Hemangiosarcoma in 11 Young Horses

Abstract

Hemangiosarcoma is a rare neoplasm of horses and hemangiosarcoma in young horses might behave differently than in mature horses. The purpose of this study was to identify the characteristics of hemangiosarcoma occurring in horses < or = 3 years of age. Medical records from 1982 to 2004 were searched for horses < or = 3 years of age with a histopathologic diagnosis of hemangiosarcoma. Eleven records were identified. Thoroughbred and Thoroughbred crosses predominated. Age ranged from 9 days to 3 years. All horses presented with cutaneous or leg swellings or joint effusion. Physical examination findings included tachycardia, fever, and depression. Laboratory abnormalities included anemia (5/11), hyperfibrinogenemia (4/11), hypofibrinogenemia (3/11), thrombocytopenia (2/11), and neutrophilic leukocytosis (1/11). Ultrasonographic and radiographic evaluation was not diagnostic in any case. Antemortem histopathologic diagnosis was obtained in 10 cases. Six of 11 horses were euthanized. Surgical resection was performed in 5 horses, 2 of which were later euthanized. Diagnosis was confirmed histologically at postmortem examination in all euthanized horses. Two cases resolved spontaneously. Early histopathologic diagnosis may allow cure if the mass is localized and amenable to surgical resection. In cases where the horse is medically stable, and masses are not interfering with quality of life, a period of observation may be warranted.

Primary haemangiosarcoma in the proximal humerus of a Clydesdale gelding

“…There are several reports of vertebral and spinal cord compression due to haemangiosarcoma (Kiupel et al 2000) without evidence of disseminated disease (Newton-Clarke et al 1994;Berry 1999;MacGillivray et al 2003). Although there are reports of soft tissue haemangiosarcomas infiltrating the osseous tissue in distal limbs (Johns et al 2005) and axial skeleton (Sweeney and Gillette 1989), to the authors' knowledge, a primary osseous haemangiosarcoma in the long bone of a horse has not been reported previously.…”

“…No breed or sex predilection has been reported (Southwood et al 2000). Haemangiosarcomas may be occur as focal masses, masses with local infiltration, internal masses restricted to one organ or disseminated neoplasia affecting multiple organs (Southwood et al 2000;MacGillivray et al 2003;Johns et al 2005;Ladd et al 2005) and generally present with clinical signs referable to the body system affected.…”

“…The occurrence of haemangiosarcomas in the musculoskeletal system is well documented. It is the most common primary body system affected in young horses (Johns et al 2005) and is often involved in cases of disseminated haemangiosarcoma in older horses (Southwood et al 2000). Musculoskeletal involvement often results in lameness and intramuscular swellings that often have clinical and ultrasonographic findings consistent with haematoma formation (Collins et al 1994;Southwood et al 2000;Johns et al 2005).…”

“…Treatment for haemangiosarcoma in all species is generally considered unrewarding and considered palliative rather than curative (Southwood et al 2000;Johns et al 2005;Hidaka et al 2006). Reported treatments include surgical removal, radiation therapy, chemotherapy (e.g.…”

“…Haemangiosarcomas are malignant neoplasms originating from vascular endothelial cells. In horses, haemangiosarcomas are uncommon, although involvement of the musculoskeletal system (Valentine et al 1986;Kiupel et al 2000;MacGillivray et al 2003;Johns et al 2005), skin (Dunkel et al 2004), central nervous system (Ladd et al 2005), respiratory tract (Frye et al 1983;Southwood et al 2000) and ocular adnexa (Sansom et al 2006;Gearhart et al 2007) has been described.…”