Background: Lung cancer has highest mortality in both sexes. Current management of lung adenocarcinoma includes determining epidermal growth factor receptor (EGFR) mutational status as this is the target of erlotinib, a biologic therapy. Case report: A 62 yearold male with high smoking cancer risk presented chronic headache for a month, and magnetic resonance showed a brain tumor. Surgical specimen diagnosis was metastatic pulmonary adenocarcinoma by immunohistochemistry (TTF-1 (+)). An asymptomatic lesion in the right upper lobe of the lung was identified by tomography. Due to positivity to EGFR gene exon 21 mutation erlotinib was started; it was well tolerated by the patient. The patient died 31 months after diagnosis. Discussion: Treatment with erlotinib was initially indicated in the profile of an Asian and non-smoker woman patient. The overall survival rate with erlotinib in patient...