Purpose: To describe the sonographic (US) features associated with ultrasonography BI-RADS category 4 lesions that have a benign histopathological outcome.
Methods: One hundred seventy-two histopathologically proven benign lesions in 169 patients, which had been classified as BI-RADS category 4 with ultrasonography, were retrospectively evaluated. Ultrasonography and histopathology findings were analyzed. The frequency of sonographic findings according to the histopathological diagnosis was determined.
Results: Among the 172 lesions, there were 66 (38%) fibroadenomas, 31 (18%) sclerosing adenoses, 24 (14%) fibrocystic changes, 16 (9%) mastitis/inflammations, 9 (5.5%) intraductal papillomas, 8 (5%) focal fibroses, 4 (2.5%) atypical ductal hyperplasias, 4 (2.5%) fat necroses, 2 (1%) phyllodes tumors, 1 (0.5%) tubular adenomas, 1 (0.5%) epidermal inclusion cysts, and 6 (3.5%) "other benign lesions." The most frequent sonographic findings were heterogeneity, indistinct margin, microlobulation in fibroadenomas; heterogeneity, irregular-indefinite margin, and antiparallel orientation in sclerosing adenosis; heterogeneity, microlobulation, and acoustic shadowing in fibrocystic changes.
Conclusions: BI-RADS category 4 lesions demonstrate more than one suspicious ultrasonography feature, and biopsy is necessary to diagnose malignancy captured in 33% of lesions in this study. At this time, any lesion with more than one suspicious BI-RADS US feature cannot avoid a diagnostic biopsy.
Copyright © 2012 Wiley Periodicals, Inc.