Background Erdheim-Chester disease (ECD) is a rare, inflammatory disease of unknown etiology. It is characterized by the xanthogranulomatous infiltration of tissues by foamy, CD 68+, CD1a-, S-100- macrophages . ECD almost invariably involves long bones but frequently features extra-skeletal involvements. Cardiovascular and neurological ECD are associated with the worst prognosis .
Objectives To compare the role of echocardiography and cardiac cine Magnetic Resonance Imaging (MRI) in detecting the heart involvement and functional impairment in ECD.
Methods Eight sequential patients with histologically-proven ECD, underwent echocardiography and morphological and ECG-gated MRI with mitral/tricuspid transvalvular flow evaluation and study of myocardium viability after infusion of paramagnetic contrast agent
Results Echocardiography disclosed a cardiac mass in 4 out of 8 studied patients (50%). Detected mass had no specific ultrasound feature, except for right atrioventricular sulcus localization. The mean major diameter of the cardiac mass was 31.00 mm (range 25.00 – 37.00 mm). Pericardial effusion was detected in 6 out of 8 patients (75%), always circumpherential. Mean pericardial effusion at its greatest width was 17.60 mm (range 5.00 – 30.00 mm). Left ventricle (LV) and right ventricle (RV) morphology and function were within the normal range. Cardiac magnetic resonance, disclosed the presence of cardiac ECD involvement in 8 out of 8 studied patients (100%). In all cases a cardiac mass was present, involving the right atrioventricular sulcus, right atrial free wall and right coronary artery origin. Mean major mass diameter was 26.25 mm (range 15.00 – 40.00 mm). Cardiac mass had distinctive radiological features in all cases: dishomogeneous signal intensity in STIR sequences, with focal areas of hyperintensity consistent with active inflammation, due to focal infiltration by pathological, xantogranulomatous tissue and hypointense areas consistent with fibrosis; rapid enhancement during perfusion sequences and peculiar high signal intensity in late enhancement sequences. At cine MRI pericardial effusion was circumpherential in all cases, and its mean greatest width was 20.00 mm (range 10.00 – 50.00 mm). All patients had pericardial thickening, mean thickness was 4.38 mm (range 3.00 – 9.00 mm). RV EDV was reduced in 6 out 8 patients (75%), mean value was 110.14 mL. RV diastolic function was impaired in all patients. LV EF was within normal range in all patients, mean EF was 63% (range 53 – 78%). LV EDV was reduced in 4 out of 8 patients (50%) and increased in 1 patient.
Conclusions Echocardiography is less sensitive than cardiac MRI (50% vs 100%) in detecting pathological tissue. This is probably due to the right chambers localization, usually worse studied with a trans-thoracic approach, besides the intrinsic limits of trans-thoracic ultrasound primarily operator dependence and risk of suboptimal acoustic window. Cardiac MRI is a fundamental tool for monitoring patients affected by ECD and eventually for modifying patients therapy.
Haroche J et al. Erdheim-Chester disease. Rheum Dis Clin North Am 2013
Haroche J et al. Cardiovascular involvement, an overlooked feature of Erdheim-Chester disease: report of 6 new cases and a literature review. Medicine 2004
Acknowledgements This work was supported in part by a grant from the Italian Ministry of Health to LD (GR-2009-1594586).
Disclosure of Interest : None declared