title: Giant cell tumor of the bone in a scarlet macaw (Ara macao).
abstract: A 6-mo-old female scarlet macaw (Ara macao) was presented after a 2-mo period of anorexia and weakness. The bird was reluctant to fly 1 wk before referral due to a painful left wing. Physical examination revealed a firm swelling around the left shoulder. On radiographs, the diaphysis and proximal metaphysis of the left scapula were radiolucent. Computer tomography revealed an osteolytic process, suggestive of a bone tumor, affecting the left scapula. Cytology of a fine needle aspiration biopsy of the mass showed erythrocytes, a proliferation of spindle-shaped mesenchymal cells, and multinucleated giant cells (osteoclasts) suggestive of a giant cell tumor. The left wing, including the scapula, was amputated. The bird showed a fast recovery but died 1 hr later. Findings during the pathological examination were compatible with shock due to blood loss. The shoulder process was characterized as a giant cell tumor. To our knowledge, this is the first complete report of a giant cell tumor of the bone in a bird.
authors.affiliation: Division of Avian and Exotic Animal Medicine, Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Universiteit Utrecht, Utrecht 3584 CM, the Netherlands.
authors.forename: Olga
authors.initials: O
authors.lastname: Amann
authors.forename: B P
authors.initials: BP
authors.lastname: Meij
authors.forename: Ineke
authors.initials: I
authors.lastname: Westerhof
authors.forename: Marja
authors.initials: M
authors.lastname: Kik
authors.forename: J T
authors.initials: JT
authors.lastname: Lumeij
authors.forename: Nico J
authors.initials: NJ
authors.lastname: Schoemaker
mesh_terms: D000818:Animals; D001715:Bird Diseases / Q000175:diagnosis / Q000473:pathology*; D001859:Bone Neoplasms / Q000473:pathology / Q000662:veterinary*; D005260:Female; D018212:Giant Cell Tumor of Bone / Q000473:pathology / Q000662:veterinary*; D010311:Parrots