Our radiological experience on B3 lesions: correlation between mammographic and MRI findings with histological definitive result

Abstract Purpose evaluate mammographic and MRI features in B3 lesions. Methods from 2011 to 2018, 139 patients with histologically proved B3 lesions who underwent mammography or/and MRI, were retrospectively reviewed. B3 lesions were classified in: ADH (atypical ductal hyperplasia), LN (lobular neoplasia), PL (papillary lesion), RS (radial scar), FEA (flat epithelial atypia), PT (phyllodes tumor) or mesenchymal lesion. Imaging features evaluated were: the presence of microcalcifications, mass and architectural distortions on mammograms and type of margins (circumscribed, irregular, spiculate), enhancement (mass-like, non-mass-like), size (≤15mm, >15mm) and kinetics curves (I, II, III) on MRI. The definitive histological results confirmed benign lesion or upgraded to malignancy and PPV was calculated. Results Histological classification of B3 lesions counted 45(32.37%) ADH, 12(8.63%) LN, 25(17.99%) PL, 5(3.61%) RS, 31(22.31%) FEA, 20(14.39%)PT and 1(0.70%) mesenchymal lesion. One-hundred-seven patients performed mammography and 38 MRI. In 90 cases(65%) the histological diagnosis confirmed B3, in 15 cases(11%) benign lesion and in 34 cases(24%) malignancy were found with best PPV for mesenchymal tumor (1), ADH (0.36) and FEA (0.4). Significant correlations comparing CNB groups and microcalcifications (P = 0.016) and presence of mass (P = 0.002), and comparing definitive histology with the presence of mass (P = 0.023), were found. Regards MRI, the morphology correlated with CNB groups (p=0.038); morphology (p=0.024), dimension (p=0.040) and kinetic curve (p=0.005) correlated with malignancy. Conclusions B3 category includes different entities, with various risk of malignancy; their heterogeneity is associated with specific mammographic and MRI features, although further confirmations are needed.