Accessory breast

Accessory breast, also known as polymastia, supernumerary breasts, ectopic breast tissue, or aberrant breast tissue, refers to the presence of extra breast tissue in addition to the normal pair of breasts. Accessory breasts are commonly found in the armpit and anterior axillary region, but can also appear around the normal breasts, abdomen, groin, and other areas. This condition is a congenital developmental abnormality of the breast caused by the incomplete regression or failure of regression of primitive mammary tissue during fetal development. It can also occur in males.