Benign and malignant diseases of the breast

Abstract

Appreciation of the embryological development, anatomy, and physiology of the breast is critical for the rational evaluation and treatment of both benign and malignant breast disease. The breast develops from the ectodermally derived milk streak. Early in fetal life, the milk streak extends from the axilla to the pubis (Fig. 96.1). At the end of the first trimester, all but the pectoral portion of the milk streak atrophies, leaving the nipple bud. The ducts and lobules form from ingrowth of the ectoderm from the nipple surface. Breast development continues in puberty because of an interplay of mammotrophic hormones. By the age of 20, the breast has reached its greatest development. By 40, it begins to undergo atrophic change. © 2008 Springer New York.