Abstract Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal neoplasm of intermediate malignant potential, with a predilection for children and adolescents. Although the lung parenchyma is a frequent site, true endobronchial involvement is uncommon, which can delay diagnosis and complicate management. Awareness of this entity is critical in children presenting with persistent or recurrent pneumonia or endobronchial lesions. A 5-year-old previously healthy male presented with a two-month history of recurrent upper respiratory symptoms and fever. Repeated chest radiographs demonstrated right upper lobe (RUL) pneumonia, and subsequent chest computed tomography (CT) was concerning for an endobronchial obstructive lesion, post-obstructive atelectasis, and bronchiectasis. Initial bronchoscopy identified an obstructive endobronchial mass at the entrance of the RUL bronchus (Figure 1). Biopsies were obtained but yielded insufficient tissue for diagnosis. A second flexible bronchoscopy by a pulmonologist and a microlaryngoscopy-bronchoscopy by an Ear, Nose, and Throat (ENT) surgeon were performed, during which the mass was biopsied and debulked. Histopathology confirmed an inflammatory myofibroblastic tumor with an ALK1-PPFIBP1 fusion. The patient was initiated on crizotinib by Oncology, an ALK inhibitor, with subsequent improvement in airway patency. Follow-up chest CT and bronchoscopy demonstrated persistent RUL atelectasis and bronchiectasis, but without residual obstruction, confirmed with repeat bronchoscopy. Multidisciplinary review among pulmonology, ENT, oncology, and thoracic surgery teams recommended continuation of crizotinib therapy and consideration of elective surgical resection of the RUL if evidence of tumor recurrence or recurrent pneumonia. After 7 months of treatment, the family elected to proceed with RUL lobectomy due to the burden of airway clearance and frequent bronchiectasis exacerbations. This case highlights the diagnostic and therapeutic complexity of endobronchial inflammatory myofibroblastic tumors in children. IMT accounts for up to 20% of primary benign pulmonary neoplasms in children, though endobronchial presentation is rare. Endobronchial IMTs may mimic infectious or inflammatory processes, including granulation tissue from a retained foreign body, which can delay recognition, but should remain in the differential diagnosis of endobronchial lesions. Debulking via microlaryngoscopy-bronchoscopy and flexible bronchoscopy can provide both diagnostic and interventional benefits, while integrating molecular testing and multidisciplinary care is essential to optimize outcomes. Given its potential for recurrence or progression, early identification and coordinated management are vital for favorable long-term outcomes. Figure 1. Initial findings demonstrated RUL atelectasis secondary to an obstructing endobronchial mass. (A) Chest X-ray showing RUL atelectasis. (B) Chest CT revealing an obstructing endobronchial lesion in the RUL bronchus. (C) Bronchoscopic view showing the intraluminal mass. This abstract is funded by: None
Patel et al. (Fri,) studied this question.