The disappearing clip: an unusual complication in MRI biopsy

Abstract

MRI-guided biopsies are being increasingly used for otherwise occult breast lesions. Clip migration has been reported however, to the best of our knowledge, there have been no documented cases of entire disappearance of a marker clip. Absence of the postbiopsy marker clip was noted when our patient returned for preoperative hook-wire localisation even though accurate clip placement had been confirmed on the post-MRI biopsy mammogram.

Figure 1

(A and B) Screening mammograms (mediolateraloblique, MLO and craniocaudal, CC views) show no suspicious mass lesion, distortion or microcalcification. (C) Post contrast MRI (90 s) image showing suspicious focal linear enhancement (long arrow). The lesion was sonographically occult and the patient therefore proceeded to MRI-guided biopsy. (D) MRI-guided biopsy performed for the enhancing lesion using 9 G needle and vacuum assistance. (E and F) Post-MRI biopsy check mammograms (MLO and CC view) confirm MRI clip (short arrow) at the site of biopsy with adjacent haematoma.

Figure 2

(A and B) Check mammogram following failure to locate the MRI clip for hook-wire localisation on the day of surgery confirms absence of the clip. (C and D) Ultrasound demonstrates scarring at the site of previous MRI biopsy. This site was targeted for hook-wire localisation. (E–H) Post hook-wire mammograms (F and H) with the corresponding post-MRI biopsy images (E and G) placed alongside to confirm hook-wire location at the site of the previous lesion. The arrow in (E) and (G) demonstrates the clip in the post-MRI biopsy images and that in images (F) and (H) demonstrates the skin marker at the site of hook-wire insertion.