Congenital lobar emphysema: the role of multislice computed tomography with virtual bronchoscopy in the differential diagnosis with bronchial foreign bodies

Abstract

We read with great interest the well-written manuscript by Jung et al. [1], which reported their experience with multislice computed tomography (MSCT) and virtual bronchoscopic (VB) reconstruction for the diagnosis of bronchial foreign bodies (BFBs) in pediatric patients. They discussed the importance of an early diagnosis, as any delay may cause serious complications. Most (90 %) of their cases presented with hyperinsuXation of the aVected lung, but only 40 % had witnesses to the aspiration event. Furthermore, about 90 % of BFBs are radiolucent and clinical examination Wndings are generally nonspeciWc. We would like to report our experience with a case of congenital lobar emphysema (CLE), a congenital disease that can simulate BFBs clinically and radiologically. The patient was diagnosed using MSCT and VB. A 5-month-old male was referred to our pediatric emergency ward due to respiratory diYculty. Examination conWrmed that the infant was experiencing mild respiratory diYculty; the respiration rate was 80 breaths/min, the heart rate was 130 beats/min, the facies were normal, weight was 6.0 kg, and length was 75 cm. Cyanosis, jaundice, and signs of heart failure were absent. An examination of the respiratory system revealed reduced movement, decreased vocal resonance, and diminished breath sound on auscultation of the left upper chest. Other systems appeared normal. A chest X-ray showed overdistension of the left-upper lobe, with a mediastinal shift to the right. A CT scan showed hyperlucent segments of the left-upper lobe (attenuated but intact pattern of organized vascularity) with no substantial midline herniation (Fig. 1a, b). Three-dimensional volume rendering (Fig. 1c) showed a high degree of stenosis in the apicoposterior segment. VB (Fig. 1d) conWrmed the highgrade stenosis and excluded other bronchial abnormalities. The postoperative pathological diagnosis conWrmed this initial diagnosis. Congenital lobar emphysema, also referred to as congenital pulmonary overinXation, most commonly aVects a single lobe of the lung, although multiple lobes or speciWc lobar segments may be involved. The disease is characterized by progressive lobar overexpansion, usually with compression of the remaining (ipsilateral) lung. The underlying cause can be a deWcient bronchial cartilage, endobronchial lesions, or extrinsic airway compression (e.g., by a large pulmonary artery or bronchogenic cyst), resulting in airway luminal narrowing and obstruction with air trapping. Although the alveoli expand, the alveolar walls remain intact; therefore, the term emphysema is technically inaccurate [2, 3]. In conclusion, CLE should be included in the diVerential diagnosis of BFBs, because both may present with pulmonary hyperinsuXation Wndings and nonspeciWc clinical features. Multislice CT with reconstructions of the B. Hochhegger · G. Zanetti · E. Marchiori (&) Universidade Federal do Rio de Janeiro, Rua Thomaz Cameron, 438. Valparaiso, Petropolis, Rio de Janeiro CEP 25685.120, Brazil e-mail: edmarchiori@gmail.com