Detection of meningeal metastasis in the cerebrospinal fluid in lung adenocarcinoma: A case report

For non-small-cell lung carcinoma patients with somatic epidermal growth factor receptor (EGFR) mutations, the first generation of EGFR tyrosine kinase inhibitors (TKIs) can be used, although acquired resistance may develop within about a year. Osimertinib is a third-generation EGFR-TKI, which is a preferred treatment for sensitizing mutations such as the T790M resistance mutation, and was approved for the treatment of advanced non-small-cell lung cancer with T790M drug resistance. We report a rare case of advanced lung adenocarcinoma with brain metastases that occurred in a patient who developed a headache after first-generation of EGFR-TKI treatment, although no abnormality was found by computed tomography or enhanced magnetic resonance imaging of the head. Cerebrospinal fluid (CSF) was assessed by CellSearch technology. Circulating tumor cells were found in the CSF samples, suggesting meningeal metastases. Further, EGFR L858R mutations were detected in the CSF by the amplification-refractory mutation system.(C) 2020 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).