Abstract Fat necrosis is a benign nonsuppurative inflammatory process of adipose tissue. Occasionally fat necrosis may mimic a breast cancer clinically, mammographically, and sonographically. There have been some previous reports on the MR imaging of the fat necrosis. In some MR findings of fat necrosis, it was difficult to distinguish it from malignant lesions. We report a case of fat necrosis presenting the irregular enhancement with the non-enhancing area of central areas on MRI.