Tehran University of Medical Sciences Immunology and Genetics Journal 2645-4831 5 4 2022 12 22 159 163 Mohammad Reza Modaresi Pediatric respiratory and sleep medicine research center, children’s medical center, Tehran University of Medical sciences, Tehran, Iran Fateme Tarighat Monfared Pediatric respiratory and sleep medicine research center, children’s medical center, Tehran University of Medical sciences, Tehran, Iran 2023 11 21 2023 12 20 The present study describes a three-year-old girl who was referred to us due to stridor and snoring from one week of age and progressive worsening of sleep apnea two months before our visit. Gastroesophageal reflux disease was ruled out due to being unresponsiveness to treatment. Laryngomalacia was also ruled out because the symptoms and signs were aggravated by passing the time. The presence of a vascular ring was also overruled by echocardiography. Direct laryngoscopy and bronchoscopy were performed to investigate the vocal cord paralysis, glottic stenosis, airway foreign body, adenotonsillar hypertrophy, nasopharyngeal mass, and tracheal stenosis as the etiology. A tonsillar mass was found by them which was confirmed by CT scan. The surgical excision of the mass resulted in the complete resolution of the signs and symptoms. The pathologic studies of the resected mass found it to be follicular lymphoid hyperplasia (FLH), the most common benign lymphoid reaction of the nasopharynx area. https://igj.tums.ac.ir/index.php/igj/article/view/134 https://igj.tums.ac.ir/index.php/igj/article/download/134/113