To evaluate the mammographic and ultrasonographic findings of mucocele-like tumors.

Twelve breast lesions from 1994 through 2004, coded as mucocele or mucocele-like tumors, were retrieved from the surgical pathology database files at our institution. Eleven of the patients had undergone mammography, and sonography had been performed in all 12 patients. We retrospectively reviewed the mammographic, sonographic and pathologic findings.

The mammographies showed calcifications alone (n=6), calcification with mass or asymmetric density (n=3), and normal mammogram (n=2). The shapes of the calcifications were pleomorphic (n=4, 44.4%), amorphous (n=3, 33.3%) and round (n=2, 22.2%). Sonography was performed in all patients (n=12) and showed cysts (n=8), cystic mass (n=2), tubular hypoechoic structure (n=1) and hypoechoic mass (n=1). Pathologic examination revealed 5 cases of benign mucocele-like tumor that included epithelial hyperplasia without atypia (n=2) and atypical ductal hyperplasia (n=4), and 3 cases of associated intraductal carcinoma. Calcification was more frequently detected in the mucocele-like tumors with atypical ductal hyperplasia or intraductal carcinoma than in the benign tumors. Pleomorphic calcification was only visualized in those cases involving atypical hyperplasia or intraductal carcinoma. Of the 9 cases of calcification seen in the mammograms, 7 cases (77.8%) were detected in the associated sonograms and all were located within the lesion.

The most common mammographic finding of mucocele-like tumors was segmentally distributed pleomorphic or amorphous calcifications, and the most common sonographic finding was cyst or cystic mass.