Ultrasonography of invasive lobular carcinoma of the breast: sonographic patterns and diagnostic value: report of 102 cases.

The aim of this study was to define the ultrasonographic (US) features of the invasive lobular carcinoma (ILC). For this purpose, the clinical histories and the mammographic and sonographic findings observed in 102 patients affected by documented ILC were retrospectively reviewed, and the role and value of US in the diagnosis of palpable and nonpalpable breast tumors were evaluated. At US, five proven tumors were not visualized (sensitivity: 95%), while the remaining 97 showed sonographic images that are considered typically malignant: irregular heterogenic, hypoechoic irregular masses in 94 cases, which were associated with posterior shadowing in 87. The presence of only a posterior shadowing was observed in three cases. There were 16 subclinical tumors, and in two of the four in which a mammography showed an indeterminate lesion, US demonstrated a malignant pattern. All the palpable tumors that were not detected mammographically were demonstrated by US. In 13 of the 102 patients (12.7%), the correct diagnosis of malignancy was established by US. On the basis of the data obtained, it is felt that because of its sensitivity and high specificity for malignancy, US plays a very important role in the diagnosis of ILC, whenever in a patient with positive clinical findings, the mammography is negative or the mammographic features are equivocal.