MRI for assessment of pathologic nipple discharge: is it mandatory?

Benign breast lesions is the most common cause of nipple discharge; however, a rare but major cause is breast cancer. This study assesses the superadded value of MRI in diagnosing causes of pathologic nipple discharge. Ninety-three patients with pathologic nipple discharge were evaluated by sonomammography and DCE-MRI. Sonomammography and MR imaging features were analyzed and correlated with the histopathology. Histopathology revealed 69 benign, three high-risk, and 21 malignant lesions. Simply dilated ducts and presence of a mass on US examination as well as non-mass enhancement and STIR signal changes on MRI were of statistically significant probability in differentiation between benign and malignant causes of pathological nipple discharge (p value = 0.017 and 0.001) and (p value ≤ 0.001). Sensitivity and specificity of mammogram and ultrasound in differentiation between benign and malignant causes of pathologic nipple discharge were 71.4% and 54.2% respectively with positive predictive value of 31.2%,negative predictive value of 86.7%, and accuracy of 58.1%. MRI gave higher sensitivity and specificity of 100% and 83.3% with positive predictive value of 63.6%, negative predictive value of 100%, and accuracy of 87.1%. Magnetic resonance imaging is superior to sonommagraphy in diagnosis of pathologic nipple discharge and we recommend it in special situations.