ABSTRACT
The base of the adult female breast is fairly fixed, but the overall dimension and the position of the nipple is variable in the extreme. The base lies from the lateral sternal edge to the mid-axillary line, and extends from the second to the sixth ribs and overlies pectoralis major for the most part with small extensions over serratus anterior, the upper rectus sheath and external oblique muscles of the anterior abdominal wall. An extension of mammary tissue often extends into the axilla as the tail. The mature female breast is composed of many terminal duct lobular units that drain into branched ducts, eventually coalescing into a dozen or so major ducts opening on to the nipple. It should be noted that the distribution of ducts and tissue is not always congruous, i.e. breast tissue at the 6 o’clock position does not necessarily drain through the 6 o’clock nipple duct. The nipple is surrounded by a pigmented areola, itself ringed by elevated sebaceous glands known as tubercles of Montgomery. The ductolobular tissue of the breast is relatively sparse in the non-lactating breast, the majority of the breast volume is due to the interposed fatty tissue and it is the variations in the amount of adipose tissue that gives rise to the variations in size of the female breast.The breast is supported by a series of fibrous bands passing from the deep chest wall to the dermis – the ligaments of Astley Cooper.
