Diagnostic accuracy of breast MRI compared with conventional imaging, in the evaluation of patients with suspicious nipple discharge

Purpose: To determine the role and the diagnostic accuracy of breast Magnetic Resonance Imaging in the evaluation of patients with suspicious discharge from the nipple. Methods: 79 patients with suspicious nipple discharge underwent 3 Tesla MRI. Images were acquired with T2-IDEAL sequences, diffusion-weighted sequences as well as 3D T1-weighted sequences before and after the administration of 0.1 mmol/kg of gadobenate dimeglumine. MRI findings were classified according to Breast Imaging Reporting and Data System criteria as benign (BIRADS 1-2-3) or malignant (BIRADS 4-5). Reference diagnoses were based on histologic samples obtained at surgery for 51 patients and on clinical and instrumental follow-up over 24 months for 28 patients. Results: MRI identified 32 cases of BIRADS 4-5, 27 of which were found to be malignant at histological examination. In the 47 cases classified as BIRADS 1-2-3, 17 lesions were confirmed as benign by definitive histological examination, 2 lesions were found to be a malignant tumor and 28 patients had negative follow-up at 24 months. Sensitivity, specificity and diagnostic accuracy of MRI were respectively 93.1%, 90% and 91.1% with a positive predictive value of 84.3% and negative predictive value of 95.7%. The performance of MRI was also evaluated in comparison of positive cases of mammography and ultrasound. Conclusion: Breast MRI is an accurate method in the evaluation of patients with suspicious nipple secretion. A negative MRI can direct patients to follow-up rather than surgery. Keywords Magnetic resonance imaging, Nipple discharge, Breast cancer, Breast imaging