What happened, in summary

A 64-year-old woman had a 2.6 cm mass detected by screening mammography in the upper outer right breast. Biopsy showed grade 1–2 invasive mucinous carcinoma that was ER-positive, PR-positive, and HER2-negative.

She underwent right lumpectomy with placement of a BioZorb marker. Sentinel-node biopsy was negative, and postoperative radiation followed. Surveillance imaging continued after breast-conserving treatment.

Two years after lumpectomy, mammography showed a new density at the back of the absorbed BioZorb site. Additional views suggested a low-density process, and ultrasound found an echogenic mass in the same area. Although the appearance favored fat necrosis, the change required tissue confirmation because it was adjacent to the previous tumor bed.

Stereotactic biopsy showed amorphous material, a cyst wall, and a focus of fat necrosis. The pathology was considered concordant with the imaging findings, supporting a benign postoperative change rather than recurrent breast cancer. Her case demonstrates how BioZorb absorption and healing can create new findings that require biopsy during surveillance.