Inspiratory stridor is an important clinical finding that requires immediate and adequate evaluation of the underlying etiology in children. Some of the commonly encountered causes are acute laryngotracheobronchitis, laryngomalacia, and foreign body aspiration. Other rare causes should be considered if basic work-up does not reveal any of these common etiologies.

A 3-month-old girl was brought to our pediatric emergency services with history of cough and cold, noisy breathing and chest indrawing for last five days. She had inspiratory stridor with subcostal and suprasternal retractions on examination, with bilateral equal air entry on auscultation. Chest X-ray and X-ray neck were apparently normal. At admission, child was treated with steroids and adrenaline nebulization considering a diagonosis of acute laryngotracheobronchitis. As there was no symptomatic improvement, direct laryngoscopy was performed that did not show evidence of any abnormality. Contrast enhanced computed tomography (CECT) neck showed a lateral pharyngeal mass (Fig. 1A). Transoral surgical procedure was performed under general anesthesia, and a 1.5 x 1.5 cm cyst in the left lateral pharyngeal wall closely abutting the left arytenoid was seen (Fig. 1B). Thick whitish fluid was aspirated and cyst was marsupialized. No pus cells were seen on microscopic examination. Fluid culture grew normal respiratory flora. Biopsy of the cyst wall showed stratified squamous epithelium and a final diagnosis of left pharyngeal wall submucosal retention cyst was made. Child was discharged four days after surgery. On follow up, child had no stridor or respiratory distress.

Fig. 1 (A) CECT showing lateral pharyngeal wall cyst; and (B) Intraoperative left pharyngeal wall cyst.

Stridor may be the first sign of a life-threatening disorder. Acute onset stridor can result from obstruction to the airway anywhere from nose to thoracic trachea and major bronchi [1]. Common causes of obstruction at the level of pharynx include retropharyngeal and parapharyngeal abscesses. Some of the rare causes include dermoid cyst, thornwald cyst, duplication cyst, pharyngeal teratoma and pharyngeal choristoma [2,3]. Pharyngeal wall sub mucosal retention cyst is an uncommon cause of stridor in children. A timely imaging procedure like CECT helps in correct diagnosis and appropriate management.

1. Tunkel DE, Zalzal GH. Stridor in infants and children: ambulatory evaluation and operative diagnosis.　Clin Pediatr. 1992;31:48-55.

2. Posod A, Griesmaier E, Brunner A, Pototschnig C, Trawöger R, Kiechl-Kohlendorfer U. An unusual cause of inspiratory stridor in the newborn: congenital pharyngeal teratoma – a case report. BMC Pediatr. 2016;16:1.