Clinical Radiology (1987) 38, 31

Fat Necrosis of the Breast: An Unusual Complication of Lumpectomy and Radiotherapy in Breast Cancer A. Y. ROSTOM and M. E. E L - S A Y E D

Radiotherapy Department, St Luke's Hospital, GuildJbrd, Surrey

Fat necrosis is a weli-recognised complication of trauma to the breast. It has also been described following breast surgery. In this report, we describe four patients who developed a small tender nodule following excision and radiotherapy for early breast cancer. These were in or near the excision scar. Histology of the resected nodules revealed fat necrosis with no evidence of recurrence. It is recommended that in all cases when a tender, inflamed nodule in or adjacent to the excision scar is found, a biopsy should be carried out to distinguish between this condition and recurrence.

Fat necrosis of the breast is a well-recognised compli- cation of trauma to the breast (Clarke et al. 1983). In this report, we describe four patients who presented with this complication after wide local excision and radio- therapy. All patients received external irradiation using a 6°Co machine. Three patients received a dose of 4875 cGy in 15 fractions giving five fractions a fortnight. A four field technique was used: an internal mammary field, two opposing tangential fields to the breast and an anterior supraclavicular and axillary field. The fourth patient received 3900 cGy in six fractions over 35 days, using a three field technique (two opposing tangential fields to the breast and an anterior supraclavicular and axillary field).

CASE REPORTS

Case 1. A 71-year-old woman presented with a l cm diameter mass in the outer upper quadrant of the right breast. Wide local excision was done and post operative radiotherapy was given. Nine months later she complained of pain in the right breast and a tender hard mass, 5x2 cm in diameter , was found in the lateral upper quadrant . Tru-Cut needle biopsy was carried out and histology showed fat necrosis and radiation changes only. The pain, inf lammation and mass disappeared spontaneously. Thirty months later she complained of low back pain and was found to have multiple lung and bone secondaries with no evidence of local recurrence in the breast. She died 16 months later.

Case 2. A 67-year-old woman presented with a 3 cm diameter mass in the inner upper quadrant of the left breast. She was treated by excision and radiotherapy and remained well until 13 months later when she developed a tender inflamed mass, 4 cm in diameter and 3 cm away from the operation scar. Excision revealed fat necrosis and radiation changes with no evidence of carcinoma. Three months later a similar tender inflamed area appeared in the left axilla and further excision was carried out. On this occasion extensive fibrosis and radia- tion changes were noted as well as small abscess formation. Culture gave a very scanty growth of Staphylococcus albus. She was treated by appropriate antibiotics. Complete healing occurred and she died 3.5 years later of myocardial infarction.

Case 3. A 51-year-old woman presented with a 5 × 2.5 cm mass in the upper medial quadrant of the left breast. Wide local excision was carried out and post-operative radiotherapy given. Ten months later she presented with a 1.5 cm diameter tender subcutaneous nodule in

the middle of the operation scar. There were no overlying skin changes. Histology of the excised nodule and surrounding skin showed fibrosis and fat necrosis only. Unfortunately, she developed a wound infection with subsequent breakdown and sloughing of a large area of the skin over the breast. A simple mastec tomy was performed; the great o m e n t u m was mobilised and transposed to fill the defect, followed by delayed primary skin grafting with subsequent complete healing. A t the time of reporting, 5.5 years later, she remains well with no sign of recurrence or metastases.

Case 4. A 71-year-old woman presented with a 1.5 cm diameter mass in the medial upper quadrant of the right breast. Wide excision and post operative radiotherapy were carried out. Twelve months later she presented with a painless, mobile 1 cm diameter mass near the medial end of the excision scar. The histology of this revealed skin with an underlying zone of old fat necrosis adjacent to some suture material. She remains well 6 months after the second excision with no sign of recurrence or metastases.

DISCUSSION

Fifty per cent of women with fat necrosis of the breast give a history of trauma (Haagensen, 1971) but this was denied by all patients in the present series. Post-radia- tion endarteritis obliterans with subsequent ischaemia and necrosis of subcutaneous fat, or seepage of duct secretions into the surrounding tissues, may be factors in the pathogenesis of the condition. Fat necrosis of the breast has only been reported when radiotherapy has followed surgery and has not been seen with irradiation alone.

Fat necrosis following surgery and radiotherapy has been previously reported (Clarke et al., 1983) and was seen with smaller doses per fraction and total doses than in the present series. This would suggest that radiation dose and the technique of administration are not signifi- cant factors.

Fat necrosis of the breast may be mistaken for recur- rent carcinoma (Hadfield, 1929; Clarke et al., 1983) and we would recommend that in all instances where tender, inflamed masses develop adjacent to excision scars, a biopsy be obtained to distinguish between the two conditions.

REFERENCES

Clarke, D, Curtis, JL, Martinez, A, Fajard OL & Goffinet , D (1983). Fat necrosis of the breast simulating recurrent carcinoma after primary radiotherapy in the managemen t of early stage breast carcinoma. Cancer, 82, 442-445.

Gazet, JC, Rainsbury, RM, Ford, HT, Powles, TJ & Coombes , RC (1985). Survey of t rea tment of primary breast cancer in Great Britain. British Medical Journal, 290, 1793-1795.

Haagensen , CD (1971). Diseases of the Breast. 2nd edn, pp. 20~211. W.B. Saunders, Philadelphia.

Hadfield, G (1929). Fat necrosis of the breast. British Journal of Surgery, 17, 673.