Oral metastasis of renal cell carcinoma in a horse.

The research is about a 14-year-old horse that had an oral metastasis of renal cell carcinoma, which was identified by undergoing various treatments and clinical procedures, including biopsy, surgical excision, and radiotherapy.

Initial Presentation and Diagnosis

• The horse, a hunting horse of significant age, presented with an ulcerated mass located on the left premaxilla, which is the portion of the horse’s upper jaw or maxilla in front of the canine teeth.
• The first step in diagnosing the condition involved taking a biopsy of the mass. It was revealed to be a poorly differentiated carcinoma, a type of cancer that starts in the cells that line the body and cavities inside organs.

Initial Treatment and Recurrence

• With the diagnosis established, an attempt was made at surgical excision – a common method of removing a tumor.
• Unfortunately, some months after this surgery, local regrowth of the carcinoma was observed, indicating that the initial surgery had not successfully removed all cancerous cells.

Secondary Treatment and Subsequent Deterioration

• Following this recurrence, radiotherapy was performed to try to control the spread of cancer cells. An initial improvement in the condition was seen after this treatment.
• However, the horse eventually experienced marked deterioration in its health, indicating the spread of the cancer despite the application of radiotherapy.

Post-Mortem Findings

• The worsening condition of the horse led to the compassionate decision to euthanize it. A post-mortem examination was conducted to understand the full extent of the disease and its impacts on the horse’s body.
• The examination revealed an enormously enlarged right kidney, illuminating a primary site of cancer. The spread of metastases, or secondary cancer growths, was also observed to be widespread in the body.
• A more detailed histological examination, involving the study of the microscopic structure of tissues, identified the disease as a metastatic clear cell renal carcinoma. This type of cancer originates in the kidney and can spread (metastasize) to other parts of the body, including in this case, to the oral area.