Adding Ultrasound to the Evaluation of Patients with Pathologic Nipple Discharge to Diagnose Additional Breast Cancers: Preliminary Data

The aim of this study was to assess the malignancy yield of ultrasound Breast Imaging Reporting and Data System (BI-RADS) classification and the diagnostic value of adding ultrasound to diagnosis of breast cancer in patients with pathologic nipple discharge. Of 267 patients with pathologic nipple discharge seen from February 2003 to March 2011, 198 with histopathologic confirmation and follow-up data were included. Ultrasound images and mammograms were analyzed according to BI-RADS. The malignancy rate for each BI-RADS category and the difference in diagnostic performance resulting from the addition of ultrasound to mammography were calculated. Of the 198 enrolled patients, 34 were diagnosed with a malignancy. The malignancy rates obtained with the addition of ultrasound to mammography were 0.0% (0 of 27) for category 1, 5.9% (1/17) for category 2, 9.4% (5/53) for category 3, 21.5% (20/93) for category 4 and 100% (8/8) for category 5. The malignancy rates for mammography alone were 7.7%-9.0% for categories 1-3, 68.5% (13/19) for category 4 and 100.0% (5/5) for category 5. Adding US to mammography did not significantly increase sensitivity compared with mammography alone. Other diagnostic performance markers such as specificity and positive predictive value were not improved. Among patients for whom mammograms were available, ultrasound detected 5 breast cancers (26.3%) in addition to the 19 breast cancers found by positive mammography. Although it did not increase overall diagnostic performance in patients with pathologic nipple discharge, addition of ultrasound to mammography did detect an additional 26.3% of malignant lesions.