Endotracheal and Endobronchial Metastases in Epidermal Growth Factor Receptor Exon 19 Deletion Lung Adenocarcinoma: A Case Successfully Managed with Bronchoscopic Therapy and Sequential Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors.

Endotracheal and endobronchial metastases from peripheral lung adenocarcinoma are rare, and optimal clinical management remains unclear. We herein report a 60-year-old woman with epidermal growth factor receptor (EGFR) exon 19 deletion-positive early-stage lung adenocarcinoma who underwent surgical resection followed by osimertinib treatment for recurrence. She later developed oligoprogressive disease with airway metastases. Bronchoscopic tumor removal was performed, and next-generation sequencing of the resected specimen revealed an acquired EGFR C797S mutation, along with exon 19 deletion. Gefitinib treatment was initiated, which led to a partial response. This case underscores the utility of repeated molecular profiling and local intervention in managing acquired resistance in EGFR-mutant non-small-cell lung cancer.