Primary tracheal small‐cell carcinoma detected 11 months after surgery for pulmonary large‐cell neuroendocrine carcinoma: A case report

Primary tracheal small‐cell carcinoma is rare, and is often treated using small‐cell lung cancer guidelines given that no standard treatment has been established for it. We report a patient in whom nodules appeared in the trachea and left main bronchus 11 months after surgery for pulmonary large‐cell neuroendocrine carcinoma; a biopsy revealed small‐cell carcinoma. Given the absence of malignant lesions elsewhere in the body, the lesions were diagnosed as primary tracheal small‐cell carcinoma. Respiratory failure progressed rapidly owing to airway stenosis caused by the growing lesion, and the patient required nasal high‐flow therapy. However, the lesions shrank a few days after commencing first‐line chemotherapy, and his respiratory failure resolved. Accelerated hyperfractionated radiotherapy was administered in conjunction with the third course of chemotherapy, and the patient ultimately achieved a complete response. Although the lesions were initially suspected of being postoperative recurrence of pulmonary large‐cell neuroendocrine carcinoma, the fact that the biopsy revealed them to be primary tracheal small‐cell carcinoma indicates that intra‐airway nodules that appear after lung cancer surgery may possibly be primary tracheal tumors.