Erdheim-Chester disease: Patterns and pulmonary involvement

Abstract

Background: Erdheim-Chester disease (ECD) is a rare, non-Langerhans cell histiocytosis with multisystem involvement. Its protean manifestations and mimicry of several neoplastic and inflammatory conditions often lead to late diagnosis, when severe functional impairment or life-threatening disease has occurred. Prognosis remains poor, although published data on the use of interferon α (IFN-α) and BRAF inhibitors have expanded therapeutic options. Objective: To compare patterns of disease presentation and factors influencing the outcomes of patients with ECD, with emphasis on cardiopulmonary organ involvement. Methods: We retrospectively examined clinical, radiologic and pathologic records in 8 patients diagnosed with ECD in 3 tertiary centres from Jan 2006 to Dec 2015. Results: Median age at diagnosis was 56 years old. Progressive dyspnea was the most common symptom (88%). Median time from symptom onset to diagnosis was 13 months. Neurological, skeletal, cardiopulmonary, vascular and renal involvement were most common. All patients had radiographic lung involvement, with varying degrees of functional limitation: interlobular septae or fissural (75%), pleural (63%), nodular (63%), ground glass (50%), fibrosis or honeycombing (25%), consolidation (25%), cysts (13%). Most patients had cardiac (atrial, pericardial) and vascular (peri-aortic) involvement. Lung biopsy was diagnostic in only one patient. Three patients tested positive for the BRAFV600E mutation. Four of 5 patients who received pegylated IFN-α survived at 3 years. Conclusions: Cardiopulmonary involvement in ECD may be more common than previously described, although with varying degrees of functional limitation. Pegylated IFN-α is efficacious in most instances.