“…The extra-skeletal sites reported to be involved are mediastinum or pericardium, heart, lungs, gastrointestinal tract, kidneys, retroperitoneum, central nervous system, skin and orbits [9]. The lung involvement shows a constellation of findings strongly suggesting ECD: smooth interlobular septal thickening, centrilobular nodular opacities, multifocal regions of ground-glass attenuation, fissural thickening and pleural effusions [11]. Microscopically ECD is characterised by the presence of aggregates of foamy histiocytic infiltrates with fibrosis and thickened bone trabeculae [3,6,7].…”