A rare histiocytosis with severe cardiac involvement: Erdheim-Chester disease.

The term histiocytosis covers various disorders that lead to primary proliferation, infiltration and accumulation of cells of the mononuclear-phagocytic system within the affected tissues. Its pathophysiology is still unclear and the clinical course variable, which explains the lack of specific treatment and the need for a high level of suspicion to arrive at the diagnosis. The authors present the case of a patient with a complex cardiological clinical history, recently referred for surgical treatment of severe mitral insufficiency. Severe thickening of both atrial walls made it impossible to proceed with the intervention. After a complex etiological evaluation, a diagnosis of Erdheim-Chester disease was made. This is a rare, non-Langerhans cell histiocytosis and, to our knowledge, this represents the first case reported in Portugal. The authors also review the literature, particularly of the few cases with cardiac involvement.