Background
Plastic bronchitis (PB) is a rare disease characterized by the expectoration of rubbery, cohesive, and branched bronchial casts that obstruct the airway partially or totally. BP is associated with respiratory disorders such as bronchopulmonary infection, asthma, allergic bronchopulmonary aspergillosis (ABPA), and cystic fibrosis. However, it most commonly occurs in children with congenital heart disease, especially those with single ventricle physiology following the Fontan procedure. Elevation of central venous pressure after the procedure and secondary pulmonary lymphatic flow disorder (PLFD), leading to abnormal perfusion of the bronchial submucosa with lymph and formation of the airway cast 1-2. ‘Lymphatic PB’ is used to differentiate it from PB related to other causes3. However, PB caused by primary PLFD is rare and the clinical manifestation and severity vary among patients; thus, the diagnosis can be challenging, especially in the absence of chylothorax. In this paper, we report two cases of primary PLFD presenting primarily as PB, in order to contribute to further understanding of these disorders.