Cardiovascular manifestations of Erdheim-Chester disease

Erdheim-Chester disease (ECD) is a rare inflammatory disorder of unknown etiology, characterised by diffuse organ infiltration of CD68-positive, CD1a-negative, S100-low/negative foamy histiocytes. It is a non-Langerhans cell histiocytosis which invariably involves bones (96% of cases). Extraskeletal involvement is observed in about 50% of cases. Cardiovascular involvement affects more than 20% of patients and associates with poor prognosis, conferring a reduced response to treatment. Frequent findings are pericardial effusion (24% of patients), "coated aorta", a perivascular circumferential thickening of the aorta, and pericardial thickening. Other typical features include right atrial mass with pseudo-tumoural appearance and histiocytes' infiltration of right atrial walls, atrioventricular sulcus and interatrial septum. After the recent introduction of cardiac cine MRI in the clinical assessment of patients affected by ECD, a growing body of case reports and retrospective data showed that cardiovascular involvement is present more frequently than previously thought and that it is relatively often asymptomatic. Hence, clinicians should systematically screen ECD patients for occult cardiovascular involvement by means of highly sensitive imaging tools. Despite these recent novelties, comprehensive literature reviews focusing on ECD cardiovascular involvement and its imaging assessment in the last decade are lacking.