Plastic Bronchitis

Abstract

CASE REPORT A 27-month-old white girl came to our institution with a 48-hour history of cough, high temperature, and dyspnea. Physical examination showed a pulse of 100 beats/min and a respiration rate of 30 breaths/min. Her left lower lung zone revealed dullness to percussion and decreased breath sound. Chest roentgenogram showed mediastinal displacement to the left and increased left lung attenuation. Laboratory test results indicated a white blood cell count of 15,000 cells/μL; erythrocyte sedimentation rate, 31 mm/hr. She was then administered antibiotic treatment. On hospital day 2, the child presented progressive respiratory distress requiring admission to the intensive-care unit. Physical examination revealed absent breath sounds on the left hemithorax. Chest roentgenogram showed left lung atelectasis (Fig. 1). At this time, the parents reported a choking episode while the child was eating nougat pieces 2 days previously; thus, rigid bronchoscopy under general anesthesia for suspected foreign body aspiration was performed.FIGURE 1: Chest roentgenogram showing left lung atelectasis.The left bronchial system was completely plugged from the main carina by pale tan rubbery casts taking the form of the bronchial tree anatomy; this condition was described as plastic bronchitis (Fig. 2). This material was extremely hard to remove bronchoscopically because it was too soft to grab with forceps but too thick to suction. Removal of this material required continuous suctioning. The left bronchial mucosa was edematous and bled easily. There was no complication during or after bronchoscopy.FIGURE 2: Pale tan casts resembling left bronchial tree anatomy.Chest radiographic findings showed improvement on the day after the procedure. The duration of hospitalization was 4 days. The patient made a full recovery. Pathologic examination of the casts revealed fibrinous exudate admixed with mucin and a few exfoliated epithelial cells; no inflammatory cells, microorganisms, eosinophils, fungi, malignant cells, or crystals were seen. Cultures for bacteria were negative. DISCUSSION Plastic bronchitis is a rare disorder in which large, pale tan bronchial casts of a rubber-like consistency develop in the tracheobronchial tree and cause airway obstruction.1 It has also been called fibrinous bronchitis, pseudomembranous bronchitis, Hoffmann's bronchitis, and cast bronchitis.1-3 Plastic bronchitis is typically seen in association with congenital heart diseases4 and several primary pulmonary disorders, including asthma,5,6 pneumonia,1 lymphagiomatosis,8-10 allergic bronchopulmonary aspergillosis,11 cystic fibrosis,12 bronchiectasis,7-13 acute chest syndrome associated with sickle cell disease,14 and idiopathic states.1,2,5,10,15,16 The casts are of variable sizes and take the shape of the bronchi in which they formed. The pathophysiology is unknown. Seear et al5 proposed that bronchial casts could be divided into 2 distinct clinicopathologic groups. Type I casts are inflammatory, consisting mainly of fibrin with cellular infiltrates and occur in inflammatory diseases of the lung. Type II, or acellular casts, consist mainly of mucin with a few cells and usually occur either in patients with palliated congenital heart disease or in those with primitive plastic bronchitis. Langeupin et al4 suggested that the pathophysiology in patients with congenital heart disease involves the development of endobronchial lymph leakage. The presence of large, obstructive plugs filling the airways of lobes or the entire lungs can result in a variety of clinical signs and symptoms, and could ultimately lead to respiratory failure and death. A high degree of suspicion is necessary to make the diagnosis of this entity that is probably underestimated. Plastic bronchitis can mimic foreign body aspiration or status asthmaticus. Any child with severe respiratory distress refractory to aggressive conventional medical therapy and with a history or radiograph suggestive of plastic bronchitis should be considered a candidate for bronchoscopy. Conventional treatment of cast bronchitis has focused on the clearance of obstructing material from the airways by bronchoscopy combined with therapy for any underlying cardiopulmonary disease. Because plastic bronchitis is a rare disorder associated with variable disease states, specific therapeutic options are based primarily on anecdotal experience.1,4,5,8,16-22