Nipple discharge is a common symptom in clinical practice, representing the third leading breast complaint, after pain and lumps. It is usually limited and has a benign etiology. The risk of malignancy is higher when the discharge is uniductal, unilateral, spontaneous, persistent, bloody, or serous, as well as when it is accompanied by a breast mass. The most common causes of pathologic nipple discharge are papilloma and ductal ectasia. However, there is a 5% risk of malignancy, mainly ductal carcinoma in situ. The clinical examination is an essential part of the patient evaluation, allowing benign nipple discharge to be distinguished from suspicious nipple discharge, which calls for imaging. Mammography and ultrasound should be used together as first-line imaging methods. However, mammography has low sensitivity in cases of nipple discharge, because, typically, the lesions are small, are retroareolar, and contain no calcifications. Because the reported sensitivity and specificity of ultrasound, it is important to use the correct technique to search for intraductal lesions in the retroareolar region. Recent studies recommend the use of magnetic resonance imaging in cases of suspicious nipple discharge in which the mammography and ultrasound findings are normal. The most common magnetic resonance imaging finding is non-mass enhancement. Surgery is no longer the only solution for patients with suspicious nipple discharge, because short-time follow-up can be safely proposed.

Keywords: Nipple discharge; Mammography; Ultrasonography; Magnetic resonance imaging.

OBJECTIVE: To describe the indications for breast magnetic resonance imaging (MRI) at a referral center for breast cancer in Brazil. MATERIALS AND METHODS: This was a retrospective study in which we reviewed the clinical records, including physician requests and patient questionnaires, of women who underwent breast MRI between 2014 and 2018 at a referral center for the diagnosis and treatment of breast cancer in the city of Belo Horizonte, Brazil. RESULTS: The most common indication for breast MRI was as a complement to mammography/ultrasonography (in 43.6% of cases), followed by breast cancer staging (in 25.1%), the screening of patients at high risk (in 17.4%), the evaluation of breast implants (in 10.1%), and the evaluation of the response to neoadjuvant chemotherapy (in 3.8%). CONCLUSION: Although there is strong evidence supporting the use of breast MRI, mainly for the screening of high-risk patients, the imaging method is underutilized in Brazil.

Keywords: Breast neoplasms/diagnostic imaging; Magnetic resonance imaging; Early detection of cancer/methods.