We describe a 22-year-old man with a bone mass in the middle and lower third of the sternum with no signs of respiratory deterioration. After biopsy by incision established a diagnosis of hemangiosarcoma, appropriate resection and repair of the thoracic wall was scheduled. An adequate amount of tissue for analysis must be obtained to allow choice of a surgical technique that will assure the best prognosis in malignant tumors of the sternum and assignation of the most appropriate mechanical ventilation procedure.