Axillary Masse, is it an Ectopic Mammary Gland?

Ectopic breast tissue or super numerary mammary gland is a congenital condition characterized by the development of mammary tissue along the embryonic milk line. This condition Occurs in 0.4-6% of the general population. The most common site of development of super numerary mammary gland is the axillar region. Axillary ectopic breast tissue may provide a diagnostic challenge, as other benign and malignant lesions occur in this area. We report a case of 18 years-old girl presenting an axillary masse considered firstly as an ectopic mammary gland. Ultrasound aspect and axillary MRI correct the diagnosis and lead to provide specific management of this tumor.