Endobronchial Recurrence of Renal Cell Carcinoma 12 Years After Nephrectomy: A Rare Case Treated With Microwave Coagulation Therapy.

Endobronchial metastasis (EM) from renal cell carcinoma (RCC) is a rare manifestation of intrathoracic spread. RCC is known for its potential to recur long after nephrectomy, and EM may mimic primary lung cancer, complicating diagnosis and management. A 69-year-old male patient with a history of nephrectomy for RCC presented with progressive dyspnea. Imaging revealed a right hilar mass, and bronchoscopy identified a pedunculated polypoid lesion in the right main bronchus. Microwave coagulation therapy was performed to excise the lesion and achieve hemostasis. Histopathological analysis confirmed metastatic RCC. The patient was referred for systemic therapy following bronchoscopic intervention. This case highlights the diagnostic challenge of differentiating EM from primary lung cancer, especially in patients with a smoking history and elevated tumor markers. Bronchoscopic microwave coagulation therapy provided a safe and effective method for both diagnosis and airway management. Clinicians should remain vigilant for late recurrence of RCC, even more than a decade after nephrectomy. Bronchoscopic microwave coagulation therapy may serve as a minimally invasive option for the diagnosis and treatment of endobronchial lesions.