Lung adenocarcinoma with concurrent KRAS mutation and ALK rearrangement responding to crizotinib: Case report

Chromosomal translocation resulting in the fusion between the echinoderm microtubule-associated protein-like 4 (EML4) gene and the anaplastic lymphoma kinase (ALK) gene was recently identified as a novel genetic alteration in a subset of non-small cell lung cancer (NSCLC). EML4-ALK translocations are rare events associated with specific clinicopathological features, such as never or light smoking history, young age and adenocarcinoma with signet ring or acinar histology. Reports suggest ALK gene arrangements are mutually exclusive with EGFR and KRAS mutations. To the best of to our knowledge, this is the first case report of a patient with concurrent KRAS mutation and ALK translocation. This patient had an excellent response to crizotinib, suggesting that the ALK translocation was the oncogenic driver.