Late Recurrence of Breast Cancer Nearly 30 Years After Surgery: Mediastinal and Hilar Lymph Node Metastases Diagnosed Using Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration.

Late recurrence of breast cancer occurring more than two decades after curative surgery is rare, but in the era of prolonged survival, clinicians may increasingly encounter such cases. Mediastinal or hilar recurrence may radiologically mimic primary lung cancer; however, histological confirmation using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) enables accurate diagnosis with minimal invasiveness. We report the cases of two patients who developed mediastinal and hilar lymph node metastases nearly 30 years after breast cancer surgery, for whom EBUS-TBNA played a crucial diagnostic role. A 68-year-old woman with a history of right mastectomy for stage I (T1aN0M0) breast cancer 30 years earlier presented with cough and hemoptysis. Chest computed tomography revealed multiple pulmonary nodules, right hilar lymphadenopathy, and sclerotic bone lesions. Fluorodeoxyglucose positron emission tomography/computed tomography showed intense uptake in the right hilar lymph nodes and bones, whereas pulmonary nodules demonstrated only mild uptake. EBUS-TBNA of station 12R revealed adenocarcinoma positive for estrogen and progesterone receptors and negative for human epidermal growth factor receptor 2, confirming metastatic breast carcinoma. The patient was treated with abemaciclib plus fulvestrant, achieving durable disease control for 2.5 years. A 70-year-old woman who had undergone left mastectomy 27 years earlier presented with a dry cough. EBUS-TBNA of stations 4R and 7 confirmed metastatic breast carcinoma. She received nab-paclitaxel followed by trastuzumab deruxtecan, achieving disease control for 20 months. These cases demonstrate that even very late recurrences nearly three decades after surgery can achieve prolonged survival when appropriately diagnosed and optimally treated. EBUS-TBNA is a valuable and minimally invasive diagnostic tool for confirming such a late recurrence.