Abstract
Gefitinib is regarded as a relatively safe agent for the treatment of an advanced non-small cell lung cancer (NSCLC). Pulmonary toxicity such as interstitial lung disease associated with gefitinib is uncommon with an estimated all time incidence around 1% worldwide. Moreover, a case of gefitinib associated with pulmonary cystic changes has not been reported yet. In this report we present a case of progressive multiple air cystic changes in both lungs in a patient with NSCLC and intrapulmonary metastases who underwent a gefitinib therapy.