Can we be sure about a radiological diagnosis of fat necrosis of the breast?

AIMS

We performed a review of the clinical, mammographic and sonographic findings of fat necrosis in a group of patients who presented with a lump in the breast. We aimed to show that, in the light of a non-specific combination of findings, an ultrasound-guided core-biopsy (CB) is a safe, quick and useful test to confirm the diagnosis. The procedure makes it possible to reassure the patient of the true identity of the lesion, thus avoiding the need for surgical excision or follow-up investigations.

MATERIALS AND METHODS

We undertook a retrospective review of the clinical presentation, imaging findings and subsequent management of 23 histologically proven cases of fat necrosis. All patients had presented to a specialist breast clinic with a breast lump.

RESULTS

Only 52% of patients had a definite history of trauma. Clinical examination intimated that the lump was possibly malignant in 22%, while 4.5% were probably malignant. Fifty-seven per cent of mammograms were completely normal, however ultrasound showed an abnormality in 100%. Of these 100%, 74% were interpreted as possibly malignant. The diagnosis of fat necrosis was histologically confirmed by ultrasound-guided needle core biopsy, performed at the time of initial presentation. All patients were subsequently discharged. The mean time interval from investigation and biopsy to final diagnosis and discharge of the patient was 5.9 days.

CONCLUSION

We show that fat necrosis often has a confusing clinical presentation. Imaging by either mammography or ultrasound is often inconclusive and ultrasound-guided core biopsy will confirm the diagnosis sparing patients unnecessary radiological follow-up or surgical excision.