Chronic expanding hematoma in sternum resected 5 years after median sternotomy.

Chronic expanding hematomas occur at various locations in the body; however, their occurrence in the sternum has not been reported yet. We report a patient with chronic expanding hematoma in the sternum 5 years after undergoing a median sternotomy for cardiac surgery. Although preoperative biopsy specimens did not lead to a definitive diagnosis, we could not rule out the possibility of a malignant tumor because of the expanding and infiltrative behavior of the hematoma. We performed a sternectomy and reconstructed the chest wall using artificial materials.