Primary Uterine Hemangiosarcoma in a Thoroughbred: A Case Report.

This research reports on the first known instance of uterine hemangiosarcoma, a type of cancer, in a horse. The mare, a 1.8-year-old Thoroughbred filly, was investigated for unexplained blood discharge and severe abdominal pain, which eventually led to a diagnosis of the cancer, a surgery, and then euthanasia due to complications.

Case Presentation and Initial Diagnosis

• The paper discusses the case of a young Thoroughbred filly that was presented for an examination following unexplained vaginal bleeding and severe abdominal pain.
• Physical examination, involving a transrectal palpation, revealed an asymmetrical uterus. An ultrasonographic study of the area highlighted a large, irregularly shaped mass near the filly’s cervix.
• During the examination process, the mare expelled a uterine mass through her vulva, furnishing the vets with an opportunity to conduct further investigation into the unusual medical case.

Histological Analysis and Final Diagnosis

• The expelled mass was subjected to histological and immunohistochemical examinations, adopting the use of CD31 and Factor VIII markers.
• These detailed analyses led to an initial diagnosis of hemangiosarcoma – a malignant tumour of the blood vessels. This finding necessitated a therapeutic hysterectomy (removal of the uterus).
• Further analysis of the removed uterine tissue corroborated the earlier diagnosis of hemangiosarcoma.

Postoperative Complications and Necropsy

• Despite the successful surgical removal of the uterine tumour, the mare’s condition worsened over the ensuing two weeks.
• Complications following the surgery led to the decision to euthanize the filly.
• A necropsy (post-mortem examination) conducted on the mare discovered intestinal adhesions at the site of the surgical incision, responsible for the postoperative difficulties.
• Importantly, no additional tumours were discovered during the necropsy, confirming that the uterine mass was indeed the primary tumour, making this the first reported case of primary uterine hemangiosarcoma in the horse.