Vacuum-Assisted Breast Biopsy and Post-Biopsy Scarring: Implications for Imaging Interpretation.

Background/Objectives: Breast cancer is the most common malignancy among women worldwide. Vacuum-assisted breast biopsy (VABB) has emerged as a minimally invasive alternative to surgical excision, but it may cause post-biopsy scarring that could mimic or obscure malignancies on follow-up imaging. This study aimed to evaluate the imaging characteristics, evolution, and clinical implications of post-VABB scar formation. Methods: We conducted a retrospective study of patients who underwent mammographic or magnetic resonance imaging-guided VABB at our institution between January 2010 and December 2020 and whose follow-up report describes a post-biopsy scar. Patients with malignant or high-risk lesions requiring subsequent surgery or prior breast surgery were excluded. Post-biopsy follow-up mammograms and ultrasounds were reviewed by a fellowship-trained breast radiologist for scar formation, visibility across imaging modalities, and evolution over time. Statistical analysis was performed to assess associations between scar detection and patient or lesion characteristics. Results: Thirty-seven patients (39 lesions) with documented post-biopsy scarring on follow-up imaging reports met the study inclusion criteria. The mean age at biopsy was 51.97 ± 12.40 years. Lesions were almost equally distributed between the right and left breasts, with 19 cases involving the right breast (48.7%) and 20 cases involving the left breast (51.3%). Most cases did not need any workup, except for six cases, where two required further biopsy and four required short-term follow-up. No malignancy was detected during the available follow-up or additional evaluation. Twenty-two scars regressed over time. The estimated mean time to scar regression was 69.47 months. Conclusions: Post-biopsy scarring was documented in a small subset of our institution's VABB cases over the study period and may resemble malignant findings, particularly on tomosynthesis. Awareness of typical scar characteristics, careful documentation of biopsy sites, and correlation with clip markers are essential to avoid unnecessary interventions.