A Case of Incidentally-diagnosed Erdheim-Chester Disease

Abstract

Erdheim-Chester disease (ECD) is a rare multisystemic non-Langerhans cell histiocytosis that may be clonal and inflammatory in origin. The hallmark of the disease is infiltration of various organ systems by CD68+/CD1a- histiocytes containing foamy lipid-laden inclusions. The manifestations and course of the disease are variable and depend on the organ systems that are affected. Patients may be asymptomatic or may develop life-threatening complications, including myocardial infarction. The most common clinical manifestation is lower extremity bone pain. Imaging manifestations of the disease include symmetric osteosclerosis of the distal long bones, circumferentially "coated" aorta, pleural and pericardial thickening/fluid, and perirenal encasement. Treatment for the disease is evolving, particularly with the use of molecular BRAF inhibition. We present a case of a patient with ECD initially suspected based on the imaging manifestations.

Keywords: erdheim-chester disease.

Figure 1. Computed tomography (CT) findings in of patient with Erdheim-Chester disease

A. Composite image with axial precontrast (left image) and axial contrast-enhanced (right image) CT shows enhancing soft tissue (arrows) partially surrounding the descending thoracic aorta. B. Oblique coronal contrast-enhanced CT better shows the extent of peri-aortic soft tissue spanning the entire descending thoracic aorta. C. Axial contrast-enhanced abdominal CT shows symmetric perirenal infiltration by soft tissue (arrows).

Figure 2. Femoral radiographs of patient with Erdheim-Chester disease

Composite image of the distal femur with frontal radiograph (left image) and lateral radiograph (right image) shows patchy sclerosis (arrows) in the distal femoral metadiaphysis. The contralateral femur (not shown) had similar findings.