Oral Masses in Two Cats

• Published in: Veterinary pathology Vol. 48; no. 4; pp. 906 - 910
• Main Authors: Bock, P., Hach, V., Baumgärtner, W.
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01.07.2011
• Subjects: Animals; Cat Diseases - pathology; Cat Diseases - surgery; Cats; Diagnosis, Differential; Female; Male; Mandibular Neoplasms - pathology; Mandibular Neoplasms - surgery; Mandibular Neoplasms - veterinary; Maxillary Neoplasms - pathology; Maxillary Neoplasms - surgery; Maxillary Neoplasms - veterinary; Odontogenic Tumors - pathology; Odontogenic Tumors - surgery; Odontogenic Tumors - veterinary; odontogenic ameloblast-associated protein; oral masses; immunohistochemistry; cat; amyloid-producing odontogenic tumor
• ISSN: 0300-9858; 1544-2217
• DOI: 10.1177/0300985810381243

Incisional biopsies from the oral cavity of 2 adult cats were submitted for histological investigation. Cat No. 1 showed a solitary well-circumscribed neoplasm in the left mandible. Cat No. 2 demonstrated a diffusely infiltrating neoplasm in the left maxilla. Both tumors consisted of medium-size epithelial cells embedded in a fibrovascular stroma. The mitotic index was 0 to 1 mitosis per high-power field. The epithelial cells showed an irregular arrangement forming nests or streams in cat No. 1, whereas a palisading growth was noted in cat No. 2. Both tumors, especially that of cat No. 1, showed multifocal accumulations of amyloid as confirmed by Congo red staining and a distinct green birefringence under polarized light, which lacked cytokeratin immunoreactivity as well as and AL and AA amyloid immunoreactivity. In addition, the amyloid in cat No. 2 was positive for the odontogenic ameloblast-associated protein, formerly termed APin. In sum, both cats suffered from an amyloid-producing odontogenic tumor, but their tumors varied with respect to morphology and type of amyloid produced.