Fat necrosis of the breast

Last updated: November 22, 2022

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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.

Epidemiological data refers to the US, unless otherwise specified.

Follow age-appropriate diagnostic workup for a palpable breast mass. The findings specific to fat necrosis of the breast are described here.

Imaging findings [1][3][4]

  • Breast ultrasound: variable; may be solid or cystic and anechoic or hyperechoic [4]
  • Mammography [1][4]
    • Fluid-filled oil cyst
    • Coarse rim calcifications
    • Spiculated mass
  • MRI breast with and without contrast (not routinely ordered) [1][4]
    • Round or oval lesions with hypointense T1 signals when fat suppression is performed
    • Irregular or spiculated mass

Image-guided biopsy

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.

  • Expectant management is usually sufficient.
  • Appropriate surveillance for benign or probably benign lesions [6]
  • Consider surgical excision if:
    • Malignancy can not be excluded
    • Imaging and pathology findings are discordant
  1. Guirguis MS, Adrada B, Santiago L, Candelaria R, Arribas E. Mimickers of breast malignancy: imaging findings, pathologic concordance and clinical management. Insights Imaging. 2021; 12 (1). doi: 10.1186/s13244-021-00991-x . | Open in Read by QxMD
  2. Tan PH, Lai LM, Carrington EV, et al. Fat necrosis of the breast—A review. The Breast. 2005; 15 (3): p.313-318. doi: 10.1016/j.breast.2005.07.003 . | Open in Read by QxMD
  3. Taboada JL, Stephens TW, Krishnamurthy S, Brandt KR, Whitman GJ. The Many Faces of Fat Necrosis in the Breast. AJR Am J Roentgenol.. 2009; 192 (3): p.815-825. doi: 10.2214/ajr.08.1250 . | Open in Read by QxMD
  4. Kerridge WD, Kryvenko ON, Thompson A, Shah BA. Fat necrosis of the breast: a pictorial review of the mammographic, ultrasound, CT, and MRI findings with histopathologic correlation. Radiol Res Pract. 2015; 2015 : p.1-8. doi: 10.1155/2015/613139 . | Open in Read by QxMD
  5. D’Alfonso TM, Ginter PS, Shin SJ. A Review of Inflammatory Processes of the Breast with a Focus on Diagnosis in Core Biopsy Samples. Journal of Pathology and Translational Medicine. 2015; 49 (4): p.279-287. doi: 10.4132/jptm.2015.06.11 . | Open in Read by QxMD
  6. ACOG. Practice Bulletin No. 164 Diagnosis and management of benign breast disorders. Obstetrics & Gynecology. 2016; 127 (6): p.e141-e156. doi: 10.1097/aog.0000000000001482 . | Open in Read by QxMD

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