A case of primary lung cancer with EGFR mutation which needed to be distinguished from lung metastasis of breast cancer

Abstract

Background : We report a case of primary lung cancer having to be distinguished from breast cancer lung metastasis focusing on liquid-based bronchial brushing cytology, immunocytochemistry, and epidermal growth factor receptor (EGFR) mutation.
Case : A 60-year-old woman with a breast cancer history seen for back pain was found in computed tomography and bone imaging to have bone metastasis and a pulmonary nodule. Liquid-based bronchial brushing cytology results yielded a diagnosis of primary lung cancer. Immunocytochemistry and peptide nucleic acid-locked nucleic acid polymerase chain reaction clamp assay results showed an EGFR mutation exon 21 L858R.
Conclusions : EGFR mutation may also be detected by immunocytochemistry. Immunocytochemistry and molecular techniques using cytological material in personalized medicine are necessary.