Sustained Inflammation of Breast Tumors after Needle Biopsy.

Introduction: Needle biopsy is essential for definitive diagnosis of breast malignancy. Significant histologic changes due to tissue damage have been reported in solid tumors. This study investigated the association between time from needle biopsy and inflammation in breast tumors.

Methods: A total of 73 stage I-II invasive breast cancer cases diagnosed by image-guided needle biopsy who had surgery as their first definitive treatment were retrospectively analyzed. Time from biopsy to surgical excision ranged from 8 to 252 days. Histological sections of surgically resected tumors with a visible needle tract were reviewed by histologic evaluation. Data were analyzed by McNemar's test for proportional differences, and the Benjamini-Hochberg procedure was used to assess the association between immune cell prevalence and clinical variables.

Results: Characteristic histology changes, including foreign body giant-cell reaction, synovial-cell metaplasia, desmoplastic repair changes, granulation tissue, fat necrosis, and inflammation, were frequently detected adjacent to the needle tract. Spatial comparison indicated that a higher proportion of cases had neutrophils, eosinophils, and macrophages adjacent to the needle tract than tumors distant from it. The presence of inflammatory cells adjacent to the needle tract was not associated with time from biopsy or subtype. Still, plasma cells were associated with residual carrier material from biopsy markers.

Conclusion: Macrophages and eosinophils are highly abundant and retained adjacent to the needle tract regardless of time from the biopsy.