Pneumothorax Ex Vacuo Following Thoracentesis for Persistent Pleural Effusion

Pneumothorax ex vacuo (PEV) refers to a localized pneumothorax adjacent to a collapsed lung. Underlying causes of PEV include chronic atelectasis, endobronchial obstruction and visceral pleural restriction secondary to an inflammatory or malignant process. Recognition of PEV is crucial in directing appropriate treatment and refraining from unnecessary procedures, for example thoracosotomy tube placement. We present the case of 28 yo male who had a persistent pneumothorax following thoracentesis despite adequate thoracostomy tube drainage. Patient was subsequently diagnosed with a PEV secondary to bronchogenic adenocarcinoma. Treatment consisted of chemotherapy for underlying carcinoma and not thoracostomy tube.