Inflammatory myofibroblastic tumor (IMT) is an uncommon mesenchymal neoplasm rarely encountered in the pediatric larynx, with the subglottis representing an atypical subsite. This report details a diagnostically instructive case of a 10-year-old girl presenting with 18 months of progressive dyspnea and exertional stridor, notably without hoarseness. Fibroendoscopic laryngoscopy identified a well-circumscribed right subglottic mass, confirmed on computed tomography scan to cause partial airway narrowing. The lesion's firm intraoperative consistency contrasted with common benign mimics. Histopathology revealed spindle cell proliferation with mixed inflammation (histiocytes, giant cells), while immunohistochemistry demonstrated focal anaplastic lymphoma kinase (ALK) and smooth muscle actin (SMA) positivity, CD68+ histiocytes, and CD1A negativity-collectively confirming IMT and excluding Langerhans cell histiocytosis. Complete endoscopic excision was achieved. This case underscores critical learning points: (1) IMT must be considered in children with progressive stridor/dyspnea, even lacking hoarseness, particularly with subglottic localization, and firm consistency; (2) Subglottic IMTs primarily manifest airway obstruction rather than voice changes typical of glottic lesions; (3) Focal ALK expression, present here, supports clonality but does not preclude a favorable outcome with complete resection; and (4) Immunohistochemistry (ALK/SMA/CD68/CD1A) is indispensable for accurate diagnosis and avoiding misdirected therapy. Despite excellent early postoperative results consistent with the generally favorable prognosis of pediatric IMT, vigilance for recurrence-highest within the first 2 years-remains essential. This report reinforces complete conservative resection as the cornerstone of management for localized disease, reserving adjuvant therapies for complex or recurrent scenarios. Multidisciplinary collaboration optimizes outcomes while preserving laryngeal integrity in children.
Keywords: airway obstruction; inflammatory myofibroblastic tumor; pediatric laryngeal tumor; stridor; subglottic tumor.