Infantile mammary duct ectasia: a cause of bloody nipple discharge.

Bloody nipple discharge in infancy has been rarely reported in the medical literature. Its cause is unknown. We report a three-year-old male infant and a five-month-old female infant with bloody nipple discharge. Because of persistent bloody discharge, a subcutaneous mastectomy was performed in the boy; the problem resolved in the girl after a period of observation. The specimen showed histologic changes identical to those seen in adult mammary duct ectasia. All the endocrinologic work-up was normal. We suspect that bloody nipple discharge in infancy is underreported. This is a benign condition with histologic changes similar to adult mammary duct ectasia and if persistent, should be properly investigated; biopsy or excision are not indicated.