Cardiovascular Involvement in Erdheim-Chester Disease Presenting as Pericardial Tamponade: A Case Report and Multimodality Imaging Review.

Erdheim-Chester Disease (ECD) constitutes a rare and clinically heterogeneous non-Langerhans cell histiocytosis, characterized by the systemic infiltration of tissues by foamy, lipid-laden histiocytes. These cells typically exhibit an immunophenotypic profile positive for CD68 and negative for CD1a. The disease's multifaceted presentation, which can span from isolated bone lesions to fulminant multi-organ failure, frequently results in considerable diagnostic delay. In this case-based review, we describe the case of a 58-year-old who presented with a primary complaint of exertional dyspnoea and fatigue. The initial diagnostic evaluation revealed a hemodynamically significant circumferential pericardial effusion and imaging findings suggestive of aortitis. Clinical presentation of ECD depends on the organs and tissues involved, and may range from bone pain to neurological symptoms, endocrine dysfunction, and cardiac involvement. Cardiovascular involvement occurs in at least 40% of ECD patients, although it is frequently underdiagnosed. Cardiac ECD is heterogeneous and may mimic many alternative aetiologies. The infiltration of the right atrioventricular sulcus, right atrial walls, or interatrial septum is one of the most typical cardiac manifestations of ECD. Recognition of pseudo-tumour intra-atrial mass, pericardial involvement, as well as the circumferential encasement of the entire aorta, the so-called