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