Cytology Review - NAVLE book Flashcards
Gram Stain
Used to classify bacteria
Gram (+) bacteria have teichoic acid in cell walls - Stain deep blue
Gram (-) bacteria have LPS in cell walls - Counterstained with Safranin or Fuchsin which stains red
Romanowsky Type Stain
Use on air-dried specimens
Aqueous based stains
Ex: Wright’s, Giemsa, Wright’s Giemsa, Leishman’s, Diff-Quik, DipStat
New Methylene Blue Stain
Aqueous Stain
Poor Cytoplasmic Detal - Excellent Nuclear & Nucleolar Visualization
Use for detection of: Nucleated cells, bacteria, fungi, yeast, NRBC’s, urine sediment (Sedi-Stain)
Used to count reticulocytes
Immunocytochemical Stains
Use antibodies against epitopes such as clusters of differentiation (CD antigens) to identify the cell line of origin
Limited by antibodies available
Neutrophils
13-16um in diameter
3-5 nuclear lobes
Females: occasionaly have Barr body (looks like small drumstick on end of one nuclear lobe)
Clear cytoplasm - dogs, cats, horses
Pink cytoplasm - ruminants
Macrophages
Medium-to-large sized - often > 25 um
Round to pleomorphic nuclei
Different morphologies:
a. Mononuclear: variable vacuolated
b. Epitheliod: Smooth blue cytoplasm w/ eccentric nucleus
c. Multinucleated giant cell
Eosinophils
13-16 um
3-5 nuclear lobes
Variable # of granules
Granules rod-shaped in cats
Lymphocytes
7-13 um
Single round nucleus
Uniformly high nucleus-to-cytoplasm (N:C) ratio
Plasma Cells
9-15 um long
Ovoid shaped
Eccentric Nucleus
Dark blue cytoplasm (d/t abundance of RER)
Perinuclear pale to clear zone (“halo”)
Mott Cells
Plasma Cells that are congested with Ig
Ig is contained withing pale blue structures called “Russell bodies”
Suppurative/Neutrophilic/Purulent Inflammation
Suggests active and likely acute process (but can be chronic)
Mainly bacterial infections
Degenerate neutrophils occur when neutrophils are exposed to toxic environment & KILLED rather than going to apoptosis
Karyolysis: Indistinct nucleus, cytoplasmic margin still intact
Pyknosis: Condensation & coalescing of nucleus into single dark, hyperchromic structure
Karyorrhexis: fragmentation/pyknosis of nuclear lobes
Eosinophilic Inflammation
When eosinophils are greater than 10% of overall inflammatory cell population
Consider:
- Allergic & Hypersensitivity Rxns
- Parasitic Infestation
- heartworm disease, Tissue migration of Dirofilaria immitis (cats), flea bite allergy - Fungal infection
- Cryptococcus neoformans in the CNS - Neoplasia
- Mast cell tumor, lymphoma
Granulomatous / Pyogranulomatous Inflammation
Consider:
- Foreign Body
- Fungal Infection
- Higher bacteria (e.g. Nocardia, Actinomyces, Mycobacterium)
Lymphocytic and/or Plasmacytic Inflammation
- Allergic rxns (e.g. vaccination sites)
- Viral infection
- Can be ass’d w/ chronic inflammation
- Nonspecific antigenic stimulation (e.g. IBD)
Mesenchymal Cells
Examples of mesenchymal cells: fibroblasts, osteoblasts, chondroblasts
Vary in shape: ovoid, stellate, fusiform, spindle, elongate
Can form disorganized clumps; NEVER form organized cohesive sheets
Epithelial Cells
Ex: Squamous cells, salivary epithelium, GI mucosa, hapatocytes, renal tubular cells
Vary in shape: round, angular, caudate to polygonal, can be spindle shaped
Form organized, cohesive sheets (as well as disorganized clumps)
Glandular epithelial cells will occasionally form acinar or rosette arrangement
Photo: Transitional Cell Carcinoma
Round Cell Type 1: Lymphocytes
Small, round w/ round nuclei
High N:C ratio
Nuclei display finely stippled chromatin pattern
Immature cells larger w/ open less intensely staining chromatin pattern
Lymphoblasts will have nucleoli
More immature lymphocytes = more likely they are malignant
Round Cells Type 2: Transmissible Veneral Tumor (TVT)
Canine Only: Found on prepuce, vulva, nose
Nuclei have clumped chromatin
Often 1-2 nucleoli
Moderate amounts of pale blue cytoplasm w/ distinct peripherally located vacuoles
Many mitotic figures usually seen w/ TVT
Round Cells Type 3: Plasma Cells
Generally round to ovoid
Nucleus often has coarsely clumped chromatin (“clockfaced” or “pinwheel”)
Almost always have distinct, prominent, pale-staining, perinuclear clearing area - this represents the Golgi zone (profound Ig production here)
Plasmacytomas usually benign (photo below)
Round Cell Types 4: Benign Cutaneous Histiocytoma
Canine only: young animals
Medium sized round cells
Fine chromatin pattern in nuclei; moderate pleomorphism; moderate amount of pale cytoplasm with distinct margins
Cytoplasm so pale that halo is only seen around nucleus
Round Cell Types 5: Mast Cell Tumor
Well-differentiated mast cells have abundant, small, dark purple granules that often obscure round nucleus
Granules will occasionally stain poorly with aqueous stains (e.g. Diff-Quik) - can use Toluidine blue or Giemsa
May see eosinophilic inflammation
Round Cell Types 6: Neuroendocrine Tumors
Cells look similar for all members (e.g. adrenal gland, beta cells of pancreas, thyroid epithelium, cells from a chemodectoma)
Numerous round, bare nuclei closely associated with one another in a bacground of cytoplasm, with rare intact cells
Rare intact cells: pale cytoplasm with indistinct margins
Anisokaryosis
Variability in the size of the nuclei
Anisocytosis
Different sized cells
Mitotic Figures
Abnormally high numbers or presence of bizarre ones
