Bronchial Casts Eluding a Diagnosis of Pulmonary Lymphangiectasia

Abstract

INTRODUCTION: Plastic bronchitis is characterized by inspissated casts in the bronchial tree. We describe a patient with plastic bronchitis and underlying pulmonary and intestinal lymphangiectasia. CASE PRESENTATION: A 14-year-old male with history of mild persistent asthma presented with coughing up stringy cheese-like-material (figure 1) for the past few months. He had three episodes of pneumonia in the previous year with progressive orthopnea and decreased exercise tolerance. He had decreased breath sounds in right lung base and expiratory rhonchi. Pulmonary function tests showed hyperinflation with decreased flow rates. Chest X ray showed increased opacities of right lung base. High resolution CT scan showed intra-bronchial casts, ground glass opacification with <> (figure2) in right lung base. Sweat chloride test, echocardiogram, surfactant protein levels and rheumatologic work up were normal. Bronchoscopy revealed thick mucus strands with milky lavage fluid. Broncho-alveolar-lavage cultures and Periodic Acid Schiff stain were negative. Presence of lymphopenia, hypo-albuminemia, low immunoglobulin levels, and elevated stool alpha-1-antitrypsin suggested protein-losing-enteropathy. He required multiple emergent bronchoscopies to relieve his casts. He subsequently developed right-sided chylothorax. Lung biopsy showed dilated, muscularized lymphatics. Small bowel biopsy showed intestinal lymphangiectasia. Pedal lympho-scintigraphy suggested obstruction of lymphatic pathway. He was treated with airways clearance, chest vest, inhaled steroids, inhaled mucomyst, prophylactic antibiotics, azithromycin and monthly immunoglobulins. He was admitted for prolonged chest tube drainage, bowel rest and Octeotride infusion. However, chylothorax persisted and surgical ligation of thoracic duct with talc pleurodesis was performed. He was transitioned to a low fat diet. He has been doing well for the past year with occasional exacerbations but no further hospitalizations. DISCUSSION: Primary pulmonary lymphangiectasia is a developmental anomaly of lymphatic vessels of unknown etiology that usually presents in the neonatal period but can present later in life(1). Bronchial casts are typically inflammatory (asthma, cystic fibrosis) or non-inflammatory (structural heart disease, sickle cell disease). Reports of chylous casts secondary to lymphatic disorder are extremely rare(2). CONCLUSIONS: A high index of suspicion is warranted in the diagnosis of lymphatic disorders.