A 2-year-old female patient. The CT results show bone destruction accompanied with periosteal reaction in the left iliac bone, with discontinuous cortical and increased density of the medullary cavity. Surrounding muscle tissue is slightly swollen with a flaky low-density shadow (a, b). MRI shows an expansive destruction and soft tissue mass shadow in the left iliac bone, with equal T1 and slightly long T2 signal (c). The histological appearance of the iliac bone destruction shows a large number of eosinophilic granulocytes invasions (d) (red arrows indicate the site of iliac bone destruction).