Subglottic inflammatory myofibroblastic tumor: A rare case report in a pediatric patient

Abstract

Background: Inflammatory myofibroblastic tumour (IMT) of the pediatric laryngotracheal complex is exceedingly rare, with fewer than nine subglottic IMT cases reported in the literature up to 2025. We present an additional case and highlight the importance of early recognition. Case presentation: A previously healthy 10-year-old boy presented with a 3-week history of progressive dyspnea on exertion and nocturnal biphasic stridor, initially mislabelled as refractory asthma. Contrast-enhanced CT revealed a left-sided subglottic soft-tissue mass that reduced the airway lumen to 2.7 mm, while rigid bronchoscopy confirmed an 80% occlusion caused by a 10 mm submucosal lesion spanning the cricoid and first tracheal ring. After emergent tracheostomy at the referring institution, he underwent lesion resection and simultaneous decannulation. Histopathology demonstrated spindle-cell proliferation within a myxoid inflammatory stroma; immunohistochemistry was ALK-1–positive, confirming IMT. Post-operative bronchoscopy on day seven showed a widely patent airway. Five years later the child remains asymptomatic and oxygen-independent, with no radiological or endoscopic evidence of recurrence. Conclusion: This case reinforces that persistent pediatric stridor mandates prompt endoscopic evaluation and that complete surgical excision remains the gold-standard therapy for airway IMT. Given the tumour’s intermediate malignant potential and a reported 18–40% recurrence rate when margins are positive, meticulous long-term surveillance is indispensable, and ALK-directed therapy should be considered when resection is not feasible. Timely diagnosis and radical local therapy can avert prolonged tracheostomy and enrich the scant literature on pediatric subglottic IMT.

Introduction

Primary tumors of the trachea are rare pathologies, among these is the inflammatory myofibroblastic tumor which is an entity whose etiology has not been established.^1–3 However, the presence of an intermediate malignancy potential is considered due to its association with the alteration of the ALK gene which codes for the tyrosine kinase receptor. ⁴ Histologically it demonstrates a mixed inflammatory pattern accompanied by elongated fusiform well differentiated cells that in immunohistochemistry studies shows up to 50% positivity for ALK.^1,5 A prevalence of 0.04–0.07% is currently described among tracheal tumors, with a probability of recurrence between 18% and 40% depending on the resectability of the tumor.^3,5,6 The most common symptoms associated with the disease are dyspnea and stridor, as well as persistent wheezing and repeated pneumonia.^5,7 However, considering that it is a pathology with low incidence and varied presentation, its diagnosis is usually late. ⁸ By 2025, only a limited number of pediatric subglottic IMT cases have been reported in the literature, with fewer than ten well-documented cases,^9–12 most requiring tracheostomy before or after tumor resection, and only a few achieving immediate decannulation. These reports highlight persistent diagnostic delays and the absence of standardized surgical or postoperative protocols. No established protocol is found in case of incomplete resection. ⁷

Case description

A 10-year-old male patient presented with a clinical picture of progressive exertional dyspnea associated with laryngeal stridor, which was exacerbated at night. He was initially evaluated in the city of Pereira, where diagnostic imaging revealed a nodular-appearing lesion in the left subglottic region that obliterated the airway lumen, measuring 2.7 mm in diameter (Figure 1). Because of these findings at the referral center, a tracheostomy was performed, and he was referred for comprehensive management by a pediatric airway surgery team. At our institution, bronchoscopy was performed, showing a left-lateral tumor lesion of approximately 1 cm in a submucosal position at the subglottic level (at the cricoid and first tracheal ring), which occluded 80% of the airway. The team decided to perform an open surgical procedure (Figure 2), during which they completely resected the lesion and closed the tracheostomy without complications (Figure 3). Bronchoscopy in the first postoperative week demonstrated adequate airway patency and surgical wound healing (Figure 4). After surgical procedure, the histopathological report confirmed an inflammatory myofibroblastic tumor (Figure 5). After 5 years of follow-up, the patient has evolved satisfactorily, is asymptomatic, and does not require supplemental oxygen.

Figure 1.

Computed tomography of the thorax showing image of nodular appearance dependent on the left subglottic región. This is the only image available due to the limited resolution of the CT scanner used at the referring institution.

Figure 2.

Surgical visualization of the tumor.

Figure 3.

Surgical specimen.

Figure 4.

Bronchoscopy after surgery were the tumor was located.

Figure 5.

Histopathology of the tumor.

Discussion

Inflammatory myofibroblastic tumor (IMT) could be considered as a reaction of an insult, one of the theories is that it is a product of a response to trauma, viral or autoimmune disease. ¹³ The incidence of this type of tumor is less than 0.1%, being more common in pediatric age and young people, with a slight predominance in the female sex.^7,8 Its malignant potential has been demonstrated due to the presence of metastasis, recurrence and genetic abnormalities. A local recurrence rate of 37% and a metastatic recurrence rate of 11% have been described.^3,4,13,14 The intra-tracheal location of this pathology is infrequent, constituting 0.04 to 0.07% of all respiratory tract neoplasms in which 50% involve the bronchial tree and lungs.^1,5

The clinical presentation varies from being asymptomatic or presenting: cough, dyspnea, fever, stridor, respiratory symptoms, among others. Constitutional symptoms may also occur in advanced disease.^7,13,15 Our patient presented with stridor and exertional dyspnea.

The definitive diagnosis is obtained after the histopathological study of the surgical specimen, however, several previous imaging and paraclinical studies are required.^6,13 Radiological findings may be nonspecific, however, CT and MRI can provide tumor information on size, location and relationship to other structures, ultrasound may show images with irregular borders and different echogenicity.^1,3,15 This tumor often has increased vascularity on color doppler examinations, CT shows low, equal, or high attenuation compared with the surrounding tissue and MR images may show low signal intensity on T1 and T2. Bronchoscopy could help in the diagnosis of this type of pathology.^6,13,16 There is not a specific guide for diagnosis and treatment of Inflammatory myofibroblastic tumors.

Currently, the treatment of IMT consists of surgical resection with a recurrence rate of about 25% when complete resection is not achieved or the tumor behaves aggressively. ¹⁴ For surgical planning it is important to know the anatomy, the location of the tumor in relation to other organs, vascularization and whether there is transmural involvement of the trachea. ¹⁶ If complete surgical resection is not possible, other systemic therapy options may be required, particularly ALK-directed therapy in ALK-positive IMT.^4,9 Even though complete surgical resection confers prognostic value.^6,15 Long-term follow-up is mandatory to detect recurrence early. This case contributes new insight to the pediatric airway IMT literature by documenting immediate decannulation at the time of resection, 5 years of recurrence-free survival, and initial diagnostic delay due to asthma misdiagnosis. Given the scarcity of reported cases, collaborative multicenter efforts are needed to improve case characterization, refine surgical strategies, and define long-term prognosis^9–12

Conclusion: Inflammatory myofibroblastic tumor is a rare entity, especially in the pediatric airway, and its diagnosis is often delayed due to frequent misdiagnosis as more common conditions such as asthma, which increases the risk of life-threatening airway obstruction. Our case reinforces the need for early endoscopic evaluation of persistent stridor and confirms that complete surgical excision is the gold-standard treatment. Moreover, given the tumor’s intermediate malignant potential and recurrence risk, meticulous long-term surveillance is mandatory. Future collaborative studies across countries are needed to consolidate knowledge on pediatric airway IMT, improve diagnostic accuracy, standardize surgical approaches, and optimize outcomes.