Rib malignancies masquerading as benign mediastinal tumours.

Mediastinal tumours are commonly encountered in general thoracic surgery practice. Benign tumours like thymoma and teratoma often need direct surgical resection if resectable. Pre-operative biopsy is not recommended. We report 2 cases which were radiologically diagnosed as thymoma and teratoma turned out to be Ewing sarcoma and chondrosarcoma respectively after surgical excision. This has challenged the notion whether biopsy is really not needed. More elaborate studies are needed to find out tumour characteristics which would warrant a biopsy even if they are resectable. In our cases, pre-operative biopsy would have changed the line of management in both patients. This has led to a change in institutional protocol that now, we do biopsy for any mediastinal tumour more than 8 cm and abutting the chest wall.