Eyelash trichomegaly and durable complete response in a patient with metastatic lung adenocarcinoma receiving tyrosine kinase inhibitors: a case report

Background Erlotinib and gefitinib are oral first-generation tyrosine kinase inhibitors (TKIs) approved for the treatment of advanced non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor ( EGFR ) mutations. The most common adverse effects of these TKIs include rash and diarrhea. Eyelash trichomegaly is a rare adverse effect and not considered drug-limiting. This report presents a case of long-term complete response and TKI-induced eyelash trichomegaly in a patient with metastatic lung adenocarcinoma. Case presentation A 47-year-old Syrian woman with EGFR -positive recurrent metastatic lung adenocarcinoma was treated with gefitinib or erlotinib (as available) as monotherapy for 42 months and a complete response was achieved. After initiating erlotinib, the patient developed eyelash trichomegaly, which was managed conservatively with occasional trimming. When erlotinib treatment was discontinued, the elongated eyelashes regressed. Conclusions This case demonstrates the effectiveness of first-generation TKIs in treating metastatic EGFR -positive NSCLC, particularly in countries that cannot afford recent targeted therapies. In addition, it describes a rare adverse effect that was well tolerated and managed successfully.