Tracheal Mucoepidermoid Carcinoma Complicated with Papillary Thyroid Carcinoma

Primary tracheal carcinoma is a rare malignant tumor; among all malignant tumors, it is reported to occur account for 0.04% of malignancies in Japan and 0.1% in Europe and the United States, with squamous cell carcinoma, accounting for 45%, and adenoid cystic carcinoma, accounting for 41%. We report the case of a 79-year-old woman with papillary thyroid carcinoma, cT4aN0M0 (right recurrent), with laryngeal nerve and tracheal wall invasion, The patient underwent total thyroidectomy, right recurrent laryngeal nerve resection, and tracheal fenestration. On the 16th postoperative day, when attempting to remove the cannula, dyspnea developed, and the bilateral vocal cords were observed. The patient was diagnosed with paralysis. This did not improve despite follow-up. The patient was referred to our hospital for glottis surgery. Preoperative computed tomography (CT) images showed a mass protruding from the left wall of the trachea into the lumen, and pretracheal lymphadenopathy, suggesting intratracheal recurrence of papillary thyroid carcinoma and cervical lymph node metastasis. Therefore, glottis surgery was temporarily suspended and tumor resection (tumor resection including combined resection of the trachea and reconstruction of the tracheal wall using a DP flap) was planned and the operation was performed. A pathological examination revealed papillary carcinoma lymph node metastasis in the pretracheal lymph nodes, but the tumor tissue in the trachea was found to be low-grade mucoepidermoid. carcinoma, not papillary carcinoma. In the present case an intratracheal lesion after surgery for papillary thyroid carcinoma was identified as primary mucoepidermoid carcinoma of the trachea.