The role of bone scintigraphy in patients with Erdheim-Chester disease

Erdheim-Chester disease (ECD) is a rare disorder that has been reported few er than 60 times in the literature. Although clinical findings seem to be s pecific at first sight, histologic classification remains unclear. It has n ot been decided whether ECD is part of the spectrum of histiocytoses or whe ther it may be a lipid storage disorder or even a primary macrophage cell d isorder, although it does show a distinct histologic pattern. However, the clinical appearance alone shows several typical features, rendering the dia gnosis very probable if present. This article illustrates the importance of bone scanning in ECD, because the scintigraphic pattern of involved skelet al sites may in themselves lead to the diagnosis. Several differential diag noses are considered. The importance of bone scintigraphy as an imaging met hod in patients with an unclear diagnosis is discussed, as exemplary in ECD , as is its role for the detection of sites of skeletal involvement in othe r diseases.