Intraoral cytology - DVM
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Intraoral cytology
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Summary of microscopic findings

Inflammatory cells (neutrophils, macrophages)

> 85% neutrophils = suppurative

< 50% macrophages = active pyogranulomatous

> 50% macrophages = chronic pyogranulomatous

> 10% eosinophils = eosinophilic

Tissue cells

  • Malignant if more than three of the malignant criteria listed above are present
  • Epithelial (clusters, clumps) = carcinoma or adenocarcinoma (Photos 10A and 10B)
  • Mesenchymal (single, spindly) = sarcoma (Photos 11A and 11B)
  • Round cell, mast cell, melanoma, plasma cell (Photos 12A and 12B)

Photo 10A: A swollen and inflamed area surrounding a previously extracted canine in a 13-year-old Poodle.

Photo 10B: Cytologic examination of a sample is consistent with carcinoma (squamous cell).

Photo 11A: A mandibular mass in 10-year-old Rottweiler.

Photo 11B: The aspirate reveals osteosarcoma. Two mitotic figures as well as eosinophilic material consistent with osteoid are shown. The large, multinucleated cell is an osteoclast. (Photomicrograph courtesy of Dr. Rebekah Gunn-Christie.)

Photo 12A: A palatal mass in a 13-year-old mixed-breed dog.

Photo 12B: Cytologic examination of a sample reveals round cells with multiple criteria of malignancy as well as pigment consistent with oral melanoma.

Photo 12C: The same oral melanoma case in Photos 12A and 12B sampled in an area of inflammation. Note the inflammatory and neoplastic cells.
Mixed population = inflammatory and tissue cells (Photo 12C)

The author thanks Rebekah Gunn-Christie, DVM, Dipl. ACVP, for years of cytologic help as well as review of this manuscript.

Suggested reading

  • Sugerman, PB, Savage NW. Exfoliative cytology in clinical oral pathology. Aust Dent J 1996;41(2):71-74.
  • Sirois M. Cytology and urinalysis. Principles and practice of veterinary technology. St. Louis, Mo: Mosby, 2004.
  • Cowell R, Tyler R, Meinkoth J. Diagnostic cytology and hematology of the dog and cat. 3rd ed. St. Louis, Mo: Elsevier, 2008.
  • Baker R, Lumsden J. Color atlas of cytology of the dog and cat. St. Louis, Mo: Mosby, 2000.
  • Raskin R, Meyer D. Atlas of canine and feline cytology. 2nd ed. Philadelphia, Pa: WB Saunders, 2010.


Source: DVM360 MAGAZINE,
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