Calcifying aponeurotic fibroma in a girl: MRI findings and their chronological changes

Calcifying aponeurotic fibroma (CAF) is a rare benign tumor that typically develops in the fascia and tendons. On MRI, CAF usually shows isointensity on T1WI and heterogeneous high intensity on T2WI. We report a case of 17-month-old girl with CAF on her right ankle. MRI showed an usual signal intensity for CAF. At 3 years and 4 months of age, MRI revealed hyperintense nodules on T1WI and T2WI inside of the CAF. These fatty areas corresponded to coarse calcified nodules on CT. Radiologists should be aware of the fact that fat-like signals can appear in CAF on MRI.