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Platypnoea and Central Airway Obstruction as a Result of a Large Endotracheal Mass

1Division of Pulmonary, Critical Care, and Environmental Medicine, Department of Medicine, University of Missouri School of Medicine, Columbia
2Department of Medicine, University of Missouri School of Medicine, Columbia

We present a 55-year-old Caucasian male with an 80 packyear history of tobacco dependence and chronic bronchitis presented with a four-month history of worsening dyspnea and cough productive of thick yellow sputum. The patient revealed that his dyspnea and sputum production worsened when sitting upright and improved when laying supine (platypnea). He also noted increasing difficulty with sputum clearance that would only improve by placing himself in a Trendelenburg position. The patient experienced no improvement in symptoms following initiation of bronchodilator therapy and course of azithromycin. Physical examination demonstrated intermittent wheezing and a prolonged expiratory phase. The patient underwent a chest radiograph which demonstrated a mediastinal abnormality (Figure 1A). Pulmonary function tests were consistent with a fixed airway obstruction. This prompted further evaluation with a computed tomography (CT) scan of the chest which confirmed the presence of a distal tracheal lesion (Figure 1B-E). The patient ultimately underwent bronchoscopy which demonstrated an obstructive mass in the distal trachea. Histopathologic analysis of the samples obtained during bronchoscopy demonstrated extensively necrotic squamous cell carcinoma. The patient was referred to interventional pulmonology and underwent a rigid bronchoscopy with argon plasma coagulation (APC) and heat therapy for debridement of the endotracheal mass resulting in temporary improvement of his symptoms.
 

Central airway obstructions (CAO) represent a rare cause of chronic cough and recalcitrant dyspnea. CAO may be cause by malignant and non-malignant etiologies. Primary tracheal masses are a subset of malignant CAO with an estimated incidence of 600-700 cases per year [1]. Many patients will not experience symptoms from CAO until the trachea has been narrowed to less than 8 mm or the endoluminal diameter is less than 50% [2]. However, the degree of stenosis does not appear to correlate with severity of symptoms. In this particular case, the distal trachea was obstructed greater than 90% and flow volume loops demonstrated severe fixed obstruction (Figure 2). The patient was not hypoxic but did report increasing difficulty performing activities of daily living. He underwent APC with mechanical tumour resection, resulting in reduction in the degree of stenosis to less than 20% along with a marked improvement in symptoms. APC has been shown to be superior to cryotherapy as an intervention for malignant airway obstruction and in conjunction with mechanical tumour resection is the cornerstone of therapy for CAO [3].
 

This case represents the need for a thorough history and for critical thinking when clinical response to standard therapy for dyspnea and cough do not produce the intended response. The mainstay for diagnosis of CAO revolves around the use of chest CT scan and bronchoscopy. Pulmonary function tests, though they do not change management, can offer important information to help gauge the response to therapeutic interventions. CAO represents an entity that although rare has a heavy impact on patients. Those individuals who are found to have CAO should be referred to large tertiary care centers who have access to interventional pulmonary and have the ability to manage difficult airways.

1. Ernst A, Feller-Kopman D, Becker HD, et al. Central airway obstruction. Am J Respir Crit Care Med. 2004;169:1278-1297.
2. Mudambi L, Miller R, Eapen GA. Malignant central airway obstruction. J Thorac Dis. 2017;9:S1087-S110.
3. Kizilgoz D, Aktas Z, Yilmaz A, et al. Comparison of two new techniques for the management of malignant central airway obstruction: Argon plasma coagulation with mechanical tumor resection versus cryorecanalization. Surg Endosc. 2018;32:1879-1884.