Abstract
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Learning Objectives 1. To showcase how integration of findings across radiologic subspecialties and imaging modalities allows for the identification of a multisystemic disease. 2. To provide a brief review of the pathology, clinical presentations, and common imaging findings in Erdheim-Chester disease. 3. To demonstrate the utility of PET/CT for evaluation of response to therapy.
Erdheim-Chester disease is a rare form of non-Langerhans cell histiocytosis, characterized by multisystemic infiltration of lipid-laden macrophages with adjacent fibrosis. Imaging from a series of four cases of Erdheim-Chester disease will be displayed, highlighting findings across radiologic subspecialties. Features include trabecular thickening and osteosclerosis on bone radiographs, bone marrow invasion on MRI, increased peri-epiphyseal uptake of long bones on Tc-99m bone scintigraphy, perirenal rind-like soft tissue density (FDG-avid), hazy periaortic soft-tissue mantle with sparing of the lower abdominal aorta, and orbital soft-tissue mass. In addition, PET/CT is a valuable tool for assessing disease activity and therapeutic response. A series of PET/CT images will display an example disease response to therapy. Recognition of the imaging characteristics highlighted in this presentation may help reduce delay in diagnosis, enable earlier disease treatment, and provide an example of disease response to therapy.