Secretory carcinoma of the breast: sonographic features

The purpose of this series was to evaluate the sonographic features of secretory carcinoma of the breast.

Between 1994 and 2006, 9 patients had histologically confirmed secretory carcinoma of the breast in our institution, and 6 of them underwent breast sonography. We retrospectively evaluated the sonographic findings of the patients in correlation with other available images and reviewed the clinical records.

Clinical manifestations were a palpable mass (n=3), a bloody nipple discharge (n=1), and screening-detected abnormalities (n=2). Breast sonograms showed masses with a round or oval (n=5) or tubular (n=1) shape, with relatively well-circumscribed (n=2) or partially microlobulated (n=4) margins, and with a hypoechoic (n=4) or an isoechoic (n=2) internal echo texture. Most lesions were single nodules (n=3) or groups of nodules (n=2) measuring 1 cm or smaller, except 1 mass measuring 3.5 cm with axillary lymph node metastasis. Two cases had associated ductectasia. Sonographic assessments were classified as Breast Imaging Reporting and Data System category 3 in 2 cases, category 4A in 3 cases, and category 4B in 1 case.

Secretory carcinoma of the breast is frequently shown as a small benign-looking nodule or group of nodules or sometimes as an intraductal lesion with a low clinical stage on sonography. Although secretory carcinoma is a rare breast malignancy, awareness of its sonographic features will be helpful for the differential diagnosis.