Off-label application of the breast expander magnet: An alternative approach to enable localisation and removal of ferromagnetic subcutaneous foreign bodies

Objective: Included foreign bodies of a metallic nature are commonly found. They are often small, asymptomatic, with few or non-visible scars or even clinically invisible. Sometimes the patient does not remember their existence. The condition is benign and does not require special attention, unless a magnetic resonance imaging scan is necessary. Indeed, magnetic field interactions could pose significant risks, and the procedure is typically contraindicated unless the ferromagnetic foreign body (FFB) has been previously removed. For such purposes, the magnet that is commonly used in breast and plastic surgery units for breast expanders port injection site identification could represent a time-saving and cost-effective solution. Methodology: This paper presents an alternative technique based on off-label application of the breast expander magnet to localize FFBs. Results: Between April 2023 and June 2023, the breast expander magnet allowed successful pre-operative localisation and intra-operative guidance for removal of FFBs in four clinical cases. The post-operative ultrasound confirmed the absence of metal residues after the procedure in all cases. Conclusion: Off-label application of the breast expander magnet allows for FFB pre-operative localisation and safe intra-operative surgical guidance, thus representing a promising off-label application of the device. After surgical removal of FFBs, the magnetic resonance imaging is allowed without any risk.