Chuck is an 8-year-old male castrated French Bulldog who was presented to the VSB Surgery Service with an approximately 3-week history of vomiting and newly recognized left cranial thoracic wall mass. The clients thought the mass may have been slowly growing over the previous year. The clients also reported that Chuck's appetite was decreased as well.

Thoracic radiographs were performed by the primary veterinarian which identified a large mass arising from the left cranial thoracic wall, possibly from the 3rd rib. Fine needle aspiration of the mass suggested either chondroma or chondrosarcoma. The mass was only about 3-4 cm wide externally, but that turned out to be just the “tip of the iceberg” so to speak.

A thoracic CT scan was performed to further evaluate the origin and extent of the mass. The mass was found arising from the left 3rd rib near the costochondral junction. The mass occupied a significant amount of the space in the cranial thorax, especially as it approached the thoracic inlet.

Representative transverse and dorsal plane CT images of the mass are presented for reference. The tumor is outlined with red triangles. The transition from normal 3rd rib to tumor is indicated by the red arrow. The heart is indicated by the yellow star. Since there was no obvious metastasis seen on the CT scan, chest wall resection and reconstruction were recommended.

The ventral half of the left 2nd through 4th ribs were removed. The resulting thoracic wall defect was closed using a polypropylene mesh which was then covered with adjacent muscle (latissimus dorsi and pectoral muscles provided most of the muscle coverage).

Chuck recovered well from surgery and was discharged from the hospital 2 days later. Histopathology confirmed well-differentiated chondrosarcoma with complete excision. Chuck was doing very well at his two-week follow-up exam with no discomfort or recurrence of clinical signs.

Chondrosarcoma is the second most common primary bone tumor in dogs and carries a significantly better prognosis than osteosarcoma. Metastatic rate for chondrosarcoma is relatively low. Median survival times for rib chondrosarcoma with curative intent surgical excision vary from 1080 to 3820 days, depending on the report. MST is shorter when chondrosarcoma is located within long bones (979 days) or the nasal passages (210-580 days) but still significantly better than osteosarcoma.