity:
* Increased cellularity
* Bacteria
* Fibrin
* Lipid
* Ingesta from GI rupture or accidental enterocentesis
Gross Examination of Fluids
* Color (can sometimes give you a clue as to etiology)
1. Normal: clear to pale yellow
2. Iatrogenic or true hemorrhage: red
3. Bile: yellow to dark green
4. Urine: bright yellow
5. Turbidity:
* Increased cellularity
* Bacteria
* Fibrin
* Lipid
* Ingesta from GI rupture or accidental enterocentesis
Protein and Cell Counts
on Fluids: Methods
* Protein
o Refractometry (peritoneal, pericardial, pleural, synovial fluids)
o Biochemical methods (CSF)
* Cell counts
o Total nucleated cell count (TNCC) typically obtained via automated
hematology analyzer
o WBC differential count obtained by counting leukocytes on a stained
cytology slide
Classification of Effusions IMPORTANT
* Based on total ______ cell count and _____ concentration
* Pure Transudate
o < 2.5 g/dL protein and < 1,500 TNCC/uL
* Exudate
o > 2.5 g/dL protein and > 5,000 TNCC/uL
* Modified Transudate
o Those not meeting the criteria above—somewhere in _______
Classification of Effusions IMPORTANT
* Based on total nucleated cell count and protein concentration
* Pure Transudate
o < 2.5 g/dL protein and < 1,500 TNCC/uL
* Exudate
o > 2.5 g/dL protein and > 5,000 TNCC/uL
* Modified Transudate
o Those not meeting the criteria above—somewhere in between
Hemorrhagic Effusions
Must distinguish from peripheral blood contamination!
* True hemorrhage
o Erythrophagocytosis
* Macs that contain RBCs
o Hemosiderin-laden
macrophages
* Breakdown RBC product
o Supernatant pink, yellow, or orange unless acute hemorrhage
o PCV and protein close to peripheral blood values
* Blood contamination
o Platelets
o Absence of erythrophagocytosis
o Protein and cell counts less than peripheral blood (true hemorrhage vs. blood contaminations)
o Clear supernatant
Hemorrhagic Effusions
Must distinguish from peripheral blood contamination!
* True hemorrhage
o Erythrophagocytosis
* Macs that contain RBCs
o Hemosiderin-laden
macrophages
* Breakdown RBC product
o Supernatant pink, yellow, or orange unless acute hemorrhage
o PCV and protein close to peripheral blood values
* Blood contamination
o Platelets
o Absence of erythrophagocytosis
o Protein and cell counts less than peripheral blood
o Clear supernatant
True Hemorrhage
Hemorrhagic Effusions
* Causes
o Traumatic
* Blunt or penetrating trauma: hit by car, gunshot wound
o Non-traumatic
* Malignant neoplasia (e.g. hemangiosarcoma)
* Hematoma
* Organ torsion (splenic/liver/other)
* Rodenticide toxicosis/other coagulopathies
Chylous Effusion
* Mainly small lymphocytes when acute
o Increasing numbers of neutrophils, macrophages over time
* Often modified transudate
o May be an exudate
* Origin: Leakage of thoracic duct/other lymphatics IMPORTANT
* Chylomicrons present, overall white- pink, opaque, does not clear with centrifugation
* Triglyceride level 2-3x > than in serum
Chylous Effusion
* Mainly small lymphocytes when acute
o Increasing numbers of neutrophils, macrophages over time
* Often modified transudate
o May be an exudate
* Origin: Leakage of thoracic duct/other lymphatics IMPORTANT
* Chylomicrons present, overall white- pink, opaque, does not clear with centrifugation
* Triglyceride level 2-3x > than in serum
Chylous Effusion: Causes
* Pleural cavity:
o Cardiovascular disease
o Neoplasia (when patient has lymphoma, thymoma in thoracic cavity) IMPORTANT - seen in cats.
o Heartworm disease
o Diaphragmatic hernia
o Lung lobe torsion
o Fungal granulomas
o Idiopathic
- Peritoneal cavity:
o Cardiovascular disease
o FIP is one of the most important causes
o Neoplasia
o Steatitis
o Biliary cirrhosis
o Lymphatic rupture/leakage
Chylous Effusion: Causes
* Pleural cavity:
o Cardiovascular disease
o Neoplasia (when patient has lymphoma, thymoma in thoracic cavity) IMPORTANT - seen in cats.
o Heartworm disease
o Diaphragmatic hernia
o Lung lobe torsion
o Fungal granulomas
o Idiopathic
- Peritoneal cavity:
o Cardiovascular disease
o FIP is one of the most important causes
o Neoplasia
o Steatitis
o Biliary cirrhosis
o Lymphatic rupture/leakage
Biochemical Tests on Fluids
* Used to confirm or differentiate between causes of
an effusion
* Fluid analyte level generally compared to serum or
plasma level
Biochemical Tests on Fluids
* Septic effusions
o Serum and fluid glucose concentration difference of > 20 mg/dL helps support septic vs. non-septic effusion
* Fluid glucose concentration < serum glucose (bacteria consume glucose)
o Lactate: septic effusions often have lactate concentrations > blood concentrations
* Chylous effusions
o Triglycerides in fluid often > 3x serum triglycerides
* Bilious effusions
o Fluid bilirubin often several times higher than serum bilirubin
* Uroperitoneum
o Fluid creatinine and potassium concentrations often > 2x serum levels
Biochemical Tests on Fluids
* Septic effusions
o Serum and fluid glucose concentration difference of > 20 mg/dL helps support septic vs. non-septic effusion
* Fluid glucose concentration < serum glucose (bacteria consume glucose)
o Lactate: septic effusions often have lactate concentrations > blood concentrations
* Chylous effusions
o Triglycerides in fluid often > 3x serum triglycerides
* Bilious effusions
o Fluid bilirubin often several times higher than serum bilirubin
* Uroperitoneum
o Fluid creatinine and potassium concentrations often > 2x serum levels
