Evaluation of Pathologic Nipple Discharge: What is the Added Diagnostic Value of MRI?

To determine the diagnostic value of magnetic resonance imaging (MRI) for the evaluation of patients with pathologic nipple discharge.

We performed a retrospective review of women with nipple discharge who underwent breast MRI between January 1, 2004, and December 31, 2013. Radiographic findings, pathology results, and clinical notes were reviewed. Sensitivity, specificity, positive predictive value, and negative predictive value of MRI were calculated.

Over a 10-year period, 103 women (mean age 46 years, range 25-72 years) underwent MRI for evaluation of nipple discharge. Ninety-one patients (88 %) underwent surgical excision or had clinical and/or radiographic follow-up at least 2 years after presentation and thus comprise the study population. Eleven (30 %) of 37 patients with MRIs coded as American College of Radiology Breast Imaging-Reporting and Data System (BI-RADS) 4 of 5 were diagnosed with ductal carcinoma in situ (n = 6) or invasive adenocarcinoma (n = 5). Seven (64 %) of 11 patients diagnosed with malignancy had a negative mammographic and sonographic workup. None of the patients with MRIs coded as BI-RADS 1, 2, or 3 was diagnosed with malignancy immediately after presentation or during the 2-year follow-up period. The sensitivity and specificity of MRI for the detection of malignancy were 100 % (11 of 11) and 68 % (54 of 80), respectively. The positive predictive value and negative predictive value were 37 and 100 %, respectively.

MRI is a valuable additional diagnostic tool for the evaluation of pathologic nipple discharge when conventional imaging is negative. A negative MRI in this symptomatic population may obviate the need for duct exploration and excision.