A Case of Intratracheal Ectopic Thyroid Presenting as Fixed Airway Obstruction

Document Type

Conference Proceeding

Publication Date

5-2026

Publication Title

American Journal of Respiratory and Critical Care Medicine

Abstract

Introduction: Asthma is frequently overdiagnosed, as up to half of patients labeled with severe asthma have an alternate diagnosis, including fixed upper airway obstruction. Intratracheal thyroid tissue (ITT) is a rare congenital anomaly that can mimic asthma due to nonspecific respiratory symptoms, often leading to delayed recognition and management. We present a case of ITT in a young woman initially treated for refractory asthma, highlighting the importance of considering upper airway lesions in the differential diagnosis of persistent respiratory symptoms.

Case Presentation: A 25-year-old woman with a history of “asthma”, vaping, and anemia was referred to the pulmonary clinic for progressive dyspnea unresponsive to bronchodilators. Her symptoms were exertional and worsened when lying supine. Physical examination revealed inspiratory stridor. Pulmonary function testing showed a moderate obstructive ventilatory defect (reduced FEV1/FVC with preserved FVC and normal DLCO) without bronchodilator response. The flow-volume loop demonstrated flattening of both inspiratory and expiratory limbs, consistent with fixed upper airway obstruction. Chest radiograph and CT thorax were unremarkable; however, CT neck revealed a 1.5 × 1.0 × 1.9 cm right-sided subglottic tracheal mass causing significant luminal narrowing. The patient was sent to the emergency department for airway monitoring. Rigid bronchoscopy identified a > 75% obstructing vascular lesion in the upper trachea, which was treated with argon plasma coagulation and snare resection, achieving approximately 95% debulking. Histopathologic evaluation revealed ectopic intratracheal thyroid tissue. Multidisciplinary tumor board review confirmed the benign nature of the lesion, and recommended surveillance bronchoscopy and repeat spirometry. The patient’s dyspnea resolved following resection.

Discussion: Ectopic thyroid tissue results from aberrant migration during embryologic development. It has been speculated that ITT arises from excessive development of Berry’s ligament with lateral tracheal dehiscence, allowing thyroid tissue to extend into the trachea. As with other benign intratracheal tumors, patients often present with nonspecific respiratory symptoms. Spirometry demonstrates fixed flattening of both limbs of the flow-volume loop. Imaging and bronchoscopy are essential for diagnosis and management, as endoscopic debulking is preferred as a minimally invasive approach. Open or segmental tracheal resection may be required in select cases, particularly when malignancy is suspected. Prognosis is generally favorable following complete resection, though recurrence and malignant transformation can rarely occur.This case underscores the importance of considering fixed upper airway obstruction in patients with “refractory asthma”, especially when stridor is present. ITT can cause severe obstruction and should be considered as a cause of unexplained central airway narrowing.

Volume

212

Issue

Suppl 1

First Page

S2346

Last Page

S2346

Comments

American Thoracic Society International Conference, May 15-20, 2026, Orlando, FL

DOI

10.1093/ajrccm/aamag162.3097

ISSN

1073-449X

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