Use of shear-wave elastography to distinguish complex and complicated fibroadenomas from simple fibroadenomas

PURPOSE Simple fibroadenomas (SFAs), complex fibroadenomas (CFAs), and cellular fibroadenomas (CeFAs) are variants of fibroadenomas. Additionally, some degenerative, hyperplastic, and metaplastic changes may occur in fibroadenomas, forming complicated fibroadenomas. Distinctive ultrasonography (US) features in variants of fibroadenomas and complicated fibroadenomas have not been reported. Shear-wave elastography (SWE) can be applied to effectively discriminate between these variants and complicated fibroadenomas. In this study, we aimed to evaluate SWE findings to discriminate between SFAs and other variants. METHODS In total, 48 patients (26 with SFAs, 16 with CFAs, 3 with CeFAs, and 3 with complicated fibroadenomas) participated in this study. The lesions were classified into two groups according to histopathologic diagnoses. The SWE evaluation and lesion elasticity scores (E-max, E-mean, and E-min) were both assessed in m/s and k/Pa, respectively. Two observers measured E-max, E-mean, and E-min. Brightness (B)-mode US findings based on the Breast Imaging Reporting and Data System categorization and elasticity scores were recorded. In the statistical analyses, the chi-square test and non-parametric tests were performed. Fisher's exact test was used to compare independent groups, and Spearman's correlation coefficients were used to correlate the SWE data between the two observers. Additionally, receiver operating characteristic curves were analyzed to evaluate the diagnostic performance of the elasticity values. RESULTS The B-mode US features in both groups showed no statistical significance. The set of SWE values of both observers demonstrated strong statistical significance in discriminating between group 1 (SFAs) and Group 2 (CFAs, CeFAs, and complicated fibroadenomas). CONCLUSION As the fibroadenoma variants and complicated fibroadenomas have similar US findings, SWE in addition to a conventional B-mode examination can increase the diagnostic performance to discriminate SFAs from other complex and complicated forms of fibroadenomas.