Diagnosis of the intraductal component of invasive breast cancer: assessment with mammography and sonography.

OBJECTIVE: The aim of this study was to investigate mammographic and sonographic features and their sensitivities for depiction of the intraductal component associated with invasive ductal carcinoma (IDC). METHODS: During a 1-year period, 132 patients with IDC underwent surgical treatment. All patients underwent mammography and high-resolution sonography, and the findings were reported according to the American College of Radiology's Breast Imaging Reporting and Data System lexicon. Tumors were classified as "pure IDC" and "IDC with an intraductal component" by histopathologic evaluation. We compared mammographic and sonographic features between the above 2 groups and attempted to correlate them with histopathologic findings. We also investigated separate and combined sensitivities, specificities, and accuracies of both mammography and breast sonography for showing intraductal components. Finally, imaging measurements were compared with pathologic measurements. RESULTS: One hundred four (79%) of the 132 IDCs contained an intraductal component. Patients with IDC with an intraductal component showed calcifications on mammography and showed an echogenic halo, duct dilatation, calcifications, and increased vascularity in surrounding tissue on sonography more frequently than patients with pure IDC. The sensitivities of mammography, sonography, and their combined assessment for detection of an intraductal component were 55%, 80%, and 86%, respectively. The combined assessment (r = 0.90) measured the extent of the tumor more accurately than mammography (r = 0.71) or sonography (r = 0.79) separately. CONCLUSIONS: Combined assessment with mammography and sonography offers more accurate information for the presence of an intraductal component and the extent of a tumor than each separate assessment.