As a superficial organ, the breast contains abundant adipose tissue that helps maintain its shape. When fat necrosis occurs, it can produce local manifestations strikingly similar to breast cancer, warranting attention. The incidence of breast fat necrosis generally accounts for about 1-2% of benign breast diseases and is more commonly seen in young women with ample breasts. It can occur in all age groups but is most frequently observed in young and middle-aged individuals.

bubble_chart Etiology

Trauma is the primary cause of breast necrosis. Most cases have a clear history of trauma, such as impact, falls, compression, surgery, or puncture. However, in a few cases, the trauma is so minor that patients cannot recall any history of injury. Due to the structural characteristics of adipose tissue—such as its delicate and fragile nature, as well as its relatively poor blood supply—trauma can lead to impaired blood flow and the rupture and necrosis of fat cells. Additionally, the expansion of modern lifestyles, increased physical labor, and greater participation in sports can all raise the likelihood of trauma to superficial soft tissues, including the adipose tissue of the breast.

bubble_chart Clinical Manifestations

There are often external injuries. In the early stages after injury, the local skin may appear slightly red or have ecchymosis, with grade I tenderness. If necrosis is extensive or the injury involves larger blood vessels, large patches of ecchymosis may appear, followed by a slightly painful or painless lump under the skin at the injury site. After central liquefaction of the lump, a soft area or fluctuation may develop. Upon local incision or puncture, dark red or bloody granular necrotic fatty tissue can be observed. If the lesion is close to the breast skin or superficial subcutaneous layer, subcutaneous nodules are often palpable. If there is skin adhesion or the lesion is near the nipple or areola, manifestations such as nipple inward invasion may occur. When necrotic fat is within the breast parenchyma, poorly defined nodules are often palpable. Some cases may also present with axillary lymphadenopathy.

After breast trauma, the appearance of ecchymosis on the breast skin followed by nodules often leads to a diagnosis.

bubble_chart Treatment Measures

Treatment measures: Early application of physiotherapy to promote absorption, and topical application of powder for invigorating blood and resolving stasis. If the central part of the mass liquefies, fluctuates, or shows signs of secondary infection, incision and drainage should be performed. Some cases may require antibiotics. If trauma is uncertain and breast cancer cannot be ruled out, the affected tissue should be excised for pathological examination.

bubble_chart Differentiation

For cases with breast lumps, skin adhesion, nipple retraction, and axillary lymph node involvement but unclear trauma history, differentiation from breast cancer should be considered. The latter typically occurs in older individuals with progressive disease progression, no history of trauma, and absence of skin ecchymosis. Fine-needle aspiration biopsy and pathological examination can establish the diagnosis. During biopsy or fine-needle aspiration, lipid-laden cells are often observed without atypical cells, which helps exclude breast cancer. X-ray imaging can aid in diagnosis. In a few cases, lipid-containing cysts or patchy calcifications may be observed in the affected area, which differ from the sand-like calcifications seen in breast cancer.