The role of 18FDG, 18FDOPA PET/CT and 99mTc bone scintigraphy imaging in Erdheim–Chester disease

Highlights • Erdheim–Chester disease (ECD) is a rare non-Langerhans cell histiocitosis, characterized by multisystemic xanthogranulomatous infiltration by foamy histiocytes. Etiology and pathogenesis are still unknown and only about 500 cases are related in the literature. • Multifocal nature of involvement in ECD can produce a wide variety of clinical signs. In our experience, neurological involvement is associated with mortality in all cases. Characteristic long bone osteosclerosis was a quasi-pathognomonic finding in bone scintigraphy. • To the best of our knowledge, the 18FDOPA-PET/CT not seem useful in the initial staging of ECD based on a single case report. • Bone scintigraphy and the 18FDG-PET/CT that were particularly useful in despite systemic involvement, locate the optimum site for biopsy and treatment response evaluation. In this context, a baseline 18FDG-PET/CT with an optional bone scintigraphy may help in monitoring the disease and could be considered when patients were incidentally diagnosed and periodically follow-up 18FDG-PET/CT must be performed in the follow up to evaluate the treatment response.