Chapter 18: Breasts, Axillae, and Regional Lymphatics

Breasts, Axillae, and Regional Lymphatics establishes a thorough understanding of internal mammary anatomy, outlining the roles of glandular tissue, lactiferous ducts, protective adipose tissue, and Cooper's suspensory ligaments, while specifically highlighting the clinical significance of the four breast quadrants, the axillary tail of Spence, and the extensive network of axillary lymph nodes (central, pectoral, subscapular, and lateral). The text extensively details developmental milestones across the lifespan, evaluating adolescent development and puberty onset through Tanner staging (thelarche), pregnancy-related maternal adaptations such as colostrum production and lactation, and the atrophic glandular changes associated with menopause and aging. A significant focus is placed on breast cancer risk assessment, emphasizing the importance of genetics (such as BRCA1, BRCA2, and PALB2 mutations), structural racial disparities in mortality, and modifiable lifestyle influences like alcohol consumption, obesity, and postmenopausal hormone replacement therapy. For clinical practice, the chapter outlines the systematic collection of subjective data concerning mastalgia, masses, galactorrhea, and trauma, which is paired with objective physical assessment techniques. Students are guided through inspection maneuvers to identify skin retraction signs (such as dimpling and peau d'orange) and bimanual palpation methods utilizing the vertical strip pattern to locate and document the specific characteristics of clinical masses. Furthermore, the material equips learners to distinguish between benign fibrocystic breast disease, fibroadenomas, and invasive breast cancers using the BREAST acronym for advanced warning signs. The chapter concludes by exploring abnormal findings, including nipple discharge pathologies like Paget disease and mammary duct ectasia, lactation complications such as mastitis and plugged ducts, and male breast abnormalities like gynecomastia, ultimately reinforcing patient-centered care strategies for breast self-examination and evidence-based mammography screening.