Clinical Presentation

Chapter 23 - The Breast

Susan C. Lester MD, PhD

The Female Breast

Normal

The class Mammalia is remarkable for the evolution of modified skin appendages that provide complete nourishment and immunologic protection for the young. In humans, paired

mammary glands rest on the pectoralis muscle on the upper chest wall. The breast is composed of specialized epithelium and stroma that give rise to both benign and malignant lesions

specific to the organ ( Fig. 23-1 ).

Six to ten major ductal systems originate at the nipple. The keratinizing squamous epithelium of the overlying skin continues into the ducts and then abruptly changes to a double-layered

cuboidal epithelium. A small keratin plug is often found at the duct orifice. The surrounding areolar skin is pigmented and supported by smooth muscle.

Successive branching of the large ducts eventually leads to the terminal duct lobular unit (TDLU). In the adult woman, the terminal duct branches into a grapelike cluster of small acini to

form a lobule ( Fig. 23-1 and Fig. 23-2B ). Each ductal system typically occupies over a quarter of the breast, and the systems extensively overlap each other. In some women, ducts extend

into the subcutaneous tissue of the chest wall and into the axilla.

Figure 23-1Normal breast anatomy and anatomical location of common breast lesions.

Figure 23-2Lifecycle changes. A, Mammograms in young women are typically "dense" or white in appearance. In this setting, mass-forming lesions or calcifications can be difficult to

detect. (Courtesy of Dr. Darrell Smith, Brigham and Women's Hospital, Boston, MA.) B, The density of a young woman's breast is due to the predominance of fibrous interlobular stroma

and the paucity of adipose tissue (normally radiolucent or black). Prior to pregnancy, the terminal duct lobular units (TDLUs) are small and are invested by loose cellular intralobular

stroma. Larger ducts interconnect the TDLUs. C, During pregnancy, branching of terminal ducts results in more numerous TDLUs, and the number of acini per TDLU increases. Luminal

cells within TDLUs (but not the large duct system) undergo lactational change in preparation for milk production. D, With increasing age, the TDLUs decrease in size and number, and the

interlobular stroma is replaced by adipose tissue. An older woman's breast typically consists of small ducts and atrophic lobules in adipose tissue. E, Mammograms become more

radiolucent (darker) with age owing to the increase in adipose tissue. Radio-dense mass-forming lesions, and calcifications become easier to detect. (Courtesy of Dr. Darrell Smith,

Brigham and Women's Hospital, Boston, MA.)

Figure 23-3Common clinical presentations of breast disease. Over a 10-year period, 372 women over the age of 40 made 539 visits to a health maintenance organization for the listed

breast symptoms.[9] Some women had more than one symptom and/or made more than one visit. In 10% of cases, the visit led to the performance of a biopsy.

TABLE 23-1-- Characteristics of Breast Carcinomas by Clinical Presentation

Clinical Presentation

Date: 2016-04-22; view: 668