Ultrasound Findings of Mammary Duct Ectasia Causing Bloody Nipple Discharge in Infancy and Childhood.

Bloody nipple discharge in infancy and childhood is extremely rare, and mammary duct ectasia is the most common etiology. Ultrasound (US) findings of mammary duct ectasia include dilated ducts and tubular anechoic lesions that may contain echogenic debris in the subareolar region. However, mammary duct ectasia may show variable US findings, which are not well described in the literature. We report 3 cases of mammary duct ectasia in infancy and childhood with variable imaging findings, including complex cystic and solid lesions. Detailed initial clinical and US findings and serial follow-up US images are described.