(A906) ALK+ Histiocytic Subglottic Lesion: An Unusual Presentation of Biphasic Stridor

Introduction: ALK-histiocytic lesions are rare neoplastic disorders characterized by abnormal histiocytes with anaplastic lymphoma kinase (ALK) gene rearrangements, typically presenting with systemic or localized tissue infiltration in young children. Presentations in the airway are exceedingly rare, and there are no prior reports of endoscopic management for children with ALK-histiocytic lesions in the subglottis leading to airway obstruction.

Methods: We report a novel case study of a 3-year-old boy with progressively worsening biphasic stridor, found to have an isolated ALK+ histiocytic lesion in the subglottis. The patient was first seen in September 2024 in the setting of an urgent airway evaluation. This case represents the first reported instance of an isolated ALK+ histiocytic subglottic lesion managed with endoscopic debulking.

Results: The patient initially presented with three months of biphasic stridor and cough with modest improvement on asthma therapy. In-office flexible laryngoscopy revealed an asymmetric, narrowed subglottis, and urgent direct bronchoscopy was recommended. This revealed a firm, round, submucosal mass originating from the right cricoid and obstructing approximately 80% of the lumen. Biopsy yielded no significant bleeding, lowering the concern for a vascular lesion. Histopathology confirmed an ALK+ histiocytic lesion, with immunohistochemistry negative for desmin, myogenin, and S100. PET/CT showed no other disease sites. Following confirmation of the pathology, the patient was managed with endoscopic resection and monitoring via serial endoscopy.

Conclusions: This is the first reported case of isolated ALK+ histiocytic lesions in the airway that has been managed with endoscopic management. Given its unusual location and presentation, it is incumbent upon pediatric otolaryngologist to be aware of management options for the patient.