Epithelioid variant of haemangiosarcoma in a gelding

Summary This case report provides a clinical description of an epithelioid variant of haemangiosarcoma in a horse. Haemangiosarcomas are rare neoplasms in equids, and only recently have the pathological aspects of the epithelioid variant in horses been described. Despite performance of cytology and surgical biopsy, the ante mortem diagnosis was incorrect in this case, demonstrating the common problem with diagnosing this neoplasm due to the lack of overt vascular differentiation. Due to the deteriorating condition of the patient, no antineoplastic treatment was attempted. A post mortem computed tomography helped characterise the invasive nature of the tumour. Only with post mortem sampling was the diagnosis of epithelioid variant of haemangiosarcoma discovered.