RESUMEN
PURPOSE: We sometimes encounter remnant or regrowth of benign breast tumors diagnosed as Breast Imaging-Reporting and Data System (BI-RADS) C4 in follow-up breast ultrasound after previous vacuum-assisted core biopsy (VACB). We aimed to evaluate the factors that influence remnant or regrowth tumors at post-VACB site or adjacent tissue. METHODS: From January 2010 to December 2015, we analyzed 647 cases on follow-up. Patients were divided into two groups; group A was defined as patients without recurrent masses on breast ultrasonography during the follow-up period, and group B was defined as those with recurrent masses diagnosed as more than BI-RADS C4 on ultrasonography. RESULTS: Fibrocystic changes, proliferative disease without atypia, intraductal papilloma, apocrine cell change, atypical ductal hyperplasia, sclerosing adenosis, and radial scars were observed in 89.5% (n=579), 15.9% (n=103), 15.3% (n=99), 5.3% (n=34), 5.7% (n=37), 7.6% (n=49), and 6.3% (n=41) of patients, respectively. During the follow-up period, 85 patients were diagnosed as group B. Group B was significantly associated with proliferative diseases without atypia, sclerosing adenosis, and microcalcifications compared to group A (p=0.008, p=0.007, and p=0.001, respectively). After adjustment for confounding variables, group B was more significantly associated with proliferative breast diseases than group A (hazard ratio [HR], 0.558; 95% confidence interval [CI], 0.343–0.907; p=0.018). Furthermore, group B was more significantly associated with intraductal papilloma (HR, 0.571; 95% CI, 0.342–0.953; p=0.032). CONCLUSION: Previously diagnosed proliferative diseases without atypia or microcalcification at first VACB were significantly associated with recurrent breast tumor. Intraductal papilloma was also significantly associated with tumor regrowth.