Gingival Fibrosarcoma in a Horse.

The research paper presents the case of a 4-year-old mare successfully treated for a rare type of oral cancer, fibrosarcoma, through surgery and chemotherapy. Despite initial treatment failure and tumor recurrence, continued aggressive treatment resulted in no further regrowth three months post final treatment, and the horse remained tumor-free almost five years later.

Case Background and Presentation

• The study focuses on a case of a 4-year-old thoroughbred cross mare that was referred to the University of Edinburgh Veterinary School Equine Hospital.
• The horse had a soft tissue tumor on the buccal gingival margin of the rostral right maxillary cheek teeth, an unusual location for equine oral tumors.
• This tumor was initially removed through surgical resection, and a histopathology examination confirmed it as a fibrosarcoma, a type of rare oral cancer which is aggressive and recurrent.

Treatment and Outcomes

• After surgical excision of the tumor, a supportive treatment regimen using intralesional cisplatin chemotherapy was started.
• Despite these interventions, the tumor recurred, prompting additional rounds of intralesional cisplatin injections and surgical resections.
• The aggressive treatment was carried out over a span of 14 weeks. While the tumor initially showed a poor response to treatment, no further regrowth was observed three months after the last treatment session.
• Remarkably, the horse remained free of visible evidence of the tumor for almost five years post-treatment, highlighting the success of the chosen treatment approach.

Significance of the Study

• Despite the rarity and aggressive nature of fibrosarcoma tumors, this study provides positive implications for the effective treatment of such tumors in horses.
• This case demonstrates how combined strategies of surgery and chemotherapy can effectively manage and ultimately eliminate tumor recurrence.
• While the initial responses to treatments were poor, persistence with aggressive therapeutic strategies led to the complete absence of tumor regrowth, highlighting the importance of adhering to treatment strategies even when initial results may not be promising.