Long-Segment Malignant Tracheal Stenosis from Recurrent Medullary Thyroid Carcinoma Successfully Palliated with a Covered Self-Expanding Metallic Stent: A Case Report.

Background: Medullary thyroid carcinoma (MTC) may rarely cause malignant central airway obstruction (MCAO) through locoregional tracheal invasion, requiring urgent multidisciplinary management. In unresectable thyroid cancer-related MCAO, interventional bronchoscopy with airway stenting can provide rapid restoration of airway patency and symptomatic palliation. Case Presentation: A 58-year-old nonsmoking woman with a history of MTC treated with total thyroidectomy and adjuvant radiotherapy presented with progressive exertional dyspnea, productive cough, intermittent mild stridor, and recurrent respiratory infections. She was tachycardic and tachypneic but maintained oxygen saturation on room air. Physical examination revealed a firm, fixed mass in the thyroid bed region. Laboratory investigations showed mild anemia and thrombocytosis. Computed tomography demonstrated approximately 5 cm of tracheal involvement with critical luminal narrowing, consistent with malignant tracheal stenosis from suspected locoregional recurrence. Tracheal biopsy revealed high-grade carcinoma considered clinically compatible with recurrence, although immunohistochemistry and RET mutation testing were unavailable. The disease was deemed unresectable due to local invasion involving the trachea and carotid sheath. Because systemic targeted therapy was not locally available, urgent airway palliation was prioritized. A covered self-expanding metallic tracheobronchial stent was placed successfully across the stenotic segment, resulting in meaningful improvement in breathing and phonation. Conclusion: Covered metallic airway stenting is an effective palliative option for long-segment unresectable malignant tracheal stenosis caused by recurrent MTC, particularly when systemic targeted therapy is unavailable and rapid airway stabilization is required.