RESUMEN
Osteosarcoma is the most common tumour that develops in the chest wall of dogs; an extensive excision is the treatment of choice. Various methods have been reported for reconstruction of chest wall defects following extensive excision. The objective of this report was to describe the complete resection of an extensive costal osteosarcoma with an extended resection of the ribs and part of the diaphragm in a dog. An 11-year-old neutered, male, miniature pinscher was presented with dyspnoea: An extensive mass was observed, stretching from the right chest wall to the abdominal wall. On computed tomography, the mass originated from the right 9th rib and exceeded the 6th rib on the cranial side and the 13th rib on the caudal side; it was compressing the lungs, diaphragm, liver, stomach and duodenum. When the patient's condition was medically stabilized, the tumour was removed from the right 9th rib. In consideration of the surgical margin, the 5th-13th ribs were excised, and the tumour was resected with the thoracoabdominal wall and part of the diaphragm. The missing thoracoabdominal wall and section of the diaphragm were reconstructed using two sheets of a polypropylene mesh. Postoperatively, flail chest was observed, although dyspnoea was not observed in the patient. Histopathological examination confirmed the diagnosis of osteosarcoma with a clean margin. Although 60.6 months have passed post-surgery, no metastasis has reoccurred. In this case, complete resection and reconstruction of the chest wall and diaphragm were achieved using a polypropylene mesh without fatal postoperative complications, despite extensive osteosarcoma resection.
