A case of pneumothorax due to primary pulmonary osteosarcoma: When a common disease coincides with an unexpected cause

Abstract

Background. Most cases of osteosarcoma primarily occur in the bone of the trunk and the limbs. However, it is seldom found primarily in the lung. We herein experienced a case of primary pulmonary osteosarcoma. Case. A 59-year-old woman was admitted to our hospital due to a pneumothorax. She had been in a generally normal state until 3 days before the admission when dyspnea gradually developed. A chest X-ray showed a right pneumothorax and the patient had a cavernous lesion with a slightly thick wall in the right S1, which was connected with the pleural space and had a maximum size of 27 mm. We consulted with our respiratory surgery team, because air-leakage from the drainage tube had continued. A thoracoscopic excision of the cavity was subsequently performed. The histology and immunohistochemical findings of the lesion demonstrated an osteosarcoma. According to a PET/CT examination and a bone scintigram, since no accumulation was found in the other organs, the lesion was diagnosed as a primary pulmonary osteosarcoma. Conclusion. We experienced a patient with primary pulmonary osteosarcoma accompanied by a pneumothorax. A primary pulmonary osteosarcoma is a rare disease, and the case of a pneumothorax caused by an osteosarcoma is also extremely rarely.