The case of a voluminous neoplasia originating at the manubrium sterni is described. Given the rapid growth of the mass and its dimensions, the mass was removed surgically together with the manubrium sterni and the sternal extremity of the clavicle and of the first two ribs. The defect in the anterior wall of the thorax was filled by a net of prolene partially covered with the mobilised pectoral muscles. Functional and aesthetic results were very good. Assisted respiration was not necessary in the immediate postoperative period and the net remained stable and firmly in place during respiration. One month after the operation, respiratory function tests were on a par with those done prior to the operation. The positioning of prolene nets for the reconstruction of the thoracic wall is an extremely effective technique which makes it possible to preserve satisfactory respiratory mechanics even after the removal of extensive portions of the thoracic wall.