Cytology Flashcards
What are the advantages of cytology? (4)
simple, quick sampling & examination
inexpensive
minimally invasive
Fast turn around time
When can cytology outperform routine histopathologic exam?
when cell detail is critical (round cell tumors)
What are the advantages of biopsy (histopath)? (4)
Provides info on tissue architecture
Grading
Invasion
Easier to perform immunohistochemical examination (unusual lesions)
What are some common mistakes made during sampling? (9)
creating a vacuum w/ the syringe contaminating the sample w/ blood only sampling the middle of the lesion forceful spraying of the sample too little or too much pressure Not blotting the fresh cut surface dry (imprint smears) Open formalin jars close Refrigerating samples Not adequately describing the lesion (providing too little info)
When is it appropriate to perform an actual aspiration?
If several attempts w/ the needle only have failed
Which type of cells can only be examined in cytology?
only INTACT cells
Why should you provide the DDX along with your cytology preps?
can comment whether or not the cytologic picture is consistent/inconsistent w/ each of the listed DDX
Systematic approach to Cytology Specimens
- Evaluate quality of smear
- Scan entire slide on low mag (4x)
- Assess cellular arrangement
- Decided if it’s inflammatory or neoplastic
What 3 things evaluate the quality of a prep?
Adequate amount of cells
Adequate spread (thin areas)
Adequate staining
What do you do once you have decided a prep is inflammatory?
Decided if septic or not
What are the 3 categories of neoplasia?
Round cell tumor
Epithelial tumor
Mesenchymal/spindle cell tumor
What are the 4 different cell-type classifications for inflammation?
Neutrophilic (suppurative, purulent)
Mixed
Mononuclear
Eosinophilic
What is seen in neutrophilic inflammation?
> 70% of inflammatory cells = neutrophils
What is seen in mixed inflammation?
50-70% neutrophils
remainder: macrophages &/or lymphoid cells
What is seen in mononuclear inflammation?
> 50% of cells are macrophages &/or lymphocytes
What are the 2 types of mononuclear inflammation?
Histiocytic/granulomatous
Lymphocytic
What does the presence of degenerate neutrophils suggest?
lesion was caused by bacterial infection
What are the common sites Histoplasma capsulatum infects?
lymph nodes
intestinal mucosa
bone marrow
What is the main inflammatory cell type seen in Histoplasma capsulatum infections?
macrophages
What are the common sites of infection for Blastomyces dermatiditis?
Draining skin lesions
lymph nodes
respiratory samples
What is the main inflammatory cell type seen in Blastomyces infections?
mostly neutrophils w/ some macrophages `
What is the common site of infection for Dermatophilus congolensis?
scaly, scabby, cutaneous lesions in cattle
What is the main inflammatory cells seen in the lesions of Dermatophilus?
few, mostly keratinzed squamous cells/debris
What is the common site of infection for Sporotrichum schenkii?
draining lesions of cats
What is the main inflammatory cells seen in the lesions of Sporotrichum?
neutrophils, possible degenerate
What are the common sites of infection for Leishmania?
lymph nodes
bone marrow
What is the main inflammatory cells seen in lesions of Leishmania?
macrophages
_____ glands will have relatively normal appearing cells.
Hyperplastic
What are some examples of discrete or round cell neoplasms? (6)
mast cell tumor Canine cutaneous histiocytoma Melanoma (benign/malignant) TVT Cutaneous lymphosarcoma Cutaneous plasmacytoma
What are some examples of BENIGN epithelial neoplasms? (6)
Perianal gland adenoma kertoacanthoma Sebaceous gland adenoma Basal cell tumor/carcinoma Papilloma Many mammary gland tumors
What are some examples of MALIGNANT epithelial neoplasms? (3)
Squamous cell carcinoma
Adnexal gland carcinoma
mammary gland carcinoma
What are some examples of BENIGN non-epithelial neoplasms?
Lipoma
Fibroma
Hemangiopericytoma
What are some examples of MALIGNANT non-epithelial neoplams?
Fibrosarcoma Osteosarcoma Liposarcoma Chondroscarcoma Rhabdomyosarcoma
What 3 malignant non-epithelial neoplasms are invasive to the SQ?
Osteosarcoma
Chondrosarcoma
Rhabdomyosarcoma
How is determination of malignancy usually based?
Based on the morphologic features of pleomorphism
What are the “Cytologic Criteria of Malignancy”?
need to have >3
Anisokaryosis Variable N:C ratio due to large nuclei Poikilokaryosis Abnormally prominent or multiple nucleoli w/ variable sizes/shapes ABNORMAL mitotic figures Nuclear molding Increased cytoplasmic basophilia Abnormal cytoplasmic vacuolization &/or secretory granules
Cytologic characteristics of round cell (discrete) tumors?
4
round cell w/ round nuclei
Individual appearance of cells
Well defined cell borders
Good exfoliation
When is it difficult to distinguish a histiocytoma from an inflammatory lesions?
When the histiocytoma undergoes spontaneous regression
Characteristics of epithelial cells (glandular & non-glandular)?
shape: round, oval, polyhedral or columnar
Arrangement: sheets, clusters or rafts
Well-differentiated cells have abundant cytoplasm
Can have cell-to-cell jxns
Exfoliate well
Characteristics of spindle/mesenchymal cells (C.T.)?
Shape: elongated or spindle-form w/ cytoplasmic tails
Arrangement: individually or unorganized clumps of cells
Scant cytoplasm w/ indistinct cell borders
Exfoliate poorly
What do you never do when interpreting lymph node aspirates? Why?
Interpret under-stained areas
will always look like lymphoma
What are the 5 categories for Lymph Nodes?
Normal Hyperplastic/reactive Lymphadenitis Lymphoma Metastatic neoplasia
Cell types found in a “Normal” Lymph node?
> 90% small, mature lymphocytes
low #’s of medium to large lymphocytes
Occasional macrophage
Definition of a hyperplastic lymph node.
Enlarged lymph node w/ cell proportions similar to normal tissue
Cell types found in a “Hyperplastic” lymph node?
incr. # of MD to LG lymphocytes (still < 50%)
possible incr. in plasma cells & mitotic figures
“Lymphadenitis” is due to ________.
incr. % of inflammatory cells
Neutrophilic lymphadenitis
increase in neutrophils ( > 5%)
Eosinophilic lymphadenitis
increase in eosinophils ( > 3%)
Histiocytic lymphadenitis
increase in macrophages
Celly types found in a “Lymphoma” lymph node?
> 50% immature (MD to LG) lymphocytes (MONOTONY) Possible incr in mitotic figures low #'s of small, mature lymphocytes \+/- plasma cells
Cell type found in a “Metastatic neoplasia” lymph node?
foreign cells
What are the advantages of liver cytology?
complements other DX tools
may provide a specific DX
cheap, non-invasive, safe
What are the limitations of Liver cytology.
best for diffuse lesions
Does NOT replace histopathology
What is the gold standard for examining liver cytology?
histopathology
What are the parts of the respiratory tract that can be evaluated by cytology?
Nasal cavity-nasal flush
Airways- LRT by trans tracheal wash or BAL
Lungs (paranchyma)-FNA
Thoracic Cavity- Pleural flush
What do you need to do before you collect a histopathology/cytology sample of the nasal cavity?
Check clotting function and CBC
Are nasal swabs useful for cytology?
Sometimes, if lots of discharge is present, can ID fungal infections, but it is often nonspecific and only ID’s inflammation.
What is the best way to collect cells from the nasal cavity?
Nasal Flush
What are normal findings in nasal cytology?
Low cellularity
small amounts of mucus
Low numbers of extra cellular bacteria (normal flora)
Epithelial cells
What do normal epithelial cells of the nasal cavity look like?
Non-keratinized squamous with surface bacterial.
Cilliated colomnar respiratory epithelium
goblet cells
What are abnormal cytology findings from the nasal cavity?
Rhinitis (inflammation)- Neuts, Macs, lymphos, plasma cells with or w/o fugni or bacteria
Increased mucus & goblet cells
Changes to epithelial cells- hyperplasia, dysplasia, metaplasia
What are the 4 types of rhinitis and what cells do you find?
BacT- degenerate Neuts w/ IC bacT. (2ary to foriegn body)
Fungal- Neuts and Macs maybe fungi, can be hard to dx
Allergic- Eos, Neuts, Mast & Plasma cells (rare)
Chronic-Lymphos, plasma cells, Macs and Neuts
What types of Neoplasia occur in the nasal cavity?
Adenocarcinoma, squamous cell carcinoma and lymphoma (cats)
Can neoplasia be Dx via nasal flush?
Yes but often require histopathology. Need to be able to differentiate btwn hyper/meta/dysplasia
