Bilateral pneumothorax complicating cystic metastases of bronchial squamous cell carcinoma under erlotinib.

Cystic lung metastases are a rare presentation in non-small cell lung cancer and occurs mainly in squamous cell carcinoma. We present the case of a 57-year-old woman with a lung squamous cell carcinoma and cystic lung metastases, who developed bilateral metachronous pneumothorax while being administered erlotinib in third-line treatment. The apparition of a pneumothorax under chemotherapy is most often the result of tumor necrosis and formation of bronchopleural fistula. However, very few cases have been reported under targeted therapies, and to our knowledge this is the first case under erlotinib. This complication is potentially life-threatening, especially due to the possibility of pneumothorax bilateralization.