Cytology Flashcards
What is Exfoliative Cytology?
examination of cells in body fluids (CSF, peritoneal, pleural, and synovial fluids), on mucosal surfaces (vaginal, trachea), or in secretions (semen, prostatic fluid and milk)
What is the primary purpose of Cytology?
to differentiate inflammation from neoplasia
What are several ways Cytology samples are prepared?
- impression smears
- compression or modified compression preparations
- line smears
- starfish smears
- wedge smears
What are some Common Pitfalls of Cytology?
- improper specimen collection
- staining techniques are variable and subject to great error than standard staining methods
- formalin fumes near specimen collection or processing areas cause cells to become partially fixed and therefore unuseable for cytological evaluation
What is Histopathology?
- evaluates cellular architecture
- preparation involves several complex steps and specialized equipment
What is Cytology?
- evaluations observe cells individually or in small groups
- cells in cytology preparation are randomly distributed with no evidence of in vitro relation to one another
What are methods of Sample Collection?
- swabs
- scrapings
- imprints
- fine needle biopsy
- tissue biopsy
- centesis
- transtracheal/bronchial wash
When are Swabs collected?
only when imprints, scrapings and aspirates cannot be made
What is the procedure for collecting Vaginal Samples?
- restrain animal in standing position with tail elevated
- clean and rinse vulva, insert lubricated speculum or smooth plastic tube to a point just cranial to urethral orifice in vagina
- cells collected are exfoliated from vaginal wall (epithelial cells and neutrophils) and pass through the vagina from the uterus
What may Ear Samples contain that interferes with evaluation?
excess amounts of wax
What is done to Ear Samples to remove the wax?
pass slide through a flame or gentle heat from a warm hair dryer to dissolve wax
What can Smears of Scrapings be prepared from?
tissues collected during necropsy, surgery or from external lesions on a living animal
What are Scrapings useful for?
collection of cells from firm lesions
What are Major Disadvantages of Scrapings?
- more difficult to collect
- collect only superficial cells
What is the Scraping Procedure?
- prepare scraping by holding a scalpel blade perpendicular to cleaned and blotted surface of lesion and pull blade across lesion several times
- transfer material collected on blade to middle of glass slide and spread like peanut butter
What are Imprints prepared from?
external lesions on the living animal or tissues removed during surgery or necropsy
What is the Imprint Procedure?
- to prepare imprints from tissues collected during surgery or necropsy, remove blood and fluid from surface of lesion being imprinted by blotting with a clean absorbent material
- touch middle of a clean glass slide against blotted surface to be imprinted
- make multiple imprints on each slide
What should be done if a delay occurs from time of sample collection until imprint is taken?
use a scalpel blade to expose a fresh surface before blotting and making impression
What is the Tzanch Preparation?
- prepare atleast 4-6 clean glass slides
- imprint lesion before it’s cleaned and designate as slide 1
- clean lesion with saline moistened surgical sponge and re-imprint on slide 2
- debride lesion and re-imprint on slide 3
- if scab was present, imprint underside of scab and labe as slide 4
Where are Fine Needle Biopsys collected from?
masses including lymph nodes, nodular lesions, and internal organs
What is the Aspiration Procedure?
- use a 21-25g needle and a 3-20ml syringe
- the softer the aspirated tissue, smaller the needle and syringe
- hold mass to be aspirated firmly to aid penetration of skin and mass and control direction of needle
- introduce needle, with syringe attached, into center of the mass, apply strong negative pressure by withdrawing the plunger to approximately 3/4 the volume of syringe
- widely sample mass by redirecting needle to several areas
- maintain negative pressure during re-direction and movement of needle
- when material is observed, relieve negative pressure from syringe and withdraw needle from mass and skin
How do you prepare an Aspiration Slide?
- remove needle from syringe and draw air into syringe
- replace needle onto syringe, expel some tissue in barrel and hub of needle onto middle of glass slide by rapidly depressing plunger
What is the Non Aspirate Procedure
- hold mass to be sampled firmly to aid penetration of skin and mass and help direct the needle
- introduce 22g needle into mass
- can leave syringe with plunger removed attached to needle to facilitate handling
- move needle rapidly back and forth through mass 5-6 times along the same track
How do you prepare a Non Aspirate Slide?
- remove needle from mass and attach a 10ml syringe prefilled with air
- expel material onto a clean glass slide by rapidly depressing plunger
- repeat procedure 2-3 times in different sites to have adequate slide numbers and areas of mass to evaluate
What is a Tissue Biopsy?
sampling of a piece of tissue for cytologic and/or histopathologic examination
What are the techniques of collecting a Tissue Biopsy?
- gentle abrasion with a blade
- excision including punch biopsy and endoscopic guided biopsy
Should you scrub a lesion or disrupt any scales, crusts or surface debris?
no
What is the fixative of choice for Histopathologic Samples?
10% neutral phosphate buffered formalin
How do you ensure adequate fixation of a Tissue Biopsy?
place slabs of tissue no more than 1cm wide, in fluid tight jars containing formalin at approximately 10 times the specimen’s volume
How do you prepare a Tissue Biopsy to be sent off to an outside lab?
- blot specimen gently on paper towel
- place on small piece of wooden tounge depressor, allow tissue to dry to “splint”
- immerse or float specimens with attached “splint” specimen side down in fixative
What are the advantages of Wedge Biopsy?
- large, variably sized specimen
- can be easily oriented by pathology tech
How is a Wedge Biopsy performed?
use a sharp scalpel blade to excise entire lesion or take a wedge from an area of the lesion, through a transition zone to normal tissue
What are Keyes?
cutaneous biopsy punches (4,6, 8mm disposable skin biopsy punches)
How many sutures do Punch Biopsy require?
1 or 2
What is Centesis?
introduction of a needle into any body cavity or organ to remove fluid
What Centesis procedures require general anesthesia?
CSF
synovial fluid
aqueous and vitreous humor
What needle and syringe is needed for a Centesis Procedure?
21g, 60ml
What is the Centesis Procedure for a Thoracocentesis on a Small Animal?
perform with animal in standing position
-needle is inserted in 7th or 8th intercostal space along cranial aspect of rib
What position is an animal in during an Abdominocentesis?
standing or lateral
Cytologic samples obtained from trachea, bronchi or bronchioles may assist with diagnosis of what?
pulmonary diseases of animals
What is the Percutaneous Technique?
involves insertion of needle into trachea through cricothyroid membrane and infuse saline and collect fluid when animal coughs
What is the Orotracheal Technique?
involves placing an ET in an anesthetized patient and collecting fluid through a jugular or urinary catheter
What is the Bronchoalveolar Lavage Technique?
orotracheal technique used to collect samples from the lower respiratory tract
bronchoscopy is preferred
What is the Nasal Flush Technique?
used for collecting cytologic samples from nasal cavity to investigate diseases affecting the upper airway
What are the types of Smear Preparations?
- compression technique
- combination technique
- starfish smear
How is the Compression Technique Prepared?
- made by expelling aspirate onto middle of one slide and gently placing a second slide over aspirate horizontal with and at right angles to first slide
- spreader slide is quickly and smoothly slid across prep slide, do not place pressure on spreader slide
What is the Combination Technique?
procedure produces a slide that contains a compression preparation on the back 1/3 of the aspirate, the middle 1/3 is untouched, and the front 1/3 of the aspirate is gently spread similar to a blood smear
How is the Starfish Smear performed?
- drag aspirate in several directions with point of syringe needle to produce a starfish shape
- least damaging to fragile cells but allows a thicker layer of tissue fluid to remain around cells
Samples for cytologic examination should be placed in what tube?
EDTA tubes
What influences the selection of a smear technique?
cellularity, viscosity and homogeneity of fluid
What is a Line Smear?
like a blood smear except slide is raised directly upward 3/4 of the way through smear, yielding a line containing a much higher concentration of cells than the rest of the smear
What is a Wedge Smear?
like a blood smear
What is the fixative of choice for Cytology samples?
methylene blue
How long should prepared Cytology slides remain in fixative?
2-5 minutes
What type of stains are used for Cytology?
romanowsky stains
new methylene blue
panpanicolaou stains
When are slides sent to an outside lab?
when in house evaluation of cytology doesn’t provide sufficent, reliable info, or for histopathology
What should be sent to the outside lab?
submit 2-3 air dried, unstained slide and 2-3 dried, stained slides
EDTA and/or sterile serum tubes of samples if applicable
What should be performed during Initial Microscopic Evaluation?
- perform initial evaluation of cytology with low magnification to determine if staining is adequate and to detect any areas of increased cellularity
- large objects (cell clusters, parasites, crystals, and fungi) will also be apparent if present
- use initial eval. to characterize cellularity and composition of sample by recording types and relative numbers of cells present
What should be done during Microscopic Evaluation?
- high power examination should be performed to evaluate and compare individual cells and further characterize types of cells present
- use oil immersion to identify and differentiate evidence of inflammation vs. neoplasia
- cytology report should indicate cell types present, appearance and relative proportions
What is Inflammation?
normal physiologic response to tissue damage or invasion by microorganisms
What are Cytology samples from inflammatory sites characterized by?
presence of WBC’s particularly neutrophils and macrophages
What might occasionally be seen in Inflammation samples?
eosinophils and lymphocytes
What do fluid samples of Inflammation look like?
turbid and white or pale yellow
What is Suppurative (purulent) Inflammation?
presence of large numbers of neutrophils (usually >85% of total nucleated cell count)
What is Granulomatous or Pyogranulomatous Inflammation?
more than 15% macrophages present
What is Eosinophilic Inflammation?
greater than 10% of eosinophils + increased neutrophils
What do Neoplasia specimens usually contain?
homogenous populations of a single cell type
What is Benign Neoplasia?
hyperplasia with no criteria of malignancy present in nucleus of cells
What is Malignant Neoplasia?
cells displaying at least 3 abnormal nuclear configurations
What are the Nuclear Criteria of Malignancy?
- anisokaryosis, macrokaryosis
- pleomorphism
- high or variable N/C ratio
- increased mitotic activity (mitotic figures)
- coarse chromatin pattern
- nuclear molding
- multinucleation
- nucleoli that vary in size, shape and number: anisonucleolosis, macronucleoli, angular nucleoli, multiple nucleoli
What are the primary types of tumors encountered in vet med?
- epithelial cell tumors
- mesenchymal cell tumors
- round cell tumors
What are Epithelial Cell Tumors?
aka carcinoma or adenocarcinoma
samples tend to be highly cellular and often exfoliate in clumps
What are Mesenchymal Cell Tumors?
aka sarcoma
usually less cellular, exfoliate singly or in wispy spindles
What are Round Cell Tumors?
include: histiocytoma, lymphoma, mast cell tumors, plasma cell tumors, melenoma
exfoliate well but not usually in clumps or clusters
Lymph Nodes may show evidence of:
inflammation (lymphadenitis), hyperplasia (benign neoplasia), mixed (both inflammator and neoplastic cells present), neoplasia (lymph node cells with abnormal nuclear features) and metastasis (neoplastic cells from other body tissues that spread to lymph nodes)
What is Primary Lymphoma characterized by?
predominance of lymphoblasts, mitotic figures are common
What are other neoplastic cells that may be present in lymph node aspirates?
mast cells, carcinoma cells, sarcoma cells, histiocytes
What do “normal” Ear cytology samples contain?
cornified squamous epithelial cells with negligible evidence of inflammation and a few microorganisms
What are common abnormal findings in Ear Cytologies?
bacteria and yeasts with or without inflammation
What are abnormalities found in Ear Cytologies?
inflammation caused by sepsis, fungi and yeasts and neoplasia
Anestrus
bitch has no vulvar swelling and doesn’t attract males
What cells are seen in Anestrus?
- predominately intermediate and parabasal cells
- superficial cells are absent
- may contain neutrophils, but no RBC’s
Proestrus
swollen vulva with reddish discharge
attracts males
not accepting males
What cells are seen in Proestrus?
- high number of RBC’s
- intermediate and parabasal cells
- RBC’s gradually decrease, presence of superficial cells are seen
Estrus
swollen vulva
pinkish to straw colored discharge
accept males
attractive to males
What cells are seen in Estrus?
all squamous cells
rising levels of estrogen
Diestrus
no vulvar swelling or discharge
no longer attracts males
no longer accepts males
What cells are seen in Diestrus?
neutrophils increase
RBC’s
intermediate and parabasal cells
