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A5600 - 11 Month Old Infant with a Mediastinal Mass with Endobronchial Extension Presenting as Persistent Wheeze
Author Block: D. A. Krich1, S. Krishnan2, K. N. Harris3, N. Arlievsky4, A. J. Dozor5; 1Pediatric Pulmonology, New York Medical College, Valhalla, NY, United States, 2Pediatric Pulmonology, New York Med College, Valhalla, NY, United States, 3Pulmonology and Critical Care, New York Medical College, Scarsdale, NY, United States, 4Pediatric Infectious Disease, New York Medical College, Valhalla, NY, United States, 5Pediatric Pulmonology, New York Medical College, New York, NY, United States.
Introduction: Wheezing in infants is common, often unresponsive to bronchodilators, and usually improves over time. Therefore it can be challenging to determine when the benefits of an extensive diagnostic workup outweigh the risks. Unusual etiologies include anatomic anomalies, foreign body aspiration, endobronchial masses or external bronchial compression. Mediastinal masses in children are uncommon, and could have oncologic, infectious or embryologic origins. We report an 11 month-old with persistent wheeze unresponsive to therapy. Case Report: An 11 month previously health male infant was referred for evaluation of persistent wheeze for almost 2 months, unresponsive to inhaled bronchodilators and corticosteroids. There was no history suggestive of foreign body aspiration. There was a history of travel to Mexico, but no history of contact with tuberculosis. On physical examination, breath sounds seemed diminished on the left compared to the right, and there was an intermittent wheeze heard more loudly on the left. Previous chest x-rays were reported to be normal, but review suggested the left lung was more lucent than the right. CT and MRI suggested a middle mediastinal mass, 3 x 4 cm, with extension into the left main-stem bronchus. Blood counts, routine chemistry, ESR, CRP, quantitative immunoglobulins, fungal serology, and an interferon-gamma release assay for tuberculosis were all within normal limits. Mantoux was non-reactive. Blood cultures showed no growth. Flexible bronchoscopy confirmed an endobronchial mass, 1 cm in diameter, with > 90% occlusion of the left bronchus. With the assistance of Interventional Pulmonology, the mass was removed piece-meal with a biopsy forceps using a 4.0 mm OD flexible bronchoscope inserted through a laryngeal mask airway (LMA). Gram/Giemsa and AFB stains were non-conclusive. Histopathology reported necrotizing granuloma, etiology unknown. Subsequently, the mediastinal mass was removed by video-assisted thoracoscopic surgery. Smears/stains were negative, and histopathology confirmed necrotizing granulomas from which Mycobacterium avium complex was cultured. Subsequent history revealed the child often played in the soil/dirt on their family farm. Discussion: NTM presenting as a mediastinal mass with endobronchial occlusion has not been previously reported in infants less than 1 year of age. This case highlights the importance of close monitoring and evaluation of a young, otherwise healthy infant with persistent wheeze non-responsive to bronchodilators. Radiologic reports can be misleading. A detailed environmental history, even in very young children, can contribute to diagnosis. Interventional flexible bronchoscopic techniques can permit removal of endobronchial masses in young children without intubation and potential morbidities of rigid bronchoscopy.