Hemangiosarcoma with widespread metastasis that originated on the metatarsal pad of a Java sparrow (Padda oryzivora)

A five-year-old male Java sparrow (Padda oryzivora) was examined because of the appearance of a purple spot approximately 1 mm in diameter on the right metatarsal pad. Seven months later, the spot spread to the entire right leg, and the bird died. At necropsy, multiple neoplastic masses on the right leg reached up to the pelvic cavity. There was one similar mass on the right kidney and multiple red spots on the liver. Histopathological examination revealed that neoplastic cells proliferated solidly or formed abundant irregular blood vessels. Watanabe silver staining revealed that neoplastic cells were surrounded by argentophil fibers. Immunohistochemically, the neoplastic cells were positive for anti-human von Willebrand factor antibodies. This is the first report of hemangiosarcoma in a finch.