A case report of a lung cancer patient with two uncommon EGFR mutations and a review of the literature: two sides of the same coin

Lung cancer is the malignancy with the highest morbidity and mortality worldwide. Approximately 60% of non-small cell lung cancer (NSCLC) presents driver alterations most of which are targetable. Nowadays, limited clinical data are available regarding the efficacy of epithelial growth factor receptor (EGFR) tyrosine kinase inhibitors in patients with NSCLC harboring uncommon EGFR mutations, considering their heterogeneity. Herein, we report a rare case of EGFR-mutated lung adenocarcinoma which has developed into squamous cell carcinoma with uncommon EGFR (Ex18) compound mutations and phosphatidylinositol 3-kinase mutation receiving afatinib at the forefront.