Term
| When is cytology appropriate? |
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Definition
| cytology is appropriate when you suspect a disease in which the tissue architecture is not important, and in which the lesion is more-or-less diffuse within the tissue. |
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Term
| Collecting a Scraping Sample; |
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Definition
1. for bx specimens, use a scalpel blade to expose a fresh edge of the tissue
2. blot the sample until it is nearly dry
3. hold the blade at a 90 degree angle and scrape across the tissue
4. spread the sample onto a clean slide
b. use a motion like spreading peanut butter
c. if the sample appears thick on the slide, make a compression smear from it
5. Air dry the slide before staining by gently waving it in the air |
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Term
| Collecting a Swab sample: |
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Definition
1. premoisten a swab w saline
a. may need rayon swab, rather than cotton
b. may need sterile swab
2. place the premoistened swab into the cavity
3. roll the swab in a single stroke in layers down the length of a clean slide
4. make 2 or 3 rows
5. air dry the slide before staining by gently waving it in the air. |
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Term
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Definition
| g. Lesion Imprint – may be prepared from external lesions or from tissues removed during sx or necropsy. Easy to collect but collect fewer cells than scrapings and usually contain a gtr amt of contamination than FNBs. Thus, they often reflect only a local secondary bacterial infxn and/or inflammation-induced tissue dysplasia. In many cases the bacteria and tissue dysplasia markedly hinder an accurate dx of neoplasia. The Tzanch preparation is a type of imprint collection that can be used on external lesions |
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Term
| Collecting a Tzanch Sample (Imprint) |
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Definition
Collecting a Tzanch Sample (Imprint)
1. assemble 4 clean slides and # them
2. touch the slide to the lesion on the pt as follows:
- slide 1 – touch the slide to the unprepped lesions (may first lightly wipe the lesion with saline)
- Slide 2 – prep, gently debride, and lightly clean the lesion and touch the slide to the lesion
- Slide 3 – fully debride the lesion, removing any scabs, etc and imprint the exposed area
- Slide 4 – imprint the bottom of the scab if present
3. air dry all slides before staining by gently waving in the air |
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Term
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Definition
| a. Scraping – has the advantage of collecting many cells from the tissue and therefore is advantageous when the lesion is firm and yields few cells. Major disadvantages – more difficult to collect and collect only superficial samples, thus may reflect only a secondary bacterial infxn and/or inflammation-induced tissue dysplasia, which hinders their use in dx of neoplasia. |
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Term
| Collecting an imprint sample: |
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Definition
Collecting an imprint sample:
1. expose a fresh edge on a small piece of tissue
2. blot the sample until nearly dry
3. touch the tissue repeatedly in rows in single file on a clean slide. Repeat blotting as needed
4. air dry the slide before staining by gently waving it in the air |
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Term
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Definition
| c. FNA – use a needle to collect a small sample from masses. For cutaneous lesions, they are an advantage by avoiding superficial contamination (bacterial/cellular) but collect fewer cells. Aspiration or non-aspiration method. If test are to be performed on a portion of the sample collected or a body cavity, such as peritoneal and thoracic cavities and joints, is to be penetrated, the area is surg prepared. otherwise prep is that reqd for vx |
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Term
| Fine Needle Biopsy Aspiration |
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Definition
Fine Needle Biopsy Aspiration
Use 21 – 25g needle and 3 – 20 ml syringe. The softer the aspirated tissue is, the smaller the needle and syringe. The use of a needle larger than 21g not advantageous. (lrgr needles tend to aspirate tissue cores – poor yield of cells and grtr blood contamination. Size of syringe due to consistency of tissue. Softer, such as lymph nodes, often 3ml. firm, such as fibromas, squamous cell carcinomas need lrgr syringe for suction. 12ml good guess
1. stabilize mass
2. insert needle
3. retract plunger to create neg pressure
4. redirect the needle several times
a. do not exit the mass
b. maintain neg pressure
5. remove needle from mass
6. remove syringe from needle
7. fill syringe with air
8. reattach needle
9. gently force sample from needle onto clean slide
10. air dry the slide before staining by gently waving it in the air |
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Term
| Fine Needle Biopsy Nonaspirate Technique: |
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Definition
Fine Needle Biopsy Nonaspirate Technique:
1. stabilize mass
2. insert needle (may have a syringe barrel attached w/o the plunger
3. redirect the needle several times
a. do not exit the mass
b. maintain neg pressure
4. remove needle from mass
a. remove syringe barrel (if used) from needle
5. fill syringe with air
6. reattach needle
7. gently force sample from needle onto clean slide
8. air dry the slide before staining by gently waving it in the air
9. repeat 2 – 3 x if needed in different sites |
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Term
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Definition
| i. Biopsy – sampling of tissue for cytologic and or histopathologic exam. Samples are fixed in 10% neutral phosphate-buffered formalin. Slabs of tissue n more than 1 cm wide in jars containing formalin at approx 10 x the specimen’s volume. With large tissues, the sample can be removed to a smlr jar w/ less formalin after it has been fixed for 24 hrs. Wedge or punch |
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Term
| Punch biopsy sample collection: |
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Definition
Punch biopsy sample collection:
1. gently rotate the biopsy punch in one direction until the punch blade has sectioned the tissue
2. grasp the margin of the tissue with a pair of fine forceps or flush the tissue onto a sm piece of wooden tongue depressor.
3. allow tissue to dry onto the depressor.
4. place the tissue with the attached tongue depressor “splint” |
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Term
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Definition
Romanowsky Stains
- Diff-Quik, other quick Wright’s stains
- Stains organisms and cyctoplasm of cells
- Diff-Quik – does not undergo the metachromatic rxn therefore granules of some mast cells do not stain, resulting in misclassification as macrophages > cmfusion in examination of some mast cell tumors. Increasing the fixative time to approx 15 min may alleviate problem.
- In eval of blood smears or bone marrow aspirates, DiffQuik does not stain polychromatophilic RBCs well and occas does not stain basophils
(Thinner the smear, the less stain time needed, thicker the smear and the greater the total protein concentration, the more time needed)
Romanowsky staining
Romanowsky stains are universally employed for staining blood films and are generally very satisfactory. The main components of a Romanowsky stain are:
1. A cationic or basic dye such as azure B, which binds to anionic sites and gives a blue-grey colour to nucleic acids (DNA or RNA), nucleoproteins, granules of basophils and weakly to granules of neutrophils
2. An anionic or acidic dye such as eosin Y, which binds to cationic sites on proteins and gives an orange-red colour to haemoglobin and eosinophil granules.
There are a number of different combinations of these dyes which vary in their staining characteristics. May-Grunwald-Giemsa is a good method for routine work. Wright's stain is a simpler method, whilst Leishman's is also a simple method which is especially suitable when a stained blood film is required urgently or the routine stain is not available (e.g. at night). Field's stain is a rapid stain used primarily on thin films for malarial parasites. Whichever method is used, it is important to select dyes that are not contaminated with other dyes or metallic salts.
Staining can be carried out in a jar or on a staining rack
May-Grunwald-Giemsa method
1. Air dry slides.
2. Fix in Methanol for 2-3 minutes at room temperature.
3. Stain for 15 mins in May-Grunwald stain freshly diluted with an equal volume of buffered distilled water, pH6.8
4. Stain for 10 minutes in Giemsa stain freshly diluted with buffered distilled water, pH 6.8 (1/9)
5. Wash in running tap-water and then leave for 3-4 minutes in buffered distilled water, pH 6.8
6. Allow to dry. Mount with a coverslip if required, using DPX neutral mounting medium.
Leishman's method
Air dry slides
Flood with neat Leishman's stain for three minutes; as the stain's formulation includes methanol, this will fix the cells.
Dilute the stain on the slide with an equal amount of buffered water, pH 6.8, adding the water slowly with a plastic Pasteur pipette and mixing by sucking the stain up and down with the pipette.
Leave the slide for approximately 12 minutes; the appearance of a polychromatic 'scum' on the surface of the slide is merely a result of oxidation of the dye components and can be ignored.
Wash off excess stain with slowly-running tap water and flood slide for one minute with buffered water, pH 6.8.
Dry the slide and mount with a coverslip if required, using DPX mounting medium.
Field's stain method
Air dry the film and fix in methanol for 2-3 minutes.
Dip the slide into Field's Stain Solution - B (red) and agitate gently for 10 seconds.
Rinse slide with buffered distilled water, pH 6.8
Drain excess water and dip slide into Field's Stain Solution - A (blue) and agitate gently for 15 seconds.
Rinse slide with buffered water, pH 6.8, for 30 - 60 seconds.
Dry the slide upright and mount with a coverslip if required, using DPX mounting medium
http://www.searo.who.int/en/Section10/Section17/Section53/Section480_1732.htm |
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Term
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Definition
New Methylene Blue Stain
- useful adjunct to RS
- stains cytoplasm weakly (which Romanowsky stains very well)
- gives excellent nuclear and nucleolar detail
- because NMB stains sytoplasm weakly, the nuclear detail of cells in cell clumps may be better visualized
- generally, RBCs do not stain with NMB but may develop a pale blue tint, as a result, marked RBC contamination of smears does not obscure nucleated cells |
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Term
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Definition
Papanicolaou Stains
- give excellent nuclear detail and delicate cytoplasmic detail
- allow the viewer to see through layers of cells in cell clumps and evaluate nuclear and nucleolar changes well
- do not stain cytoplasm as strongly as Romanowsky stains and therefore do not demonstrate cytoplasmic changes as well
- do not demonstate bacteria and other organisms as well as Romanowsky stains do |
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Term
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Definition
Papanicolaou Stains
- give excellent nuclear detail and delicate cytoplasmic detail
- allow the viewer to see through layers of cells in cell clumps and evaluate nuclear and nucleolar changes well
- do not stain cytoplasm as strongly as Romanowsky stains and therefore do not demonstrate cytoplasmic changes as well
- do not demonstate bacteria and other organisms as well as Romanowsky stains do
- staining requires multiple steps and considerable time
- reagents often difficult to locate, prepare, and maintain in practice.
- Require the specimens to be wet-fixed (smear must be fixed before the cells have dried). Requires spraying the smear w/ a cytologic fixative or placing it in ethanol immediately after preparation. When the smear is placed in ethanol, it should be made on a protein-coated slide, which prevents the cells from falling off the slide when immersed |
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Term
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Definition
| The study of the microscopic structure of tissues. |
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Term
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Definition
| The study of the microscopic anatomical changes in diseased tissue |
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Term
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Definition
| are usually reserved for patients in which it as easy to resect the mass in its entirety as it is to obtain an incisional biopsy (e.g.; superficial skin masses; lung lobe mass; splenic mass). In these cases, in addition to obtaining a diagnosis, the procedure may be the only therapy required. |
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Term
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Definition
| are typically used in patients with large masses that are difficult to resect in their entirety by means of a relatively simple surgical procedure (e.g.; large subcutaneous sarcoma or mast cell tumor; metastatic liver nodule), or in patients in which a general anesthetic to excise the mass may result in a high risk of complications |
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Term
| 3. For histopathology, list the sample handling and processing procedures for biopsy samples. |
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Definition
Samples for histopathology need to be fixed in the proper type and volume of fixative, and accompanied by a detailed signalment and clinical summary of the patient. The fixative of choice is 10% buffered formalin, used at the ratio of 9 parts of fixative per one part of tissue. Because formalin penetrates only 5 to 10 mm, the samples should be at most 2 cm thick. If the specimen is larger, it
Cytology and Biopsies for the Practitioner
27th WSAVA
Page 2 of 4
should be sliced at 8-10 mm intervals, without cutting through the bottom of the sample, to allow for better fixation. For best results, tissue samples should be fixed for a minimum of 24 hours. Also, samples from different areas (e.g.; a dog or cat with multiple skin masses) should be submitted in separate vials to assure that the clinician will be able to determine which tumor originated form a specific anatomic area, once he/she receives the pathology report. |
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Term
| How to Stain w/ Diff-Quik |
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Definition
Label w/ graphite pencil – not affected by stain solns
- hold by frosted end
- immerse 10 times in each of the 3 diff-quick solns in the following order:
Soln I – fixative soln (lt blue)
Soln II (red)
Soln III (dk blue/purple)
- between the 3 solns, tap the narrow edge of the slide opposite the frosted end on a paper towel to remove excess soln
- rinse w/ distilled water
- air dry in a slide holder (~ 10 – 20 mon depending on temp/humidity) |
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Term
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Definition
- Removes a cross section of the tissue w/in a needle core, types, incl Tru-cut
- Step 1 Incision – for SQ bx samples, 1 – 2 mm incision w/ a scalpel through which the instrument can be inserted to avoid surface contamination
- Step 2 Insertion – introduces the closed bx needle
- Step 3 Sampling – many tools have a stylet and a cutting cannula. Usually position w/in thhe bx site, advance the stylet to expose the specimen chamber, and a final push on the plunger releases the spring of the cutting cannula to sever and capture tissue |
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Term
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Definition
- create slides and/or culture, etc before preserving in formalin
- avoid specimen dehydration. Keep sample hydrated until affixed to slides by wrapping in gauze and moistening in saline so don’t dry out b4 slides prepared. Work quickly, artifactual changes can begin to occur in the specimen in as little as one minute after obtained
- danger of specimen degradation. If prepping gross tissue samples and cytology slides, keep it away from formalin and fumes until slides prepared |
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