Determination of extent and activity with radionuclide imaging in Erdheim-Chester disease

Erdheim-Chester disease usually involves the diaphyseal and metaphyseal reg ions of tubular bones and various visceral organs. A 56-year-old woman pres ented with the histologically confirmed diagnosis of Erdheim-Chester diseas e. A Tc-99m MDP bone scan revealed the entire extent of the skeletal diseas e and showed unusual involvement of the epiphyses and axial skeleton. In ad dition to MRI, a Ga-67 citrate scan including SPECT showed extensive soft-t issue infiltration of different organs. Both Tc-99m MDP and Ga-67 scintigra phy are useful tools in determining the distribution of this rare disease.