Case 347: Tracheobronchial Smooth Muscle Atrophy and Separation

A 69-year-old woman presented to her primary care physician with new-onset dysphonia and increasing shortness of breath, without chest pain. She described her voice as "going in and out" intermittently and reported an occasional cough. She also reported globus sensation without dysphagia. Her medical history included long-standing allergic rhinitis, arthritis, anemia, and gastroesophageal reflux disease. She had a documented history of asthma and had been using the inhaled steroid fluticasone (100 μg/d) since at least 2013, along with an albuterol inhaler as needed for the past 3 years. The patient was a current smoker with a 40-pack-year smoking history, though she had made intermittent attempts to quit. She had undergone yearly lung cancer screening with low-dose CT since 2019. On examination, there was no increased work of breathing, and her lungs were clear to auscultation, with no crackles or wheezing. Echocardiogram was normal. Pulmonary function tests showed severe obstruction: a forced expiratory volume in 1 second (FEV₁) of 0.6 L (lower limit of normal, 0.98 L), with a z-score of -2.5 to -4, and a ratio of FEV₁ to forced vital capacity of 0.33 (lower limit of normal, 0.67). There was negligible improvement in FEV₁ or forced vital capacity (less than 10%) after bronchodilator administration. Air trapping was present, with a residual volume greater than 120% predicted, and diffusion capacity for carbon monoxide was reduced to 51%. Oxygenation (oxygen saturation) on room air at rest was normal. An otolaryngologic consultation was requested for the patient's new dysphonia, and flexible laryngoscopy was performed. Laryngoscopy revealed normal bilateral vocal cord movement but pachydermatous changes in the mucosa outlining the interarytenoid fold, which can be associated with nasopharyngeal reflux or chronic infection. As a part of the diagnostic workup for the increased shortness of breath, CT screening studies acquired in the patient in 2019, 2023, and 2024 were reviewed.