Equine renal hemangiosarcoma: clinical presentation, pathologic features, and pSTAT3 expression

Abstract

Hemangiosarcoma is an uncommon tumor in horses. We characterized 3 cases of equine renal hemangiosarcoma, focusing on clinical and pathologic features, and describe occurrence of the epithelioid variant of hemangiosarcoma in one of these cases. Nuclear expression of phosphorylated STAT3 (pSTAT3) was assessed to analyze potential inappropriate STAT3 activation as a component of tumor pathogenesis. Clinical signs in the 3 horses included insidious weight loss, followed in one case by serosanguineous nasal discharge and terminal epistaxis, and nonspecific signs of abdominal pain. Two of the hemangiosarcomas had a classical histopathologic appearance; in the other, neoplastic cells were polygonal and were arranged in densely packed sheets, resembling the epithelioid variant. Cross-reactivity of a pSTAT3 antibody was established by demonstration of pSTAT3 expression in the epithelium of glabrous skin by immunoblotting and immunohistochemistry. In the epithelioid hemangiosarcoma, ~40% of neoplastic cells exhibited nuclear pSTAT3 expression, but in the other 2 cases, expression was weak and variable in the neoplastic population, although stromal cell pSTAT3 activity was evident in pulmonary metastases in one case.

Surgical removal and autologous skin grafting as a successful treatment of primary cutaneous haemangiosarcoma in a horse

“…Surprisingly the precious time that has been lost in between diagnosis and treatment did not change the outcome of that case. This observation supports the belief that two different forms of haemangiosarcomas are described: the slowly progressive and the aggressive rapidly growing form (Hughes et al, 2018;Johns et al, 2005).…”

Haemangiosarcoma in two full sibling American Quarter Horse geldings

“…; Hughes et al . ), but to our knowledge, this is the first report describing bilateral primary renal haemangiosarcoma in a horse.…”

Treatment of congenital atypical haemangiosarcoma in a foal

“…The clinical presentation of these tumours is highly dependent on the wide variety of possible locations (Beaumier et al, 2020; Hughes et al, 2018; Segabinazzi et al, 2021). Haemangiosarcomas vary in size and can be solitary but are often multiple.…”