The mammographic spectrum of fat necrosis of the breast.

Fat necrosis of the breast is a benign condition that most commonly occurs as the result of minor breast trauma. The radiographic and clinical significance of fat necrosis of the breast is that it may mimic a breast malignancy, requiring biopsy for diagnosis. The mammographic appearance of fat necrosis ranges from a lipid cyst to findings suspicious for malignancy, including clustered microcalcifications, a spiculated area of increased opacity, or a focal mass. The changes of fat necrosis may be seen following blunt trauma, cyst aspiration, biopsy, lumpectomy, radiation therapy, reduction mammoplasty, breast reconstruction with a transverse rectus abdominis myocutaneous (TRAM) flap, implant removal, and anticoagulant therapy, as well as in patients without a relevant history. Fat necrosis may also be detected mammographically as an incidental finding in benign lipomas. It is important to recognize the mammographic spectrum of appearances of fat necrosis to avoid unnecessary biopsy and to avoid overlooking breast cancer.