Ocular angiosarcoma in a pony ‐ MRI and histopathological appearance

Abstract

Summary Ocular angiosarcomas are an infrequent aetiology of exophthalmus in the horse. In the case presented here, a pony was referred with a history of supraorbital swelling, exophthalmus and conjunctivitis of the right eye. Radiographic and ultrasonographic examinations were used for diagnosis; however, the exact definition of the retrobulbar changes could only be made by magnetic resonance imaging (MRI). MRI shows anatomic and physiological detail in both the osseous and soft tissue structures. Only 3 sequences were used in this case: a transverse T2‐weighted and a dorsal high resolution, T1‐weighted gradient echo with multiplanar reconstruction capability pre‐ and post contrast application. This case report suggests that MRI should be used more frequently in the diagnosis of head tumours in horses.

Equine orbital disease: A review

“…This tumour is a secondary neoplasm and as such the prognosis is generally poor despite early diagnosis due to systemic spread (Taintor and Schleis 2011). Other tumours previously documented in the equine orbit include angiosarcoma, haemangiosarcoma, melanoma, medulloepithelioma, fibroma, malignant rhabdoid, meningioma and adenocarcinoma (Eagle et al 1978;Bistner et al 1983;Bolton et al 1990;Hong et al 1999;Colitz et al 2000;Moore et al 2000;Davis et al 2002;Bischofberger et al 2008;Naylor et al 2010).…”

Equine periocular neoplasia: Current concepts in aetiopathogenesis and emerging treatment modalities

“…Study design varies widely and may be limited to isolated case reports (Moore et al 2003;Bischofberger et al 2008). Identical treatments administered to similarly-appearing tumour types can have different clinical outcomes.…”

Presumed primary ocular lymphangiosarcoma with metastasis in a miniature horse

“…Angiosarcomas are malignant vascular tumors historically classified as hemangiomas, hemangiosarcomas, or lymphangiosarcomas based on the cell of origin. However, when the malignant cell of origin cannot be determined, the neoplasms are diagnosed as angiosarcomas . Immunohistochemistry (IHC) for endothelial cell markers is often needed to identify the cell of origin and diagnose angiosarcomas, and even then, some appear to have a mixed origin…”

“…However, when the malignant cell of origin cannot be determined, the neoplasms are diagnosed as angiosarcomas. [1][2][3][4][5][6][7][8][9][10] Immunohistochemistry (IHC) for endothelial cell markers is often needed to identify the cell of origin and diagnose angiosarcomas, and even then, some appear to have a mixed origin. 11 Lymphangiosarcomas originate from endothelial cells of lymphatic vessels and, although relatively rare, this tumor has been reported in numerous dogs and cats, with no primary ocular cases reported in these species.…”