Successful treatment of diffuse pulmonary lymphangiomatosis with sirolimus

Diffuse pulmonary lymphangiomatosis (DPL) is a rare disease characterized by uncontrolled proliferation of anastomosing lymphatic channels in the lungs, pleura and mediastinum. Several palliative treatment options have been suggested for this condition, such as surgical interventions, radiotherapy and systemic medications. However, the existing treatment modalities yield inconsistent results, and their use is often limited by toxic side effects. The aim of this case report is to demonstrate the diagnostic challenges of a rare disease and improvement in the condition of a DPL patient treated with sirolimus. A 27-year-old man presented to the pulmonologist with exertional dyspnea, chronic cough and intermittent hemoptysis. Upon medical investigation, a chest computed tomography (CT) scan revealed soft tissue masses infiltrating the mediastinum and bilateral interlobular septal thickening. A surgical biopsy was performed, and pathological tissue analysis showed findings consistent with the diagnosis of DPL. Treatment with sirolimus was initiated, maintaining trough concentrations between 10 and 15 ng/ml. At 21 months of treatment, the patient reported reduced symptoms of cough and dyspnea. A CT scan showed decreased interstitial thickening and reduced infiltrations in the mediastinum. Moreover, pulmonary function tests revealed a significant increase in FEV1 and FVC. The authors believe this is the first article reporting pulmonary function improvement in an adult DPL patient treated with sirolimus. Therefore, sirolimus therapy should be considered for DPL patients as it may be effective in improving their condition and preventing disease progression.