Recycling plastic: diagnosis and management of plastic bronchitis among adults

Abstract

Plastic bronchitis is a rare, underdiagnosed and potentially fatal condition. It is characterised by the formation and expectoration of branching gelatinous plugs that assume the shape of the airways. These airway plugs differ from the allergic mucin that characterises allergic bronchopulmonary aspergillosis and mucoid impaction of the bronchi. Plastic bronchitis is most often encountered in the paediatric population following corrective cardiac surgery, such as the Fontan procedure. It also occurs in adults. Plastic bronchitis in adults is rare, heterogeneous in its aetiology, and can lead to respiratory distress or even life-threatening airway obstruction. Plastic bronchitis in adulthood should not be overlooked, particularly in patients with chronic inflammatory lung diseases. This review presents current understanding of the presentation, aetiology, pathogenesis, pathology and management of plastic bronchitis in adults.

FIGURE 1

Pathological appearance of plastic bronchitis. Macroscopic tree-like appearance is a perfect cast of the bronchial tree.

FIGURE 2

Plastic bronchitis versus allergic bronchopulmonary aspergillosis/mucoid impaction of bronchi. a) Plastic bronchitis, low magnification. No lamellated appearance. Fibrin on the left; mucin on the right. b) Mucoid impaction of bronchi (allergic mucin) at low magnification. Lamellated appearance is apparent. The lighter areas (short arrow) contain mucin, while the darker areas (long arrow) contain debris with innumerable degenerating eosinophils. c) Plastic bronchitis, high magnification. Fibrin (arrow), mucin (arrowhead) and a few lymphocytes. No eosinophils. d) Mucoid impaction of bronchi (allergic mucin) at high magnification. A large number of degenerating eosinophils are present. e) Microscopic appearance of cast from case 1. The cast is a mix of fibrin (short arrow), mucin (long arrow) and lymphocytes (arrowhead). Haematoxylin-eosin stain, original magnification × 200.

FIGURE 3

a) and b) Lymphangiograms show abnormal thoracic lymphatic drainage patterns with a large duct (white arrow in b) that courses into the right hilar region and terminates in small peri-bronchial lymphatics.

FIGURE 4

Suggested algorithm for diagnosis and management of plastic bronchitis.

FIGURE 5

Macroscopic appearance of material removed from endotracheal tube. a) Cylindrical fragments of mucus-like material (arrow) seen in this formalin jar. b) The same material is shown at very low magnification (haematoxylin-eosin stain; 0.6× magnification).