A laceration of left internal mammary artery caused by an amateur golfer's swing.

We report the rare case of a patient presenting with a spontaneous laceration of left internal mammary artery (LIMA) after playing golf. The patient had no specific history except for cardiac surgery, and there were no results that caused bleeding on preoperative examination. A computed tomography (CT) scan of the chest demonstrated an anterior mediastinal hematoma and a left hemothorax with active extravasation close to LIMA. Through thoracotomy, hematoma evacuation and clipping for lacerated artery were performed. The patient was discharged in stable condition on the sixteenth postoperative day. This is the first reported case of a spontaneous laceration of internal mammary artery (IMA) after playing golf.