Cytology AI Flashcards
How should smears be dried before placing them in slide containers or before staining?
By waving them or using a hair dryer. Don’t blow on them!
What method can be used to aid in drying viscid samples such as synovial fluid or salivary samples?
The use of a cold air stream, such as a hair dryer.
Is additional fixation necessary after drying the smears?
No, additional fixation is not necessary.
What precaution should be taken when packaging cytology and biopsy samples together?
Cytology should not be packaged in the same plastic bag as the biopsy to avoid formalin fumes affecting staining and compromising the sample.
What are some complications that can arise from fine needle aspirations (FNA)?
Complications include bleeding disorders, infection at the aspirated site, needle tract tumor implantation, and pneumothorax.
How should impression smears be performed? What should be done with the tissue before touching it to a slide?
The cut surface of the excised tissue should be blotted on a paper towel/filter to remove blood and excess fluid. The tissue is then touched firmly on to the surface of a clean slide in several places.
What should be done before collecting cytological samples using the scraping technique?
Any excess exudate should be gently cleaned from the surface of the lesion.
What instruments can be used for scraping of the lesion during sample collection?
A sterile spatula (e.g. Kimura spatula) or the blunt end of the butt of a sterile scalpel blade can be used for scraping.
What is a recommended way to collect a cellular sample using a swab for a dry lesion?
Moistening the swab with sterile saline prior to collection can increase the adhesion of cells to the swab.
How should the swab be rolled on the glass slide during sample collection?
The swab should be rolled in the center of the glass slide gently, without dragging it, to avoid cell damage.
Is it necessary to go back and forth over the same area on the glass slide during sample spreading?
No, the spreading of the material must be done in one direction only, without going over the same area in the glass slide.
Are there any specific swabs for sample collection?
Yes, there are specific swabs for the collection of samples.
How should tissues with a fibrous component be handled during impression smears?
If fibrous tissues do not exfoliate well with the impression smear technique, they can be roughened or scraped with a scalpel blade before touching them to the slide.
What precaution should be taken to avoid blood contamination during scraping of a lesion?
One should try to avoid blood contamination during scraping of the lesion.
What should be done with excess exudate before collecting cytological samples using the scraping technique?
Excess exudate should be gently cleaned from the surface of the lesion before collecting cytological samples using the scraping technique.
How many times should the margin of the lesion be scraped during sample collection using the scraping technique?
The margin of the lesion should be scraped several times in the same direction (not back and forth) until a small drop of material is collected on the spatula/blade.
What are the three types of tubes that cytological samples should be split between?
Cytological samples should be split between EDTA (cytology, cell counts), plain (chemistry), and plain sterile tubes if culture may be needed.
What are the recommended sample preparation techniques for cytological samples?
Fresh smears should always be made (including any flocculent material) if the sample is not to be processed immediately. If the sample is of low cellularity, a line smear or smear of the sediment should be performed. If the sample is very bloody, a direct smear and a buffy coat smear should both be performed.
What should be noted when examining the macroscopic characteristics of the fluid sample?
The macroscopic characteristics of the fluid sample, such as color, turbidity, and smell, should be noted in case these change with a delay in processing the sample.
What should be done with cytology smears that are not processed immediately?
Cytology smears that are not processed immediately should be refrigerated but never frozen, as freezing will rupture the cells.
What should be considered when evaluating the quality of a cytology smear under low magnification?
Under low magnification, you should consider if the sample is representative for the lesion and collection technique, if the sample is cellular enough to draw a conclusion, if the cells are well preserved and not condensed, ruptured, or stretched, if the cells are adequately stained, and if the distribution of cells is uniform throughout the smear or heterogeneous/haphazard.
What is the recommended approach to examining a cytology smear?
Start on low power to locate the cellular parts of the slide and scan the entire slide. Identify the areas of interest and increase the magnification. Once oil immersion is used, the 40x objective cannot easily be used again, so leave this to last.
What should be examined regarding the background of a cytology smear?
The background of a cytology smear should be examined for the presence of blood, distinguishable from inflammation, as well as for cellular products such as mucus/mucin, protein precipitate, osteoid, or amorphous cellular debris. Granulated cells that rupture should be differentiated from bacteria.
What should be noted when tissue cells are present in a cytology smear?
When tissue cells are present in a cytology smear, you should note their arrangement (clusters, sheets, clumps), any architectural patterns, if there are any morphological changes within the population indicating malignancy, and if they are related to any secretory material or matrix.
What is the recommended magnification for searching for bacteria?
x1000
How can stain precipitate be differentiated from bacteria?
Stain precipitate is usually refractile and varies in size and shape, while bacteria are non-refractile and have the same size, shape, and staining characteristics (unless several different types are present).
What distinguishes contamination from infection when bacteria are seen?
Contamination may come from the patient itself or from outside the patient. Typically, a mixed population of bacteria are present with no inflammatory response in contamination. In genuine infection, there is often a single population of bacteria, an associated neutrophilic inflammatory response with degenerate neutrophils, and intracellular bacteria.
What are the possible causes of eosinophilic inflammation?
Eosinophilic inflammation is usually associated with parasitic infections, hypersensitivity reactions, and eosinophilic granuloma, plaques, or disease. It can also be seen along some neoplasms, notably mast cell tumors and lymphomas. Less frequently, eosinophilic inflammation can also be seen with foreign body reaction or fungal infection.
What is the difference between macrophage-rich inflammation and pyogranulomatous inflammation?
Macrophage-rich inflammation is when approximately 50% of the cells are macrophages. Pyogranulomatous inflammation is defined as a mixture of neutrophils (60-70%) and macrophages (20-30%).
What are the potential causes of macrophage-rich inflammation or pyogranulomatous inflammation?
Causes can include foreign body reactions, fungal infections, bacterial infections (Mycobacteria, Actinomyces, and Noocardia), and chronic inflammation (e.g., as a progression of neutrophilic inflammation).
When are medium-sized and large lymphocytes considered suspicious?
A monomorphic population of medium or large cells among lymphocytes should be regarded with suspicion.
What is the most common type of inflammatory response where all types of inflammatory cells are noted?
Mixed cell inflammation is one of the most common types of inflammatory responses where all types of inflammatory cells are noted without a clear predominant type.
What are the main strengths of cytology as a diagnostic technique?
Cytology is considered a fairly safe and non-invasive technique that provides fast results. It is relatively inexpensive compared to other techniques and can often give a specific diagnosis with little effort. Additionally, cytology samples can be obtained without sedation or anesthesia.
What are the main limitations of cytology?
The main limitations of cytology are often related to sample quality, such as cell numbers or cell preservation. Another limitation is the absence of tissue architecture, meaning that cytology cannot show how cells relate to the surrounding tissues. There can also be difficulty in identifying poorly differentiated tumors on cytology.
Which factors should be considered for obtaining the best results from cytology samples?
For optimal cytology samples, one should consider selecting the best sampling technique based on the type of lesion or tissue, ensuring adequate preparation of smears, using proper staining techniques, and correctly examining the smear and interpreting the findings.
What types of tissues and fluids can be evaluated by cytology?
Cytology can be performed on aspirates of cutaneous and subcutaneous masses, lymph nodes and internal organs (ultrasound-guided FNA), along with body cavity fluids. Other samples such as urine, prostatic washes, synovial fluids, bronchial and tracheal washes, nasal flushes, impression smears from various sources, and biopsy samples can also be evaluated by cytology.
Which sampling techniques are recommended for fluid samples?
In general, fluid samples should be collected in EDTA to preserve cells and prevent clotting. Additionally, a plain sterile tube should be used in case culture is needed alongside cytology.
Why is ultrasound guidance recommended during needle aspiration?
Ultrasound guidance is recommended during needle aspiration to leave one hand free to direct the probe and to reduce blood contamination in highly vascular masses/organs.
What should be done if blood is noted in the hub of the needle during the procedure?
If blood is noted in the hub of the needle during the procedure, the procedure should be stopped as further aspiration will only result in increasing the degree of blood contamination of the sample.
After obtaining fluid from a mass lesion, what should be done next?
After obtaining fluid from a mass lesion, all fluid should be drained and placed in an EDTA tube. The mass lesion should then be sampled with a new needle directed at the more solid portion of the mass.
What should be done if a large lesion contains a necrotic center or has a complex, mixed pathology?
If a large lesion contains a necrotic center or has a complex, mixed pathology, the needle should be redirected within the lesion to include the different areas including center and margin.
What should be done if a great deal of material has been obtained during the procedure?
If a great deal of material has been obtained during the procedure, the sample should be split between several smears or the resulting samples may be too thick to visualize internal detail within individual cells.
What is the preferred method for preparation of slides of material collected by FNA?
The slide over slide (flat) technique is probably the best method for the preparation of slides of material collected by FNA.
What is the important point to remember while performing the slide over slide technique?
NO downward pressure should be applied during the slide over slide technique as it ruptures cells, especially in abdominal aspirates and lymph nodes.
What technique is used when the material collected is mainly a cellular fluid?
The blood smear technique is used when the material collected is mainly a cellular fluid.
What can be determined by evaluating the main cell type present in the smears?
The type of inflammation can be determined.
What is the purpose of Diff-Quik stain?
Diff-Quik stain is used to stain smears for evaluation of cell types and inflammation.
What type of stain is Giemsa?
Giemsa stain is a type of stain used in automated stainers.
How should slides be prepared for staining with Diff-Quik?
The slides should be air dried and then dipped in fixative and stain solutions.
What should be done if the stains become exhausted during staining with Diff-Quik?
The slides should be dipped more often in the staining solutions.
What is the purpose of Solution 2 in Diff-Quik staining?
Solution 2 is the eosinophilic stain used to provide a pink color.
What should be done to remove the scum formed on the surface of Solution 2 in Diff-Quik staining?
The scum can be removed with a piece of card or paper.
What type of samples should be stained using the ‘dirty’ set of stains?
Samples likely to contain bacteria or where stain precipitate will not interfere with interpretation should be stained using the ‘dirty’ set.
What is the purpose of the Giemsa stain?
The Giemsa stain is used for staining microscopic organisms, providing better nuclear detail.
What is the recommended fixative for the Gram stain?
The recommended fixative for the Gram stain is alcohol or heat fix.
What is the counterstain used in the Gram stain?
Neutral red is used as the counterstain in the Gram stain.
How can gram positive and gram negative organisms be distinguished in the Gram stain?
Gram positive organisms appear blue-black, while gram negative organisms appear red.
What is the purpose of the Ziehl-Neelsen stain?
The Ziehl-Neelsen stain is used to detect acid-fast bacteria.
What is the decolorizing agent used in the Ziehl-Neelsen stain?
Acid/Alcohol (3% HCl in ethanol) is used as the decolorizing agent in the Ziehl-Neelsen stain.
What is the recommended magnification for examining the Ziehl-Neelsen stain?
Examine under oil immersion (1000x) for the Ziehl-Neelsen stain.
What is the composition of neutrophilic inflammation?
Neutrophilic inflammation consists of more than 85% neutrophils, along with a mixture of macrophages, lymphocytes, eosinophils, and plasma cells.
What are some cellular types involved in inflammation?
The cellular types involved in inflammation can include Mott cells, flame cells (both modifications of plasma cells), fibrocytes, and fibroblasts.
What are Mott cells and flame cells?
Mott cells and flame cells are both modifications of plasma cells that can be seen in inflammatory lesions.
When can fibrocytes and fibroblasts be seen in inflammation?
Fibrocytes and fibroblasts are often seen alongside extracellular matrix (e.g. collagen) in cases where there is fibroplasia secondary to the inflammation.
What are some atypical characteristics that cells in inflammation can exhibit?
Cells in inflammation can exhibit several atypical characteristics, including criteria for malignancy (as a result of dysplasia, a reversible morphological change that mimics neoplasia).
What is dysplasia in the context of inflammation?
Dysplasia is a reversible morphological change that mimics neoplasia and can occur in cells at the inflamed site.
What can make the diagnosis of neoplasia more difficult in the presence of inflammation?
The presence of concurrent inflammation and criteria for malignancy in the tissue cells can make the diagnosis of neoplasia more difficult.
What does FNA stand for?
FNA stands for Fine Needle Aspirate.
When is sterility necessary for collecting samples?
For most ulcerative or proliferative external lesions, sterility is not necessary.
What should be used to clean the area before collecting samples?
An alcohol swab should be used to clean the area.
When should alcohol be used as coupling media?
Alcohol should be used as coupling media when collecting samples with ultrasound guidance.
What specimens can be obtained through a Fine Needle Aspirate?
Hard cutaneous/subcutaneous masses, bone lesions, lymph nodes, vascular lesions/organs, and soft tissue can be obtained through a Fine Needle Aspirate.
What preparation technique is recommended for non-suction cutaneous/subcutaneous masses?
Squash preparation is recommended for non-suction cutaneous/subcutaneous masses.
What can cause blood contamination in cytological specimens?
Using aspiration can cause blood contamination in cytological specimens.
What technique is suggested if the non-aspiration technique is unsuccessful?
If the non-aspiration technique is unsuccessful, the suggestion is to proceed to the aspiration technique.
What is the cytological appearance of cysts?
Cysts yield a low cellularity fluid/sample. Microscopically, there are numerous superficial keratinised squamous epithelial cells, anucleated or with small pyknotic nuclei, keratin scrolls, degenerate keratin debris, scattered cholesterol crystals, and sometimes, free melanin granules.
How is seromas characterized cytologically?
Seromas yield a yellowish to serosanguinous fluid, usually with low cellularity. Microscopically, the background is stippled and eosinophilic, with a predominance of mononuclear cells (macrophages/monocytes and cyst lining cells), vacuolated cytoplasm, and low numbers of non-degenerated neutrophils.
What do haematomas contain cytologically?
Haematomas contain many red blood cells, macrophages that may contain red blood cells phagocytosed, intracellular haem pigment (haemosiderin grey-black pigment), Haematoidin crystals (golden rhomboid crystals). Platelets are only seen in cases of recent haemorrhage/iatrogenic blood contamination. In the latter, no haemophagocytosis, haemosiderin, or haematoidin are present.
What is the cytological appearance of calcinosis cutis or circumscripta lesions?
Calcinosis cutis or circumscripta lesions yield a gritty, chalky material which microscopically is seen as a granular material either fine and purple (necrosis) or refringent (mineral) amorphous material. This is often accompanied by a mixed inflammatory process, mostly with macrophages, including giant multinucleated cells, followed by non-degenerated neutrophils, lymphocytes, and fibroblasts.
Where do lesions of calcinosis circumscripta occur?
Lesions of calcinosis circumscripta occur in areas of repeated trauma or pressure points, leading to the deposition of calcium crystals in the dermis or subcutaneous tissue. Usual affected sites include dorsal neck, inguinal area, and axillary region.
What is hyperplasia and where is it commonly seen?
Hyperplasia is the enlargement of a specific tissue. Cases of hyperplasia are usually seen in epithelial tissues (e.g., prostate) or lymph nodes. In epithelial tissue hyperplasia, the cells exhibit a normal morphology, making a definitive cytological diagnosis impossible. The clinical information needs to be considered for a suspected diagnosis.
What are the typical locations for plasma cell tumors (plasmacytomas) in dogs?
Plasma cell tumors (plasmacytomas) are more common in old dogs and often present as solitary masses in the digits, ears, and mouth.
How do plasma cell tumors (plasmacytomas) appear cytologically?
Plasma cell tumors (plasmacytomas) appear as highly cellular samples with moderately pleomorphic plasma cells. These cells are discrete round to oval cells with a moderate to low nuclear to cytoplasmic ratio, moderate amounts of deeply basophilic cytoplasm, and frequently exhibit a clear perinuclear halo (Golgi apparatus).
What is the typical macroscopic appearance of cutaneous lymphoma?
The macroscopic appearance of cutaneous lymphoma is highly variable, but plaque-like lesions are more frequently observed.
What additional tests should be considered when the predominant cell in cutaneous lymphoma is the small lymphocyte?
When the predominant cell in cutaneous lymphoma is the small lymphocyte, additional tests such as histopathology, immunocytochemistry, or PARR testing should be considered to differentiate it from normal lymphoid tissue or lymphocytic inflammation.
Where is TVT (transmissible venereal tumor) commonly seen in dogs?
TVT (transmissible venereal tumor) is rare in the UK but is seen more frequently in imported dogs. It is seen more frequently in the genitalia but has also been described in the nose and skin.
How do TVT (transmissible venereal tumor) cells appear in aspirates or impression smears?
TVT (transmissible venereal tumor) cells in aspirates or impression smears yield highly cellular smears with high numbers of discrete round cells. These cells have a moderate to high nuclear to cytoplasmic ratio, round nucleus, moderate amounts of pale basophilic cytoplasm often containing multiple clear punctate vacuoles.
What are some typical architectural patterns seen in epithelial and mesenchymal tissues?
Some typical architectural patterns include perivascular, storiform, acinar, pavement, honeycomb, palisading, papillary, and trabecular patterns.
What are the general characteristics of benign tissues in terms of cell population and morphology?
Benign tumors generally demonstrate a uniform population of cells closely resembling that of normal tissue. Criteria for malignancy are usually sparse and mild. The cells tend to maintain their normal size, have a low nuclear to cytoplasmic ratio (except for cells with a naturally high ratio), and a nucleus with uniform chromatin, usually dense. Nucleoli may be absent or nuclei may exhibit a uniform chromatin.
What are some limitations of diagnosing neoplasia with cytology?
Diagnosing neoplasia with cytology can be useful but it has limitations. Inflammation can cause tissue cells to be dysplastic and mimic neoplasia. Additionally, there are neoplasms that may not show cytological criteria for malignancy but still exhibit aggressive behavior and tendency to metastasize.
Why is confirmation with histopathology recommended when inflammation and tissue cells are seen together?
When inflammation and tissue cells are seen together, it could be due to primary inflammation with secondary dysplasia or primary neoplasia. To confirm the diagnosis, it is always recommended to perform histopathology.
Which neoplasms rely on grading to predict their behavior?
Neoplasms such as mast cells and soft tissue sarcomas rely on grading to predict their behavior.
Is there an established grading system for cytology of certain neoplasms like mast cells and soft tissue sarcomas?
No, a grading system for mast cells and soft tissue sarcomas in cytology has not been established. However, follow-up with histopathology for appropriate grading is essential.
Can neoplasms without cytological criteria for malignancy still behave malignantly?
Yes, some neoplasms like thyroid carcinoma, anal sac adenocarcinoma, hepatocellular carcinoma, and fibrosarcoma may not show cytological criteria for malignancy but can still exhibit aggressive behavior, rapid clinical progression, and metastasis.
How do fibroblasts appear in lesions with fibroplasia or in granulation tissue?
Fibroblasts in lesions with fibroplasia or in granulation tissue are generally enlarged, plump, and exhibit several criteria for malignancy. However, in cases where inflammation and fibroblasts are present, histopathology should be considered for suspected cases.
What can cause damaged cells in cytology samples?
Cells can be damaged during the smearing process or by delay in sample processing, especially in fluid samples. When cells are damaged, they may appear as bare nuclei within a sea of cytoplasm and should not be evaluated.
Why can macrophages/histiocytes be challenging to identify in cytology?
Macrophages/histiocytes can be challenging to identify because of their lability in appearance and ability to take on varied morphologies. They may fulfill criteria such as anisocytosis, anisokaryosis, multinucleation, and vacuolation, making them difficult to distinguish between non-transformed macrophages and neoplasia.
What are the major groups of cell types?
The major groups of cell types are epithelia, mesenchymal, and round or discrete cell neoplasms.
How do epithelial cells generally appear on cytology?
Epithelial cells generally appear with a moderate to large amount of cytoplasm compared to the nucleus, preserved cell-cell junctions, and tend to aspirate in clumps, sheets, and tubular-like structures.
What are some typical cell arrangements in epithelial tumors?
Some typical cell arrangements in epithelial tumors are pavement, acinar, honeycomb, papillary, palisade, and trabecular.
From which type of tissue are mesenchymal tumors derived?
Mesenchymal tumors are derived from connective tissue such as fibrous tissue, bone, cartilage, muscular tissue, vascular or adipose tissue.
How do mesenchymal cells generally appear on cytology?
Mesenchymal cells generally have variable forms, ranging from spindle-shaped to fusiform to elongated or more rounded/oval in malignant tumors. The cytoplasm does not have distinct borders, and the cells seem to ‘run off’ into the background.
What is the difference between the suffix ‘-oma’ and ‘-sarcoma’ in tumor names?
The suffix ‘-oma’ is typically used for benign forms of mesenchymal tumors, while the suffix ‘-sarcoma’ is used for malignant forms.
Why is the term ‘soft tissue sarcoma’ used?
The term ‘soft tissue sarcoma’ is used to describe different types of mesenchymal tumors with similar pathological features and biological behavior, including fibrosarcoma, peripheral nerve sheath tumor (PNST), perivascular wall tumor (PWT), myxosarcoma, and liposarcoma.
Why is cytology of mesenchymal tumors challenging?
Cytology of mesenchymal tumors is challenging because cytology alone is not always sufficient to identify the cell type of origin, and special stains are often required for histopathology. This often leads to a diagnosis of ‘soft tissue sarcoma’.
What are the criteria for malignancy in neoplasms?
The criteria for malignancy in neoplasms can be divided into three categories: cellular, nuclear, and cytoplasmic criteria.
What is pleomorphism?
Pleomorphism is a characteristic of malignant neoplasms, referring to marked variation in cell aspects within the same cell population.
What is anisocytosis?
Anisocytosis is an abnormal variation in cell size and shape, and a 2 to 4-fold variation in size is suggestive of malignancy.
What is the significance of disordered cell arrangement in malignant lesions?
Disordered cell arrangement can be seen in malignant lesions, where the arrangement of cells within clusters may be chaotic and disordered, with loss of orderly arrangement between the cells.
What are the nuclear criteria for malignancy?
The nuclear criteria for malignancy include macrokaryosis, anisokaryosis, abnormal multinucleation, nucleolar changes, presence of increased mitotic figures, and chromatin coarsening.
What is cytoplasmic basophilia?
Cytoplasmic basophilia refers to the tendency of the cell cytoplasm to become more basophilic with increased cell activity.
What causes vacuolation in cells?
Accumulation of vacuoles in cells can be caused by abnormal cell protein production or excessive secretory product, often observed in hyperplasia, dysplastic changes, and benign neoplasia.
What is a characteristic feature of atypical mitosis?
Asymmetric mitotic figures, tripolar mitotic figures, and lag chromatin where a fragment of chromatin lags outside the mitotic axis are characteristic features of atypical mitosis, highly suggestive of malignancy.
What is the best way to predict the behavior of tumors?
Histological grading with degree of infiltration
What are some examples of round cell tumors?
Lymphomas, plasma cell tumors, mast cell tumors, histiocytic tumors, transmissible venereal tumors, and well differentiated melanomas
Where are the most common sites for mast cell tumors in dogs and cats?
Skin and subcutaneous tissues
Which form of mast cell tumor is more common in cats?
Visceral form affecting spleen and gastrointestinal tract
What is the recommended diagnostic method for mast cell tumors?
Performing histopathology
What are some cytological features correlated with high grade mast cell tumors in dogs?
Granulation, mitotic index, presence of binucleation or multinucleation, nuclear pleomorphism, and anisokaryosis
What is a histiocytoma?
A common cutaneous neoplasm originating from epidermal dendritic cells
What are some characteristics of histiocytoma aspirates?
Very cellular, high numbers of discrete round cells, variable nuclear to cytoplasmic ratio, and presence of concurrent infiltrate of small lymphocytes
What are some causes of reactive hyperplasia in lymph nodes?
Causes for local reactive hyperplasia include draining of a site with inflammation or neoplasia. Generalized lymphadenomegaly with reactive hyperplasia are seen in cases of generalized skin disease, systemic inflammation (e.g. leishmaniosis, FIV, borreliosis, etc), and in immune mediated disease (e.g. IMPA).
What are the characteristics of high grade lymphoma?
The cytological diagnosis of high grade lymphoma is usually the easiest example, with >50% being large lymphoid cells, with small lymphocytes being in the minority. A high proportion of the large lymphoid cells may have prominent nucleoli and morphology is monomorphic (the population looks uniform, missing the other components of immune stimulation). Lymphoglandular bodies may increase, the mitotic rate is high and mitotic figures may be atypical. Rarely one can also note atypia in the lymphoid cells including binucleated and multinucleated examples, cleaved nucleus and clover head nucleus, cytoplasmic vacuolation and rarely haemophagocytosis.
What are the characteristics of lymphocytic lymphoma?
In lymphocytic lymphoma, there is a clonal expansion of small lymphocytes. These may be difficult to distinguish from their non-neoplastic counterparts, although may be slightly larger with more open chromatin and sometimes have a hand mirror shape with an extension of cytoplasm on one side of the nucleus. A monomorphic population of small lymphocytes with very few plasma cells, lymphoblasts or inflammatory cells (i.e no evidence of reactive change) in a markedly enlarge lymph node, would be suggestive of small cell lymphoma.
What types of lymphadenitis can be observed?
Lymphadenitis may be neutrophilic, eosinophilic, granulomatous, or mixed.
What is neutrophilic lymphadenitis associated with?
Neutrophilic lymphadenitis is seen with bacterial infections, either within the node itself or in the area drained by the node. Bacteria may be seen within neutrophils as well as extracellularly, and neutrophils exhibit degenerative change.
When is eosinophilic inflammation observed in lymph nodes?
Eosinophilic inflammation is seen in association with atopic or parasitic skin disease and the eosinophilic granuloma complex as well as in response to a nearby mast cell tumor. Hypereosinophilic syndrome in cats may involve the lymph nodes.
Which infections are associated with granulomatous inflammation in lymph nodes?
Granulomatous inflammation is seen in mycobacterial, protozoal, and fungal infections as well as idiopathic pyogranulomatous lymphadenitis.
Which other condition can lead to granulomatous lymphadenitis?
Granulomatous lymphadenitis is also noted with lymphadenitis associated with mineral deposition.
What are the causes of increased eosinophil numbers in BAL samples of cats and dogs?
The causes of increased eosinophil numbers in BAL samples of cats include feline asthma, eosinophilic pneumonitis or granuloma, airway parasites (e.g. Angiostrongylus, Aelurostrongylus or Capillaria), systemic hypersensitivity due to external or internal parasites, larval migration of gastrointestinal parasites (Toxocara) and heartworm disease (not common in the UK). In dogs, eosinophil numbers are generally less than 5%.
Which cell populations define pyogranulomatous or mixed cell inflammation?
The presence of active macrophages (multinucleated or deeply vacuolated macrophages) and neutrophils, plus or minus lymphocytes, mast cells, and eosinophils define pyogranulomatous or mixed cell inflammation.
What are some of the causes of pyogranulomatous or mixed cell inflammation in the airways?
Causes of pyogranulomatous or mixed cell inflammation in the airways include severe or chronic airway insult/tissue damage, fungal disease, chronic aspiration pneumonia, lipid aspiration, thromboembolic disease, smoke inhalation, bronchiectasis, and neoplasia.
What evidence suggests previous airway hemorrhage?
Presence of erythrophagocytosis, haemosiderin pigment, or haematoidin crystals suggests previous airway hemorrhage.
Which infections can be identified through cytological diagnosis?
Bacterial, fungal, and pulmonary protozoal infections can be identified through cytological diagnosis.
What are Curschmann’s spirals and what do they indicate?
Curschmann’s spirals are mucus casts of bronchioles, indicating small airway obstruction and/or inspissated and thickened mucus that can occur in obstructive pulmonary disease or asthma.
What can the presence of squamous epithelial cells often coated with a mixed bacterial population indicate?
The presence of squamous epithelial cells, often coated with a mixed bacterial population, can indicate oropharyngeal contamination, which may be seen as secondary to sample contamination or in cases of aspiration pneumonia.
Which infectious agent may be seen as small crescent-shaped tachyzoites?
Toxoplasma gondii may be seen as small crescent-shaped tachyzoites with a small eccentric nucleus in cytological samples.
What are the types of tumors that most frequently metastasize to lymph nodes?
Carcinomas, mast cell tumors, and melanomas.
What does the surrounding lymphoid population resemble in cases of tumor metastasis to lymph nodes?
The surrounding lymphoid population resembles that of a reactive lymph node.
Why is identification of early mast cell tumor metastasis problematic?
Identification of early mast cell tumor metastasis is problematic because small numbers of non-neoplastic mast cells may be found in nodes draining the site of a mast cell tumor, making it difficult to decide if they reflect metastasis or merely reactive change.
What is the main purpose of evaluating body cavity fluids?
The main purpose of evaluating body cavity fluids is to classify them into pure transudate, modified transudate, and exudate, to allow the identification or narrowing of a differential diagnosis list and enable appropriate further diagnostic procedures and management.
What is the recommended sample preparation for body cavity fluid analysis?
Fluid samples should be split between EDTA (for cytology and cell counts), plain tube (for chemistry), and plain sterile tubes (if culture may be needed). Fresh smears should be made if the sample is not processed immediately, and formalin should not be added routinely as it ruins staining for most laboratories.
What parameters should be recorded in the macroscopic appearance of body cavity fluids?
Colour, turbidity, and pH should be recorded in the macroscopic appearance of body cavity fluids.
What can be measured in the supernatant of body cavity fluid analysis?
In the supernatant of body cavity fluid analysis, total protein, albumin, globulin, and other analytes such as creatinine, bilirubin, and lipase can be measured using automated chemistry machines, similar to serum or plasma.
What are the key features of a normal fluid sample (e.g. pleural fluid) in small animals?
A normal fluid sample in small animals usually has low volume, clear straw color, specific gravity (S.G.) of <1.015 to 1.018, total protein of 25-30g/L, and a nucleated cell count of <3 x 10e9/L. Mainly mononuclear cells (mesothelial cells/macrophages) are present, but neutrophils may account for up to 60% of cells.
What is the benefit of using a direct smear with a slide over slide technique?
The benefit of using a direct smear with a slide over slide technique is that it helps in identifying infectious agents that may be trapped in the mucus.
Why is it important to allow smears to dry before placing them in a slide container?
It is important to allow smears to dry before placing them in a slide container to prevent cell condensation, which makes identification more difficult.
Why are cytocentrifuges not routinely available in veterinary practices?
Cytocentrifuges are not routinely available in veterinary practices because most veterinary laboratories use cytospin preparations for low cellularity fluids instead.
What difference did Dehard et al find when comparing cytospin preparations and manual smears of BALFs?
Dehard et al found that cell lysis was more prevalent, cell distribution was more heterogeneous, and neutrophil counts were lower in manual smears compared to cytospin preparations.
What is the recommended temperature for refrigerating BALF fluid?
The recommended temperature for refrigerating BALF fluid is 4 degrees Celsius (4°C).
What is the main purpose of cytological evaluation of respiratory secretions from small animals with tracheobronchial disease?
The main purpose of cytological evaluation is to detect inflammation, confirm suspected infectious organisms, and detect exfoliated neoplastic cells.
What is a major limitation in the cytological interpretation of BALFs?
A major limitation is the lack of uniformity in collection, processing, and reporting of samples, leading to great variation in BALF total and differential cell counts.
What are the normal findings in trachea and bronchi in BALFs?
The normal findings include ciliated, non-ciliated, and mucus producing cells with decreasing numbers of ciliated and mucus producing cells deeper in the airway. Other normal findings include bronchoalveolar macrophages, epithelial cells, and low numbers of inflammatory cells.
What are the most common causes of transudates?
The most common causes of transudates are related to liver disease, heart failure, protein losing nephropathy, and protein losing enteropathy.
At what albumin level do effusions usually begin in animals?
Effusions usually begin at around 14g/L albumin in animals.
What is the macroscopic appearance of transudates?
The macroscopic appearance of transudates is clear, with a specific gravity (S.G.) of less than 1.015 and a total protein level of less than 25g/L.
What is a modified transudate and what are its differentials?
A modified transudate is a longstanding transudate with secondary inflammation/activation of mesothelial cells and extravasation. Its differentials include increased hydrostatic pressure, cardiac failure, hepatic fibrosis, mass lesions compressing vessels, FIP, etc.
What is the macroscopic appearance of modified transudates?
The macroscopic appearance of modified transudates is yellow to serosanguinous or colorless, moderately to trace turbid, with a specific gravity (S.G.) of 1.015 – 1.025 and a variable total protein level of greater than 25g/L.
What are some common causes of exudates?
Common causes of exudates include increased permeability of blood vessels from inflammation, neoplasia, or other diseases of pleural or peritoneal surfaces.
What morphologies of bacteria suggest different species in septic exudates?
Thin fusiform bacteria suggest anaerobes, thin long branching bacteria suggest Actinomyces or Nocardia, cocci suggest Staphylococcus or Streptococcus, and sporulated bacteria suggest Clostridia.
What causes a (non-septic) neutrophilic exudate in body cavity fluids?
Causes of a (non-septic) neutrophilic exudate in body cavity fluids include bile peritonitis and uroperitonitis.
What is a frequent problem encountered with lymph node aspirates?
The fragility of lymphoid cells, alongside the number of times when perinodal fat tissue is aspirated.
Why does the author recommend the non-suction technique for lymph nodes?
Excessive suction can increase the fragility of the cells.
What are some causes of lymph node enlargement?
Reactive hyperplasia, lymphadenitis, lymphoma, and metastatic neoplasia.
What are the different types of cells seen in lymph node aspirates?
Small lymphocytes, intermediate-sized lymphoid cells, large lymphoid cells, plasma cells, macrophages, mast cells, and blood leukocytes.
Describe the characteristics of small lymphocytes.
Slightly larger than red blood cells, with a round nucleus, narrow rim of pale blue cytoplasm, dark staining nucleus with slightly clumped chromatin but no nucleolus.
What are the causes of non-septic exudates?
Causes of non-septic exudates include inflammation of an intracavitary organ, necrosis associated with a poorly exfoliative neoplasm, FIP, etc.
What is the macroscopic appearance of exudates?
Exudates have a turbid appearance and can be red, pink, yellow, or creamy-white.
What are the microscopic findings in exudates?
Microscopically, exudates may contain neutrophils (degenerate or not), macrophages, lymphocytes, eosinophils, mesothelial cells, and in neoplastic exudates, neoplastic cells.
What are the macroscopic appearance and characteristics of F.I.P. fluid?
F.I.P. fluid has a bright yellow/straw-colored appearance, may be viscous, and shows albumin:globulin < 0.4, positive coronavirus titres (>640), and elevated α1 acid glycoprotein.
What are the characteristics of fluids in hemorrhage?
Hemorrhagic fluids have a turbid appearance, specific gravity >1.017, total protein >30g/L, and nucleated cell count (NCC) ranging from 1.5 to 10 x 10^9/L.
What can macrophage uptake of red cells indicate in hemorrhagic fluids?
Macrophage uptake of red cells suggests that the hemorrhage occurred hours to days previously.
What is the predominant cell type in chylous effusion?
The predominant cell type in chylous effusion varies according to chronicity, with small lymphocytes predominant in acute cases and macrophages/neutrophils (non-degenerated) predominant in chronic cases.
What are the causes of chylous effusion?
Causes of chylous effusion include rupture of the thoracic duct, cardiac failure (cat), dirofilariasis (heartworm – dog), diaphragmatic hernia, neoplasm or other mass increasing the hydrostatic pressure of the lymphatic vessels, and idiopathic chylous effusion.
What is the typical microscopic appearance of a peritoneal effusion?
Mixture of neutrophils, lymphocytes, macrophages, and reactive mesothelial cells.
How does the cell count change in a peritoneal effusion over time?
Initially low due to the dilution with urine, but increases with time to become a neutrophilic exudate.
What is the difference between the microscopic appearance of a transudate and an exudate?
Transudate typically has low cellularity, while exudate contains a higher number of cells.
What are the macroscopic characteristics of a peritoneal effusion in the case of bile peritonitis?
Yellow to orange to greenish appearance, moderately turbid to more turbid.
What is the significance of elevated fluid creatinine values in the diagnosis of bile peritonitis?
Fluid creatinine values are higher than blood values in bile peritonitis.
What are the common neoplasms that exfoliate in peritoneal effusions?
Carcinomas in dogs and lymphomas in cats.
What are the normal epithelial cells present in nasal flushes?
Ciliated respiratory epithelial cells.
What are the potential contaminants in airway samples that can affect culture results?
Squamous epithelial cells from oropharynx, inhaled pollen grains, fungal spores, and lab contaminants.
What is the size of tachyzoites?
<1um
What internal structure do bradyzoites have?
Central and radial dots
What type of inflammation is usually associated with this infection?
Neutrophilic inflammation
On which power are lungworms better searched for?
Low power
What kind of cells may be present in samples infected with lungworm?
Inflammatory cells, including variable numbers of eosinophils
In fresh samples, what technique can be rewarding for the detection of living, moving larvae?
Examination of fresh unstained smears
Who should evaluate the sample if there is any doubt about the cytological interpretation?
A cytologist/clinical pathologist
