We are presenting a teenage girl with a recent history of virilism who presented with tension pneumothorax. Subsequent contrast-enhanced chest CT revealed multiple bilateral irregular thin-walled cysts of varying sizes with numerous solid noncalcified pulmonary nodules and pulmonary artery pseudoaneurysms. Lung biopsy revealed trophoblastic neoplasm with metastasis to both lungs. We discussed the differential diagnosis of diffuse cystic lung diseases. While diffuse cystic lung diseases in children are rarely due to malignancy, we emphasize that clinicians be aware of the possibility of metastatic lung diseases and their radiologic features when encountering diffuse cystic lung diseases.