Sonography of fat necrosis of the breast: correlation with mammography and MR imaging

Fat necrosis (FN) of the breast is a benign nonsuppurative inflammatory process of the adipose tissue. The radiologic appearance ranges from benign to suspicious for malignancy; therefore, it is very important to know the distinguishing radiologic features of FN on different modalities. Mammography is more helpful in identifying FN than ultrasonography in most of the cases, and MRI may also be used to rule out malignancy as an adjunct to mammography and sonography. Even when modern diagnostic modalities are used, biopsy may still be unavoidable for some cases. In conclusion, an accurate history and familiarity with the radiologic findings are crucial to recognizing FN and avoiding unnecessary interventions.