Background: Accessory breast tissue is residual breast tissue that persists due to the failure of regression of mammary streaks in embryogenesis. It is essential to diagnose accessory breast tissue because it can harbor all the pathological conditions that can occur in normally located breast. Cases of accessory breast with benign cystic changes, mastitis, abscesses, fibroadenomas, and carcinomas are documented. Duct ectasia is, however, a rare occurrence in accessory breast and only a few cases have been previously reported. Case Presentation: A 38 year female, presented with marked and extensive duct ectasia involving almost whole of the right breast parenchyma and bilateral accessory axillary breasts with infrequently observed findings on mammography and ultrasonography. Conclusion: This case report highlights the imaging features of duct ectasia involving the accessory axillary breasts which is a rare occurrence. Awareness of imaging features of this entity may help in early diagnosis to allow adequate management and also to prevent its complications like the formation of abscesses and fistulae.

Keywords: Accessory breast, Fibroadenoma, Duct ectasia, mammography, ultrasonography, case report.