Axillary Supernumerary Breast: A Clinical Image

Abstract

Accessory breast tissue, also known as polymastia, refers to the presence of ectopic mammary tissue along the embryonic mammary ridge, with the axillary region being the most common site of presentation. The most widely used classification is that proposed by Kajava in 1915, which describes eight types depending on the presence or absence of nipple, areola, and glandular tissue.

The prevalence is estimated to range between 2% and 6% in the female population, and up to 20–33% of cases may be bilateral.

Although it is generally a benign condition, a malignancy risk of approximately 0.3–0.6% has been reported; therefore, its recognition is clinically relevant. Currently, the treatment of choice for symptomatic cases or for aesthetic reasons is surgical excision.