Rhabdomyosarcoma in a Yellow-Headed Caracara (Milvago chimachima).

The article describes a case of rhabdomyosarcoma in a free-ranging yellow-headed caracara. Rhabdomyosarcoma started from the muscle area of proximal left humerus with metastases located in the left pectoral muscles, heart, lungs and proventriculus. Results of the histopathologic test showed neoplastic proliferation with spindle cells organized in irregular sheets or bundles with marked cellullar pleomorphism, moderate mitotic ratio as well as multinucleated giant cells.