A poorly-differentiated hepatic haemangiosarcoma in an Amazona farinosa parrot

A poorly-differentiated hepatic haemangiosarcoma was found in a 25-year-old Amazona farinosa parrot which had died because of massive internal haemorrhage due to its rupture. The case history indicated that in recent years the parrot had been subjected to long periods of treatment with testosterone for problems of feather loss and psychogenic pruritus. Histologically, the neoplasm was characterized by two components; angiomatous areas showing irregular vascular channels and solid, poorly-differentiated areas, showing sheets of spindle-shaped or undifferentiated cells interposed with necrotic material. Immunohistochemical techniques with different tumour markers were applied in order to determine the histogenesis of the tumour cells and their positive immunoreaction to vimentin and Von Willebrand Factor (Factor VIII), considered a specific marker for endothelial tumours, confirmed the diagnosis of haemangiosarcoma. The author suggests a possible hormone-dependent origin of this hepatic vascular tumour.