Erdheim-Chester disease: radiographic findings in five patients

We present the case histories of five patients with Erdheim-Chester disease, a rare lipoidosis that has several typical radiographic features. In all the patients, the diaphyses and metaphyses of the extremities demonstrated a symmetric pattern of diffuse or patchy increased density, a coarsened trabecular pattern, medullary sclerosis, and cortical thickening. The epiphyses were spared in four patients and partially involved in one. The axial skeleton was involved in one patient. Radiotracer ^99mTc accumulated in areas of radiographic abnormalities in all patients. In one patient, MRI demonstrated an abnormal signal, corresponding to radiographic abnormalities. The signal was hypointense to muscle on T1-weighted sequences and heterogeneously hyperintense and hypointense to normal bone marrow on T2-weighted sequences. Xanthogranulomatous lesions infiltrated the retroperitoneum in one patient, the testes in one patient, the eyelids in one patient, and the orbits in two patients.