Breast development occurs in two phases, one during fetal life and the second during puberty. In fetal life a rudimentary organ with simple ducts develop under maternal stimulus. During puberty, further complex branching of ducts and glandular tissue forms which is divided into five stages.
Tanner stages of normal breast development
- stage I: an ill defined hyperechoic area is seen in retroareolar region
- stage II: a stellate hypoechoic area forms in the center of the echogenic retroarolar area which becomes clinically palpable
- stage III: the stellate or spider shaped hypoechoic area enlarges and there is increased echogenicity in its surrounding representing glandular tissue expansion
- stage IV: hyperechoic periareolar fibroglandular tissue is seen with a smaller prominent hypoechoic nodule in retroareolar region
- stage V: hyperechoic fibroglandular tissue with increased subcutaneous fatty tissue is seen giving the breast its contour. The central hypoechoic nodule is absent.