MRI diagnosis and follow-up of chest wall and breast desmoid tumours in patients with a history of oncologic breast surgery and silicone implants: A pictorial report.

INTRODUCTION: Breast and chest wall desmoid tumours can cause debilitating symptoms and deformity. The mutilating effects of surgical treatment have prompted a shift to medical treatments and even to a wait-and-see approach. This study sought to highlight specific characteristics of breast and chest wall desmoid tumours on long-term follow-up by sequential MRI scans.

METHODS: Thirty-two breast MRI scans from six patients with chest wall or breast desmoid tumours followed up for up to 6 years were retrospectively reviewed.

RESULTS: All patients underwent breast surgery prior to the development of the desmoid tumour. Five of the patients had reconstruction or augmentation using silicone implants. Two desmoids were treated primarily with surgery, three with medical means and one is under wait-and-see approach. On MRI, tumours appeared either oval and lobulated (chest wall) or spiculated with architectural distortion (breast). Chest wall desmoids demonstrated both an enhancing high-T2-signal component and a non-enhancing low-T2- signal component. The histologically defined phases during the course of desmoid tumours (progression, regression, residual disease) could be demonstrated by corresponding MRI changes in each of the components.

CONCLUSIONS: Magnetic resonance imaging delineates the complex infiltrative features of chest wall and breast desmoid tumours. In tumours with a bright cellular enhancing and dark collagenous non-enhancing component, treatment response may be predicted by changes on serial T2-weighted sequences, beyond the tumour-dimension-based RECIST assessment alone.