Katrina Nesta Glazebrook MBChB, Presenter: Nothing to Disclose

Kathleen Rae Brandt MD, Abstract Co-Author: Nothing to Disclose

Carol Reynolds MD, Abstract Co-Author: Nothing to Disclose

To determine the imaging findings following placement of a water-soluble polyethylene glycol-based hydrogel that contains a central metallic marker (HydroMARK, Biopsy Sciences Florida) during stereotactic or ultrasound guided biopsy of malignant and benign breast lesions, with pathologic correlation.

Retrospective review was performed of stereotactic and ultrasound guided biopsies for key word “Hydromark” from January 1 2009 to February 16 2011, with IRB approval. Mammogram, MRI and ultrasound imaging after biopsy and at the time of localization, and any follow-up imaging through March 29, 2011, were reviewed (follow-up ranging from 2 to 13 months).

206 clips deployed in 203 women were included. Biopsies were performed stereotactically (n = 129) and sonographically (n =77). Immediate post biopsy mammogram (n=202) showed clip to be within 5mm of biopsied lesion in 91% of cases, with faint tubular density around the clip in 26% (53/202). MRI (n=10) showed tubular high T2 signal mass with occasional thin rim of enhancement. 98 patients went to surgery: 44% mastectomy, 56% lumpectomy  (65% localized sonographically, 31% mammographically, 2% palpable). The hydrated gel was seen mammographically as a tubular soft tissue mass, and sonographically as an anechoic tubular mass. Histologically there were large cyst like spaces lined by histiocytes with pseudostratification adjacent to the gel. Follow up mammograms (n=21), ultrasound (n=9) and MRI (n=3), were obtained 2 to 13 months following clip placement. Mammographically, a soft tissue tubular mass; sonographically, a tubular anechoic mass; MRI, a high T2 signal tubular mass were seen surrounding the metallic clip in all cases.

HydroMARK hydrogel begins to hydrate within 1 hour of placement and is easily visualized mammographically and sonographically at the time of localization. On MRI, a tubular, high T2 signal mass is seen with occasional thin rim of enhancement. Histologically, cystic like spaces are lined by histiocytes with pseudostratification. Mammographic and sonographic tubular masses are present over 13 months following placement. This should be recognized by radiologists to prevent errors in interpretation and unnecessary invasive procedures.

Radiologists must be aware of mammographic, sonographic and MRI findings present following Hydromark clip placement, especially on followup for benign biopsies to prevent errors in interpretation.

Glazebrook, K, Brandt, K, Reynolds, C, Mammographic, Sonographic, and MR Findings Following HydroMARK Clip Placement during Ultrasound and Stereotactic Breast Biopsies with Pathologic Correlation.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11006159.html