Spontaneous pneumothorax in metastatic osteosarcoma: a case series

Abstract
Background
Malignancy-associated secondary spontaneous pneumothorax (MSSP) has an incidence of 1% with a risk for recurrence of 9.4% reported in association with sarcomas, histiocytoma, malignant thymoma, and cancers of the breast and thyroid.

Case presentation
We report a series of four patients who presented to us with MSSP associated with pulmonary metastasis of osteosarcoma, all four being young males with metastasis to the lungs. All four patients were non-smokers and had no family history of malignancy. Less than 2% of all spontaneous pneumothoraxes present with bilateral pneumothorax, and our series reports the same in three patients. The occurrence of pneumothorax in two of the patients was in the week following chemotherapy. As there was evidence of pulmonary metastasis in these patients along with the clinical presentation of pneumothorax following chemotherapy, tumor necrosis was considered the likely etiology of spontaneous pneumothorax in these patients. All four patients required intercostal chest drain insertion, and the ICD tubes had to be retained for a prolonged duration due to either persistent air leak or secondary infection. ICD tube insertion further compromised the poor mobility of patients with lower limb lesions due to increased pain and was detrimental to the emotional morale of the patient and caregivers. The 2-year survival in such patients with pneumothorax is less than 10%.

Conclusions
Our series highlights the need for respiratory evaluation and follow-up both clinically and radiologically in cases of osteosarcoma, especially in the immediate post-chemotherapy period.