Ultrasonographic Features of Benign Adenomyoepithelioma of the Breast

OBJECTIVE The purpose of this study was to evaluate the ultrasonographic features of benign adenomyoepithelioma of the breast. MATERIALS AND METHODS Between 2005 and 2009, five patients had histologically confirmed adenomyoepithelioma of the breast. We retrospectively evaluated the ultrasonographic findings of the tumors in correlation with the pathology, and reviewed medical records. RESULTS The clinical manifestations included a palpable mass in three patients, while mammographic screening helped detect abnormalities in two patients. Ultrasonograms showed masses with an oval (n = 3) or irregular (n = 2) shape, with uncircumscribed (n = 4) or relatively well-circumscribed (n = 1) margins, as well as with a hypoechoic (n = 3) or a complex echoic (n = 2) internal echo texture. Three patients had focal ductectasia adjacent to the mass. The ultrasonographic assessments were classified as Breast Imaging Reporting and Data System (BI-RADS) category 4A, with low suspicion of malignancy in two cases, and as category 4B, with intermediate suspicion of malignancy in three cases. The pathology revealed benign adenomyoepithelioma in all patients. CONCLUSION Benign adenomyoepitheliomas appear as solid or complex echoic masses with suspicious malignant ultrasonographic features, which may be associated with adjacent ductectasia. Although adenomyoepithelioma is a rare breast tumor, awareness of its sonographic features will be helpful for the differential diagnosis from other tumors.