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Summary![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Fat necrosis of the breast is a benign nonsuppurative inflammatory lesion affecting the adipose tissue. It accounts for < 3% of all breast lesions and is usually the result of trauma (including blunt injury, surgery, or radiation) to the breast. Fat necrosis of the breast manifests as an ill-defined nontender breast mass; local skin changes may also be present. Age-appropriate breast imaging is indicated in all patients with a palpable breast mass. On mammography, fat necrosis may appear as an oil cyst; on ultrasound, it may appear as a breast mass of variable echogenicity. Clinical and imaging features can resemble those of breast cancer. If there is any suspicion of malignancy or if imaging is inconclusive, image-guided biopsy is indicated. Treatment is not usually required, but surgical excision should be considered if malignancy cannot be excluded, or imaging and pathology findings are discordant.
Epidemiology![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Etiology![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
- Often associated with soft tissue trauma [3]
- Surgery or radiation [2]
Clinical features![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
- Typically manifests as an ill-defined nontender breast mass
- Often periareolar in location; can also occur peripherally
- Breast skin retraction, erythema, and/or ecchymosis
Diagnostics![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Follow age-appropriate diagnostic workup for a palpable breast mass. The findings specific to fat necrosis of the breast are described here.
Imaging findings [2][4][5]
- Breast ultrasound: variable; may be solid or cystic and anechoic or hyperechoic [5]
-
Mammography [2][5]
- Fluid-filled oil cyst
- Coarse rim calcifications
- Spiculated mass
-
MRI breast with and without contrast (not routinely ordered) [2][5]
- Round or oval lesions with hypointense T1 signals when fat suppression is performed
- Irregular or spiculated mass
Image-guided biopsy
- Indication: clinical suspicion of malignancy [2]
-
Findings [5][6]
- Foam cells and multinucleated giant cells
- Necrotic fat cells
- Hemosiderin deposition and chronic inflammation
Imaging findings of fat necrosis (e.g., spiculated mass, calcifications) may resemble those of breast cancer. Biopsy is recommended if there is clinical suspicion of malignancy.
Treatment![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
- Expectant management is usually sufficient.
- Appropriate surveillance for benign or probably benign lesions [7]
- Consider surgical excision if:
- Malignancy can not be excluded
- Imaging and pathology findings are discordant