Supernumerary Nipples & Breast Tissue
A frequent developmental variation in human anatomy involves additional breast tissue. Most supernumerary nipples can be identified during standard abdominal and chest examinations because of their unique distribution along the milk line. These lines extend from slightly beyond the underarm region, tracing down the chest and abdomen, reaching the groin area, and terminating near the inner thighs close to the groin. The breast formation originates from these tissue lines, while the remaining tissue regresses naturally.
EMBRYONIC DEVELOPMENT
The process of breast development initiates at approximately the fourth week of gestation, characterized by the emergence of dual lines of glandular tissue known as the milk line (or mammary ridge). In certain instances, incomplete regression of the mammary ridge can transpire during embryonic development, leading to the formation of supplementary (supernumerary) nipples and/or breast tissue. Although these occurrences predominantly take place along this ridge, they can occasionally manifest in other body regions. This phenomenon is observed in both males and females. An extra nipple, areola, and/or glandular tissue might be present anywhere along this line. Having multiple instances of these features is not uncommon. According to studies, extra nipples tend to be more prevalent in males, and there are instances when their occurrence exhibits a pattern in families.
PRESENTATION
Accessory breast tissue can manifest in the form of a complete breast when it includes all components—nipple, areola, and glandular tissue. If mammary tissue lacks a nipple or areola, it can give rise to a lump or swelling beneath the skin. An extra nipple, which might resemble a freckle, a mole, or a dimple, could also resemble a typical nipple, albeit usually smaller in size. Frequently, the presence of accessory nipples or breast tissue goes unnoticed until hormonal fluctuations render them more noticeable. In certain cases, a new mother might not even realize the existence of accessory breast tissue until she observes milk secretion from what appears to be a "freckle" or a skin pore. Additional nipples typically emerge just below the primary breasts or within the underarm region, while supplementary mammary tissue is generally situated in the underarm vicinity.
Tail of Spence
Not to be confused with the breast tissue that normally extends into the underarm region, the Tail of Spence is directly linked to the primary ductal system of the breast. Supernumerary breast tissue lacks any functional connection to the main breast structure. Despite its proximity to the breast, it might be situated near the breast, in the underarm area, or anywhere else along the milk line.
WHAT DOES THIS MEAN?
Because this tissue is classified as breast tissue, it carries the potential to encounter comparable issues as any standard breast tissue would. This encompasses concerns like inflammation, mastitis, abscesses, cysts, benign growths, or even malignant alterations. While the accessory nipple or supplementary breast tissue can be eliminated through surgical means, this step is only deemed necessary when it leads to complications. However, some individuals do opt for the removal of accessory breast tissue or nipples for aesthetic reasons.
Breastfeeding is encouraged as there should be none to minimal impact on your breastfeeding journey.
Blum A, Roehm S. Accessory nipple looks like dermatofibroma in dermoscopy. Arch Dermatol. 2003;139(7):948-949