Seat-belt trauma of the breast in a pregnant woman causing milk-duct injury: a case report and review of the literature

Abstract

Injury to the milk-duct following a road traffic accident has not been reported in the literature. This case report describes a 25-year-old postpartum lady with massive swelling of the breast due to milk-duct injury and collection of milk within the breast. We describe the possible mechanism of milk-duct injury, its presentation and management, and also review the literature on seat-belt injury to the breast.

Case history

A 25-year-old woman driver was involved in a collision with another vehicle. She was 34 weeks’ pregnant and was wearing a seat belt. Examination of her abdomen revealed bruising and tenderness. Due to the suspicion of placental abruption, an emergency caesarean section was carried out. At operation no intra-abdominal injury was noted and a healthy baby was delivered. Her other injuries included a fracture of the right clavicle and bruising to the left breast.

On the 4th postpartum day, she complained of significant pain and discomfort in her left breast. While she could breast feed successfully from the right breast, she was unable to express any milk from the left side. The left breast was considerably tender and swollen with the overlying skin being shiny and taut (Fig. 1). An ultrasound scan of the left breast revealed a collection of thick turbid fluid and on aspiration about 500 ml of blood-stained milk was obtained resulting in considerable symptomatic relief. An underlying injury to the milk ducts was suspected and the patient was advised to stop breast feeding in order to reduce milk formation and leakage into the breast parenchyma. The patient refused and 24 h later, the left breast was again swollen and painful. A further 400 ml of milk was aspirated and reluctantly she now agreed to stop feeding from the right breast. To suppress further milk production, she was given cabergoline 250 μg twice daily for 2 days. She required another four aspirations of milk from the left breast. By the 10th postpartum day, the swelling had settled completely. At 1 month postpartum, the patient remained well with no further pain, swelling or infection.

Figure 1.

Appearance of left breast on day 4.

Discussion

The severity of breast injuries following road traffic collisions can range from a small bruising in the breast to an avulsed breast.¹ The injuries usually result from compression of the breast tissue between the bony thorax and the seat belt as the torso decelerates suddenly and shearing stresses incurred by the soft tissues due to rotation of the trunk.² These result in the appearance of one of these effects, either alone or in combination: (i) friction burns or bruising; (ii) traumatic fat necrosis giving rise to breast lumps clinically indistinguishable from breast cancer; (iii) subcutaneous rupture of the breast parenchyma; and (iv) breast haematoma.³ The first two features are the most common. Clinically, fat necrosis may be asymptomatic or it may result in an indurated mass.¹ The mammographic appearance of fat necrosis includes a spectrum of findings, such as lipid cysts, focal areas of increased density and calcifications of various sizes and morphologies that are suspicious of malignancy.⁴ In many patients, a fine-needle cytology or core biopsy is required to exclude a malignant process.

Injury to the milk duct following a road traffic accident has not been reported in the literature. In our patient, the mechanism of injury is probably due to the rapid decelerating forces along with rotational stresses of the body causing the milk ducts to shear from the nipple. An ultrasound scan is essential to exclude haematoma or milk collection from simple engorgement of the breast in the immediate post-natal period. In large collections, prompt aspiration is crucial for rapid symptomatic relief and also protects the skin of the breast from developing ischaemic changes. Breast feeding from the opposite breast should be discontinued, as the suckling of milk or milk expression continues to stimulate both breasts to form milk and, thereby, leakage of milk from the damaged ducts into the breast parenchyma as we noted in our patient. Cabergoline is a dopamine-receptor agonist drug that suppresses lactation⁵ and is a useful adjunct to cessation of breast feeding for rapid suppression of lactation, as observed in our patient.

Multiple aspirations are necessary until milk suppression is complete and it is extremely important that absolute aseptic precautions are observed because there is risk of transmitting infection and converting a sterile milk collection into an abscess.

Conclusions

Seat-belt injury of the breast can have different presentations. A palpable or radiologically detected suspicious mass will require triple assessment. Milk duct injury is rare but should be suspected in postnatal patients who present with swelling of the breast. Ultrasound examination of the breast and aspiration will help to differentiate simple breast engorgement from milk collection. Cessation of breast feeding is necessary along with pharmacological suppression of lactation to prevent rapid re-accumulation of milk in the breast parenchyma. Multiple aspirations may be required and strict asepsis during aspiration is absolutely crucial.