REVIEWFat necrosis of the breast—A review
Introduction
Fat necrosis is a benign non-suppurative inflammatory process of adipose tissue which was initially described in the breast in 1920.1, 2 Hadfield described it as “an innocent lesion of the breast presenting itself most often in women between the fourth and fifth decades, frequently as a stony-hard tumour firmly fixed to the skin, often resembling an early cancer so closely that a wide resection of the breast has been performed”.3
It is important to diagnose fat necrosis because it often mimics carcinoma of the breast. The aim of this paper is to review the clinical, pathological and radiological features of fat necrosis of the breast which distinguishes it from breast cancer.
Section snippets
Epidemiology
The incidence of the disease is estimated to be 0.6% in the breast, representing 2.75% of all benign lesions.1, 2, 3, 4 Fat necrosis is found in 0.8% of breast tumours and 1% of breast reduction surgery cases.5 The average age of patients is 50 years.1, 2, 3, 4
Aetiology
The aetiological factors include trauma (21–70%),1, 2, 3, 4 radiotherapy,6, 7, 8 anticoagulation (warfarin),9 cyst aspiration, biopsy, lumpectomy, reduction mammoplasty, implant removal, breast reconstruction with tissue transfer,10 duct ectasia and breast infection. Other rare causes include polyarteritis nodosa, Weber-Christian disease and granulomatous angiopanniculitis. In some patients, the cause is unknown.11
Pathogenesis
Fat necrosis is a sterile, inflammatory process which results from aseptic saponification of fat by means of blood and tissue lipase.12 It varies in appearance depending on the stage of the process. It is recognised histologically as fat-filled macrophages and foreign body giant cells surrounded by interstitial infiltration of plasma cells.13
After trauma to the breast, haemorrhage occurs within a surgical cavity, or extravasate into the parenchyma. Blood dissects along the fibrous planes of
Clinical features
Clinical presentation of fat necrosis can range from an incidental benign finding to a lump highly suggestive of cancer.16, 18 In most cases it is clinically occult; however, it can present as single or multiple smooth, round, firm nodules or irregular masses. It may be associated with ecchymosis, erythema, inflammation, pain, skin retraction or thickening, nipple retraction and lymphadenopathy simulating carcinoma.10, 16, 19, 20
Hadfield3 described 66% of lesions as being stony hard. Up to 52%
Fine needle aspiration cytology (FNAC)
FNAC is reported to have a high sensitivity and specificity—87% and 99%, respectively.22, 23
Using FNAC as a diagnostic tool enables rapid results particularly in a ‘one-stop’ clinic setting. FNAC can decrease the number of excision biopsies.22, 23 However, the diagnosis of fat necrosis using FNAC is limited by inadequate samples24 and repeated attempts may be necessary to achieve a confident result. FNAC is reliable in collaboration with a good history of trauma and close follow-up in
Mammography
The mammographic appearance of fat necrosis include normal appearance (9%), discrete round or oval radiolucent oil cyst with thin capsule (27%), thickening and deformity of skin and subcutaneous tissue (16%), focal mass (13%), and ill-defined spiculated mass (4%).5 Oil cysts may be associated with uniform continuous eggshell calcification (27%). There may also be multiple clustered pleomorphic microcalcifications (4%) suspicious of malignancy.10, 19, 28 The most common mammographic findings are
Discussion
The management of fat necrosis continues to be challenging in practice. Even with modern diagnostic modalities, fat necrosis of the female breast can still be difficult to diagnose. In patients who have undergone breast conservation surgery or reconstruction for breast cancer, fat necrosis must be distinguished from cancer recurrence. Hence in specific cases, needle core biopsy is required to confirm diagnosis.
Although there is a definite association with trauma, surgery or biopsy of the
References (44)
- et al.
Fat Necrosis of the female breast: report of one hundred test cases
Am J Surg
(1947) - et al.
Fat necrosis of the female breast—Hadfield re-visited
Breast
(2001) - et al.
Fatty tissue breast lesions
Clin Imag
(2003) - et al.
Fat necrosis of the breast: an unusual complication of lumpectomy and radiotherapy in breast cancer
Clin Radiol
(1987) - et al.
Warfarin-induced complete bilateral breast necrosis
Br J Plast Surg
(1992) - et al.
Fat necrosis of the breast: clinical, mammographic and sonographic features
Eur J Radiol
(2001) - et al.
Fat necrosis of breast: a potential pitfall in breast MRI
Clin Imag
(2002) - et al.
Case report: MR imaging of fat necrosis of the breast associated with lipid cyst formation following conservative treatment for breast carcinoma
Clin Radiol
(1996) - et al.
MR imaging of the breast after surgery for breast cancer
Magn Reson Imag Clin N Am
(1994) - et al.
Traumatic fat necrosis of the female breast
Ann Surg
(1920)
Fat necrosis of the breast
Br J Surg
Fat necrosis following breast irradiation for carcinoma; clinical presentation and diagnosis
Breast
Fat necrosis of the breast simulating recurrent carcinoma after primary radiotherapy in the management of early stage breast carcinoma
Cancer
The mammographic spectrum of fat necrosis of the breast
Radiographics
Fat necrosis of the breast: mammographic, sonographic, computed tomography, and magnetic resonance imaging findings
Curr Probl Diagn Radiol
Noniatrogenic breast trauma
Breast Dis
MR findings of a breast oil cyst containing a fat-fluid level. A case report
Acta Radiol
Mechanisms and functions of cell death
Annu Rev Cell Biol
Roles of heat-shock proteins in innate and adaptive immunity
Nat Rev Immunol
Lipid cyst: classic and atypical appearances
AJR Am J Roentgenol
Breast imaging case of the day
Radiographics
Fat necrosis in the breast: sonographic features
Radiology
Cited by (92)
Surgical management of breast fat necrosis: Multi-institutional data analysis of early outcomes and risk factors for complications
2024, Journal of Plastic, Reconstructive and Aesthetic SurgeryThe treatment of symptomatic fat necrosis: A review and introduction of a new treatment algorithm
2023, Journal of Plastic, Reconstructive and Aesthetic SurgeryDeep inferior epigastric perforator (DIEP) flap safety profile in slim versus non-slim BMI patients: A systematic review and meta-analysis
2022, Journal of Plastic, Reconstructive and Aesthetic SurgeryBenign Breast Disorders
2022, Obstetrics and Gynecology Clinics of North America