Synopsis
Recognise fat necrosis after trauma, surgery or radiotherapy, correlate its evolving imaging and pathological appearances, and exclude malignancy when the clinical history does not fully explain the lesion.
- Fat necrosis is sterile inflammation and fibrosis after adipocyte injury and can follow blunt trauma, surgery, reconstruction, biopsy, anticoagulation or radiotherapy.
- It may present as a painless hard irregular lump, skin or nipple tethering, bruising or an incidental imaging abnormality that closely mimics carcinoma.
- A trauma history supports the diagnosis but does not prove it; patients may not recall injury, and cancer can coexist with or be mistakenly attributed to trauma.
Investigation priorities
Identify fat density, oil cyst, dystrophic calcification, distortion or a spiculated mass.
Management branches
Eight months after therapeutic mammoplasty, a patient notices a hard area beneath the lateral scar and fears recurrence.
- Map the mass and obtain the operation and pathology records, including resection cavity, reconstruction pattern and prior margin status.
- Perform diagnostic mammography and targeted ultrasound rather than judging the lesion from scar proximity or postoperative timing alone.