Abstract Background Inflammatory myofibroblastic tumor (IMT) is a rare, intermediate-grade neoplasm that may present with airway obstruction in children. Its clinical and radiographic features can mimic more common conditions such as pneumonia, delaying diagnosis. The discovery of anaplastic lymphoma kinase (ALK) gene rearrangements has expanded therapeutic options beyond surgical resection. Case Presentation A 9-year-old female with a history of asthma and seasonal allergies presented with 2-3 months of progressive dyspnea on exertion and wheezing. Initial chest radiographs showed left hemithorax opacification, presumed to represent mucus plugging during an asthma exacerbation. Despite standard asthma therapy, her symptoms persisted. A contrast chest CT revealed a left main stem bronchial cut-off sign with complete left lung collapse. MRI confirmed a 4.0 × 2.7 × 2.6 cm hypo-enhancing mass extending through the left bronchial tree with complete lung atelectasis. Direct laryngoscopy and bronchoscopy (DLB) and flexible bronchoscopy identified a smooth, non-adherent, minimally vascular soft tissue mass completely obstructing the left mainstem bronchus. Biopsies were taken and histopathology revealed an ALK-positive inflammatory myofibroblastic tumor (IMT). Given the tumor’s proximity to major vessels, surgical resection was deemed infeasible. Targeted therapy with on Crizotinib, an ALK inhibitor, was initiated. Next steps include, reassessment with imaging, bronchoscopy for potential surgical resection after tumor shrinkage or endobronchial extraction. Discussion A rapidly growing lung mass often raises concerns for malignancy. However, in the absence of other systemic symptoms, rapidly growing benign tumors such as inflammatory myofibrobalstic tumor should remain in differential. This case underscores the importance of maintaining a broad differential for persistent unilateral lung opacification in pediatric patients. ALK-positive IMT, while histologically benign, can behave aggressively, leading to rapid airway compromise. Treatment usually involves surgical resection. Targeted therapy with ALK inhibitors offers a valuable non-surgical treatment option in unresectable cases. Conclusion Primary lung tumors are rare in children often requiring radiologic and pathologic findings for accurate diagnosis. Early recognition of endobronchial IMT is critical to prevent life-threatening airway obstruction. Targeted therapy has transformed the management of unresectable ALK-positive IMT in children, offering a path toward definitive treatment and improved outcomes. This abstract is funded by: None
Gannarapu et al. (Fri,) studied this question.