Osteoclastic-like giant cell tumour in a cat

Area of Science:

• Veterinary Medicine
• Oral Pathology
• Oncology

Background:

• Epulis, a common oral tumor in cats, can present diagnostic challenges.
• Understanding the cellular composition and origin of feline epulis is crucial for effective treatment.

Observation:

• A case of an 11-year-old domestic shorthair cat with a gingival epulis is presented.
• The mass was surgically excised and characterized by a large number of multinucleated giant cells (MGCs).
• Radiography revealed no signs of bone invasion.

Findings:

• Histopathology confirmed the presence of MGCs, mononuclear mesenchymal cells, and mitotic activity.
• Tartrase-resistant acid phosphatase (TRAP) staining indicated osteoclast activity in MGCs.
• Immunohistochemistry showed proliferating-cell nuclear antigen (PCNA) in mononuclear cells, suggesting proliferation.

Implications:

• The diagnosis of an osteoclast-like giant cell tumor was made, likely originating from periosteal tissue.
• Surgical excision resulted in an uneventful recovery with no recurrence observed for three years.
• This case highlights the importance of histopathological and immunohistochemical analysis for accurate diagnosis and prognosis of feline oral tumors.