The Rightful Role of MRI after Negative Conventional Imaging in the Management of Bloody Nipple Discharge

Abstract Nipple discharge is a frequent presenting complaint at breast clinics. Bloody nipple discharge ( BND ) has the highest risk of malignancy, albeit low. If mammogram and ultrasound are unrevealing, central duct excision ( CDE ) has been considered the gold standard in its management. Magnetic resonance imaging ( MRI ) has been widely confirmed as a highly sensitive test for detection of breast cancer, with an accompanying high negative predictive value. This article presents a retrospective review of patients with BND and negative conventional imaging, comparing outcome of patients who went directly to CDE without MRI to those patients who underwent preoperative MRI . Of 115 patients who underwent mammography and US alone prior to CDE , eight cancers were detected (seven ductal carcinoma in situ [ DCIS ] and 1 IDC , 7 mm [T1b]; incidence: 7%). Of 85 patients who underwent conventional imaging followed by MRI prior to surgery, eight cancers were detected (all DCIS ; incidence: 9.4%), seven of which were identified by MRI . The one false‐negative MRI had subtle findings which, in retrospect, were misinterpreted; however, a clinically apparent nipple lesion prompted surgical biopsy. Of 56 patients with a negative or benign MRI , CDE was negative for malignancy in all but that one patient. Sensitivity and specificity were 87.5%/71.4%. Positive predictive value and negative predictive value ( NPV ) were 24.1%/98.2%. MRI should be performed in all patients with BND and negative conventional imaging. The extremely high NPV of MRI suggests that a negative study could obviate CDE in most patients unless overriding clinical factors prevail.