A 7-year-old girl with an eosinophilic granuloma. (A) Axial T1-weighted image showing an isointense small round mass within the occipital bone (arrow). (B) An axial T2-weighted image reveals that the mass is hyperintense (arrow). (C) Axial DW imaging reveals that the mass is slightly hyperintense with a high ADC value (circled area: ADC = 1.50 × 10−3 mm2/s) (arrow). (D) Axial enhanced T1-weighted image showing the lesion with marked enhancement (arrow).