ACR Appropriateness Criteria® Evaluation of Nipple Discharge: 2022 Update.

The type of nipple discharge dictates the appropriate imaging study. Physiologic nipple discharge is common and does not require diagnostic imaging. Pathologic nipple discharge in women, men, and transgender patients necessitates breast imaging. Evidence-based guidelines were used to evaluate breast imaging modalities for appropriateness based on patient age and gender. For an adult female or male 40 years of age or greater, mammography or digital breast tomosynthesis (DBT) is performed initially. Breast ultrasound is usually performed at the same time with rare exception. For males or females 30 to 39 years of age, mammography/DBT or breast ultrasound is performed based on institutional preference and individual patient considerations. For young women less than 30 years of age, ultrasound is performed first with mammography/DBT added if there are suspicious findings or if the patient is at elevated lifetime risk for developing breast cancer. There is a high incidence of breast cancer in males with pathologic discharge. Men 25 years and older should be evaluated using mammography/DBT and ultrasound added when indicted. In transfeminine (male-to-female) patients, mammography/DBT and ultrasound are useful due to the increased incidence of breast cancer. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.