DISCUSSION: A review by Moser showed that 34 out of 328 cases of histologically proven and radiologically correlated Ewing sarcoma originated from the ribs. Thirty-two of these had an accompanying soft-tissue mass that was disproportionately large compared to the intraosseous involvement. This directly extends into the thoracic cavity, causing compression of the mediastinal structures. This patient had similar manifestations. Neoadjuvant therapy would have prevented significant morbidity, however, the mass effect caused cardiopulmonary compromise, prompting urgent surgical resection and a right pneumonectomy. Pneumonectomy is seldom performed in children. A bronchiectatic lung secondary to tuberculosis was the most common indication in the pre-antibiotic era. Malignancy is now the most common indication. Postpneumonectomy changes include elevation of the ipsilateral hemidiaphragm, hyperinflation of the remaining lung, shifting of the mediastinum towards the post-pneumonectomy space (PPS), and progressive resorption of air in the PPS and replacement with fluid, all of which were present in this patient. Fluid accumulates in the postpneumonectomy space and its careful management is important to maintain hemodynamic and respiratory stability. In this patient, fluid was intermittently drained from the postpneumonectomy space. There has only been 4 published cases of pneumonectomy done in children for pulmonary neoplasms and all survived the procedure. Postoperatively, the one-lung ventilation strategies of low tidal volume, high PEEP and a low FiO2 were employed. These aim to protect the lung from barotrauma and atelectasis. A restrictive ventilatory defect, which the patient demonstrated, was common in pneumonectomized patients. Postoperative complications of pneumonectomy are bronchopleural fistula, empyema, herniation of the remaining lung to the opposite side, scoliosis, and reduction in lung function (FVC and FEV1).