Intestinal myxosarcoma in a thoroughbred mare

Area of Science:

• Veterinary oncology
• Equine gastrointestinal pathology

Background:

• Chronic colic and weight loss are common presenting complaints in horses.
• Intestinal masses can cause partial or complete obstruction.

Observation:

• A large, fibrotic mass was found at the cecal base during abdominal surgery.
• The mass protruded into the intestinal lumen, causing partial obstruction.
• The mass contained shiny, gelatinous material and was not surgically resectable.

Findings:

• Histological examination revealed atypical fibroblastic cells and a mucinous stroma.
• Alcian blue staining identified large spaces filled with mucopolysaccharides.
• The tumor invaded locally and metastasized to regional lymph nodes, confirming a diagnosis of myxosarcoma.
• This represents the first documented case of a myxomatous tumor in the equine intestinal tract.

Implications:

• This case expands the known spectrum of tumors affecting the equine digestive system.
• Highlights the importance of considering rare neoplastic conditions in horses with chronic gastrointestinal signs.
• Further research into equine intestinal neoplasms is warranted.