Abstract Background Osteosarcoma is a malignant tumor of the bone. The giant cell-rich osteosarcoma (GCRO) is a rare histological variant of the conventional osteosarcoma, accounting for 3% of all osteosarcomas. It has a variable clinical presentation, ranging from asymptomatic to multiple pathological fractures, mainly involving long bones, and less frequently the axial skeleton and soft tissues. Case presentation We present the case of a 25-year-old Hispanic woman, previously healthy, with a 1-month history of dyspnea on exertion, intermittent dry cough, hyporexia, and intermittent unquantified fever. She presented to the emergency department with a sudden increase in dyspnea during which she quickly entered ventilatory failure and cardiorespiratory arrest with pulseless electrical activity. Resuscitation maneuvers and orotracheal intubation were initiated, but effective ventilation was not achieved despite intubation and she was transferred to the intensive care unit of our institution. The chest radiograph showed a mediastinal mass that occluded and displaced the airway. The chest tomography showed a large mediastinal mass that involved the pleura and vertebral bodies. A thoracoscopic biopsy was performed that documented a conventional giant cell-rich osteosarcoma. The patient was considered to be inoperable due to the size and extent of the tumor and subsequently died. Conclusions The giant cell-rich osteosarcoma is a very rare histological variant of conventional osteosarcoma. Few cases of this type of osteosarcoma originating from the spine have been reported in the literature, and to our knowledge none of the reported cases included invasion to the chest cavity with airway compression and fatal acute respiratory failure that was present our case. Radiological and histological features of the GCRO must be taken into account to make a prompt diagnosis.