Malignant Glomus Tumour (Glomangiosarcoma) with Additional Neuroendocrine Differentiation in a Horse.

This study examines the case of a 13-year-old mixed-breed horse suffering from head shaking and chewing difficulties due to a slow-growing tumour in the maxilla region of its mouth. Despite chemotherapy treatments, the horse’s condition did not improve and it had to be euthanized. The tumor was later identified as a unique variant of malignant glomus tumour having both vascular spaces and neuroendocrine differentiation.

Objective of the Research

• This study focused on diagnosing and examining the manifestation of a unique malignant glomus tumor in a horse. Given its novel expression with neuroendocrine differentiation, the study aimed to contribute to the veterinary knowledge base about such rare malignancies.

Background of the Case

• The subject of the study was a 13-year-old Icelandic crossbred horse.
• The notable symptoms observed in the horse were headshaking and impairment in chewing.
• Examinations revealed a slowly growing mass located in the anterior maxilla, an area in the upper jaw.
• The tumor caused destruction of the alveolar bone and the roots of the horse’s incisors.
• Nodular proliferations, or abnormal growths, also affected the nasal septum and conchae.

Treatment and Outcome

• The horse was treated with chemotherapy, but there was no favorable response.
• The disease’s progression led to the decision to humanely euthanize the horse.
• Post-mortem analysis classified the mass as a malignant glomus tumor, with unusual characteristics.

Findings and Conclusion

• The tumor was distinctive due to its multifocal vascular spaces along with an additional neuroendocrine differentiation. This type of tumor and unique expression has never been previously documented in an animal.
• These findings suggest that veterinary professionals should consider rare and unique manifestations of common tumors.
• Continuing research could reveal more about such tumors, aiding in their diagnosis and potentially leading to more effective treatments.