Cytological Examination: Part II Clinical Pathology

Microscopic Evaluation Scan at 10x Determine if stained adequately Any localized or increased cellular areas Scan for any large objects: parasites, foreign bodies, etc. Look at what type of cells are found Examine at 40x Evaluate individual cells Examine at 100x (oil immersion) Cell morphology, nucleus, chromatin, cytoplasm

Interpretation Inflammatory vs. Non-inflammatory Most important judgement May not get a definitive diagnosis, but may be able to get a general idea/general process. Cytology may be helpful on what’s the next diagnostic step to take Culture Biopsy Rads Serology

Inflammatory cells found in Cytology Neutrophils May resemble same as blood neutrophils. Be degenerative Hypersegmented Lymphocytes Plasma cells Active lymphocytes that have a very basophilic cytoplasm Eosinophils Mast cells- allergic inflammation Macrophages Large tissue monocytes. Have abundant blue cytoplasm with vacoules that may contain phagocytized cells or debris Oval to pleomorphic nucleus Mesothelial cells Cells that line the pleural, peritoneal,a nd visceral surfaces. A type of macrophage

Neutrophils in Tissue

Lymphocytes and Plasma cells in tissue

Eosinophils in tissue

Mast cells in tissue

Macrophages in Tissue

Mesothelial Cells in Tissue

Classifications of Inflammation Purulent Pyogranulomatous Granulomatous Eosinophilic May also be classified as duration: Acute Subacute Chronic-active Chronic

Purulent Inflammation (Abscess) Most common type of inflammation Usually caused by bacteria Also called suppurative inflammation Over 70% neutrophils with a few macrophages and lymphocytes

Pyogranulomatous inflammation Also referred to as chronic/active Consists of macrophages and 50-75% neutrophils

Granulomatous Inflammation Greater than 50-70% of cells are mononuclear (monocytes, macrophage, giant cells). Few neutrophils Also called chronic inflammation.

Eosinophilic Inflammation Consists of greater than 10% eosinophils Allergic related May see a few mast cells, plasma cells and lymphocytes

Selected Infectious agents of Cutaneous lesions Bacterial agents Tend to produce lesions characterized by >85% neutrophils, few macrophages, lymphocytes, and plasma cells. Rods, cocci Cytology is helpful in determining what kind of culture or stain is needed. Fungal agents Tend to have more macrophages than bacterial lesions, but may be mixed (pyogranulomatous). Low numbers of lymphocytes. Sporothrix schenkii Histoplasma capsulatum Blastomyces dermatidis Crytococcus neoformans Coccidiodes immitis

Sporiotrichosis: Sporothrix schenkii Organisms are round to oval or cigar shaped Stain pale to medium-blue cytoplasm with a slightly eccentric pink or purple nucleus. Dimorphic fungus found in the environment worldwide Inoculated into tissue via puncture wounds Suppurative to pyogranulamatous Skin lesions are characterized by multiple, non-painful, nonpruritic nodules that may ulcerate and drain purulent exudate. Dissemination is rare

Sporotricosis continued Diagnose via cytology, biopsy, fungal culture Easier to diagnose in cats, tend to have more organisms Infected cats are highly contagious to humans Treatment includes long term antifungals Ketoconazole Itraconazole Prognosis is fair to good, but relapse is possible.

Histoplasma Capuslatum Round to oval- yeast-like Dark blue/purple staining nucleus surrounded by a thin halo Causes systemic disease Cutanous lesions are rare, causes lungs or GI tract infections Most common in termperate and subtropical areas. Diagnosed through cytology, histopathology, fungal cultures, rads

Blastomyces dermatidis: Blatomycosis Caused by inhaling the conidia Causes a disseminated infection Lymph nodes Skin Bones Other organs Found in mostly acidic soils Diagnosed by cytology, histopathology, serology and fungal cultures. Most are single, blue, spherical and thick walled. Pyogranulamatous

Cyptococcus Neoformans: Cryptococcosis Found worldwide Organism is inhaled and establishes infections in the nasal cavity, sinuses, skin and other organs Spherical, yeast-like organisms Thick, clear mucoid capsule May be budding or non-budding Cats: URI signs, SQ swelling over bridge of nose, non-painful, may have CNS signs Dogs: CNS signs and ophthalmic signs usually occur. Nodules on lips and nose.

Coicidiodes Immitis: Coccidiomycosis Dimorphic fungus and soil saprophyte endemic to desert areas Organisms are inhaled and disseminate in body Skin lesions are nodular, abscesses and draining tracts Painful lameness

Coccidiomycosis Continued Spherical with thick deeply stained wall. Diagnosis thought cytology, pyogranulamatous, histopathology, serology and fungal culture. Treated by long term systemic antifungals (8-12 months) Prognosis is unpredictable Relapses are common Fungal cultures are contagious Infected animals are not considered contagious

Leishmania donovani: Leishamaniasis Protozoa transmitted by blood-sucking sandflies Endemic to Central and South America Sporadic infections in the US A visceral and cutaneous disease that develops over months-years Lesions are dark and small to large and ulcerated. Diagnose by imprints, scraping and FNA Organism usually found in macrophages Small, round to oval Has a very light blue cytoplasm, an oval nucleus, and a small dark kinetoplast Usually numerous organisms found Not curable Contagious to other dogs through vector

Non-inflammatory Lesions Neoplastic Epithelial Mesenchymal (spindle cell) Discrete Round cell tumor Non-Neoplastic Cysts (sebaceous) Hyperplasia (prostatic hyperplasia) Dysplasia Hematomas Seromas Salivary Mucocele

Epithelial Neoplasms Tend to exfoliate cells in sheets or clumps Cells tend to be large with moderate to abundant cytoplasm Benign epithelial tumors Papilloma Epidermal inclusion cyst (epithelioma) Perianal gland adenomas Malignant epithelial tumors Perianal gland adenocarcinoma Squamous cell carcinoma

Mesenchymal tumors: Spindle cell tumors Tend to exfoliate individual cells instead of clusters May be difficult to differentiate from normal granulation tissue (spindle cells are plump). Difficult to differentiate from the different types of tumors on cytology. Benign forms: Fibromas Lipomas Hemangioma Malignant forms: Fibrosarcoma Liposarcoma Hemangiosarcoma

Discrete Round Cell Tumors Tend to exfoliate small to medium sized cells. Also called cutaneous round cell tumors Types: Mast cell tumors Cutaneous lymphosarcoma Histioctyomas Transmissable venereal tumor

Evaluation of Malignant Potential (Criteria of Malignancy) Variation of cell size Variation in nuclear size Multinucleated Increased nucleus: cytoplams ratio Mitotic figures Variation in nucleolar size/shape Coarse Chromatin pattern If more than 3 criteria are recognized in a high percentage of cells, this is strong evidenc for malignancy If 1-3 criteria are present, may be either benign or malignant and should be sent to pathologist or biopsied.

Submission of Cytologic Slides Send 2-3 air-dried unfixed smears and 2-3 stained smears Fluid samples should have smears prepared from them immediately Also send EDTA and red top tubes filled with fluid Mail in protective containers Timely transportation service Easy accesible and easy to collect cytology Tranquilization/anesthesia seldome needed for sample collection Quick-sample can be prepared, stained, and microscopically evaluated in minutes.