Cardiac and pleuropulmonary involvement in Erdheim-Chester disease without bone lesions: A case report.

Erdheim-Chester disease is a rare multisystemic non-Langerhans histiocytosis characterized by histiocytes that stain positive for CD68 and negative for CD1a. Skeletal involvement is reported to be present in up to 96% cases and BRAF mutation in about half of the cases. Here, we report a patient with an unusual longstanding BRAF-negative Erdheim-Chester disease without bone lesions who developed pleuropulmonary and cardiac involvement.