Recognizing pitfalls in early and late migration of clip markers after imaging-guided directional vacuum-assisted biopsy.

Directional vacuum-assisted biopsy has become an irreplaceable tool in the management of suspicious mammographic lesions. Often, the entire lesion is removed and clips are used to localize the biopsy site. Postbiopsy mammograms are used to determine the adequacy of clip placement and the location of the clip. Clip displacement from the site of deployment is not an uncommon finding. Clips may migrate within the same quadrant where the lesion was located or to another quadrant of the breast. Clip migration may occur immediately after biopsy or may be seen on later follow-up mammograms. Clip migration can affect interpretation of mammographic findings and localization for future surgery. It should not be assumed that the clip is correctly located at the biopsy site on subsequent mammograms. It is essential to recognize the relationship of the clip to the targeted lesion to ensure accurate localization of lesions that require surgical excision. Copyright RSNA, 2004