[A case of chondrosarcoma originating from the left third rib].

Chondrosarcoma of rib origin is rare in Japan. A 51-year-old man came to our hospital with chest pain and coin lesion in the left superior part of the chest X-ray film. It was suspected to be the posterior mediastinal tumor based on CT and MRI. Operation was done to remove the tumor and the histological diagnosis was chondrosarcoma. The tumor measured 2.5 x 2.6 x 2.2 cm arising from the posterior portion of the left third rib. Combined resection of descending aortic adventitia was done. The patient is doing well without symptoms of recurrence 15 months after operation.