Introduction: Some benign breast pathologies have clinical and/or imaging features that mimic malignant disease. This pictorial essay describes the mammographic, digital breast tomosynthesis (DBT), and ultrasound (US) features of breast pathologies with imaging findings suspicious for malignancy and histopathologic confirmation of benignity. Material and Methods: This case series presents women with breast lesions that mimic malignancy. BI-RADS 4 or 5 categories on mammography, DBT, and US were included. The history, clinical manifestations, and histopathologic findings with diagnostic confirmation of inflammatory breast pathology, proliferative breast pathology, or benign breast tumors are described. Results: We evaluated nine cases of breast lesions with suspected malignancy, describing mammography, DBT, and US findings, with clinical and pathologic correlations. Breast abscess, granulomatous mastitis, fat necrosis, stromal fibrosis, sclerosing adenosis, pseudoangiomatous stromal hyperplasia (PASH), tubular adenoma, granular cell tumor, and desmoid-type fibromatosis are presented. The differential diagnoses of the benign pathologies simulating malignancy were based on correlating imaging and clinicopathologic findings. Conclusion: The nine breast pathologies described had no pathognomonic radiologic findings for the diagnosis of benignity. Breast biopsy and histopathologic examination were recommended when features suspicious of malignancy were found on mammography, DBT, and/or US.

Introduction:A breast nonmass (NM) on ultrasound (US) is associated with a wide spectrum of breast pathologies. The aims of this study were to (1) re-evaluate the ultrasonographic features of breast NM using a standardized lexicon and ( 2) identify the ultrasonographic features that predict malignancy in NM and its histopathologic confirmation. Material and Methods: Women with ultrasonographic report of breast NM with BI-RADS category 3, 4, or 5 and diagnosis by biopsy or ultrasonographic follow-up over 24 months were included. The following features of breast NM were assessed by ultrasound: echogenicity, distribution, orientation, and associated findings according to the standardized lexicon of the fifth-edition update of the ACR BI-RADS. Univariate and multivariate analyses were performed. Results: Seventy-two women with breast NM were included; 53 (73.6%) had confirmed benign NM, 3 (4.2%) had benign with upgrade potential (