Pulmonary Lymphangiomatosis – insights into an ultra-rare disease

Background: Pulmonary lymphangiomatosis (PL) is a very rare pulmonary disease with diffuse infiltration of the lung, pleura and/or mediastinum by abnormal lymphatics. Consented diagnostic or treatment approaches are not established. We therefore aimed to collect data on diagnostics and treatments in a cohort of patients with PL from a tertiary ILD center. Methods: Clinical, radiological and outcome data from PL patients were collected retrospectively. Results: 6 patients were diagnosed between 2007-2017. PL was diagnosed more commonly in female (83%), never smokers (67%) and younger patients (mean age 35 yrs). Main clinical symptoms comprised hem- and chyloptysis (50%) and dyspnea (33%). PFT was restrictive (mean VC 69%) with impaired DLCO (mean 68%). Radiological assessment showed mainly mediastinal involvement (100%), and pulmonary and/or pericardial effusions (50%), interstitial changes were rare (17%). Diagnosis was confirmed by surgical biopsy in all patients. 3 patients were treated with sirolimus, 1 combined with surgical intervention and radiotherapy and 2 received mediastinal surgical resections. Clinical and radiological improvement was demonstrated for all patients treated with sirolimus after a mean follow up of 20 months. 1 patient received lung transplant for disease progression. Survival rates were 83% after a mean follow up of 24 months. Conclusion: This case series illustrates the variability of the clinical presentation of PL. Treatment with Sirolimus may be a therapeutic option. However, further investigation is needed to understand the pathogenesis of lymphangiomatosis in order to establish therapeutic approaches.