Abnormal Pulmonary Lymphatic Flow on Novel Lymphangiographic Imaging Supports a Common Etiology of Lymphatic Plastic Bronchitis and Nontraumatic Chylothorax

Background: This study evaluates whether dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) and thoracic duct lymphangiography (TDL) findings in adults with lymphatic plastic bronchitis (PB) and/or nontraumatic chylothorax (NTC) support a shared pathophysiology. Materials and Results: Retrospective review of clinical and imaging findings in patients who underwent DCMRL and TDL at a single institution from March 2017 to March 2019. Categorical variables were compared with Fisher's exact test. Twenty-eight patients (median age 61 +/- 21 years, 15 women) presenting with lymphatic PB (n = 13), NTC (n = 10), or both (n = 5) were included. Lymphatic imaging demonstrated pulmonary lymphatic perfusion (PLP) in all patients. A patent thoracic duct (TD) with retrograde flow was seen in 53.4% (7/13) of patients with PB, 60% (6/10) of patients with NTC, and 20% (1/5) of patients with both (p = 0.69). An occluded TD with retrograde flow was seen in 30.8% (4/13) of patients with PB, 30% (3/10) of patients with NTC, and 80% (4/5) of patients with both (p = 0.12). Similar patterns of PLP between DCMRL and TDL were seen in 96.2% (25/26) of patients. Conclusions: DCMRL and TDL demonstrated similar findings in patients with lymphatic PB and/or NTC, supporting a common etiology. This supports the hypothesis that the clinical presentation depends on the proximity of abnormal lymphatic vessels to the pleural cavity, resulting in chylothorax, or bronchial mucosa, resulting in PB.