Table 1

Clinical data,clinical diagnosis and pathological diagnosis of ECD patients

Figure 1

Pathological examination findings of right upper arm mass A-C：Foamy or rich in lipid tissue cells, fibrosis with inflammatory cells infiltration. D-G :Immunohistochemical staining high magnification.D：Langerin (individual +),E： CD1 α (individual +), F：S100（-），G：CD68（+）.

Figure 2

Pathological findings A,B: HE staining （×25, ×100） respectively, foamy or rich in lipid tissue cells, fibrosis with inflammatory cells infiltration.C-F Immunohistochemical staining CD34 (+), CD68 (+), according to (-), which CD1 alpha (individual +), S-100 (-), CD68 (+), AE1 / AE3 (-), which CD1 alpha (individual +), Langerin (-).

Figure 3

PET/CT findings of subcutaneous soft tissue lesions A:The subcutaneous hypermetabolism near the lateral canthus at the junction of the left anterior wall and lateral wall of the maxillary sinus in case 1 (thin arrow); B：A slightly thickened and hypermetabolic subcutaneous muscle in the left posterior neck in case 2 (thick blue arrow); C:A small nodular hypermetabolic subcutaneous muscle in the right posterior neck of in case 4 (thick red arrow).

Figure 4

MRI and PET/CT findings of Pituitary lesions A：T1WI enhancement sequence shows pituitary stalk enlargement and obvious enhancement in case 1(blue arrow); B：T1WI sequence shows loss of normal neuropituitary hyperintensity in case 1 (red arrow); C：Shows decreased PET /CT pituitary metabolism in case 2(green arrow)

Figure 5

CT, MRI and PET/CT findings of cerebellar lesions A：CT shows cerebellar atrophy in case 1 (curved arrow); D:18F-FDG-PET/CT shows uneven decreased metabolism in the pituitary gland (thick blue arrow), bilateral cerebellar hemispheres (red arrow), dorsal thalamus, and increased metabolism in the pontine dorsal tegmental region in case 1(green arrow); B, C, E, F：MRI T2-FLAIR sequence shows multiple patchy high signals in the brain stem (blue arrow) and bilateral cerebellar hemispheres in case 2(curved arrow); C：T1WI enhanced sequence shows obvious enhancement in small patches of some lesions in the right pontine brachium in case 2(blue arrow); E, F ：2 SWI sequence shows multiple small speckles of low signal intensity in bilateral basal ganglia and brainstem (blue arrow) in case 2.

Figure 6

X-ray、MRI and PET/CT findings of bone lesion A：X-ray showed typical signs of symmetrical bone sclerosis in the pelvis, femur and tibia of both lower limbs, blurred edge of cancellous sclerosis area, smooth bone cortex, without periosteal reaction and bone destruction like perforation or erosion. There was no surrounding soft tissue mass in case 2 (blue-red-green arrows). B： FDG-PET/CT showed vertebral body, upper and lower jaw bones, spinous process or interspinous ligament, SUVmax15.2-17.1 in case1 (blue arrow). C-D： MRI shows hyperintensity in the right infratemporal fossa soft tissue on T2WI, heterogeneous enhancement on T1WI, and hyperintensity with limited diffusion on DWI in case 1 (blue arrow).

Figure 7

X-ray、MRI and PET/CT findings of bone lesion A,B ：Initial X-ray of the humerus was false negative, and positive MRI showed high FS-T2WI signal in the medullary cavity of the middle and lower humerus in case 1(blue arrow); C,D： Osteolytic lesion, PET/CT showed osteolytic bone destruction in the right temporomandibular joint, and part of the bone cortex was blurred and discontinuous with increased metabolism. SUV max about 15.18, no surrounding soft tissue mass in case 5(blue arrow).

Figure 8

CT findings of other lesion A： The density of renal sinus soft tissue,with irregular shape and rough edge, and the CT value was about 13HU in case 2; B-C：With pericardial effusion and consolidation of the right lower lobe of the lung in case 3; D ：Left retroperitoneal mass with compression of the left renal vein in case 15.