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.