Anatomy, Physiology, and Pathology of the Breast

1. Anatomy, Physiology, andPathology of the Breast Chapter 3 Olive Peart, MS, RT (R)(M) www. opeart.com OP 1

2. Overview The mammary glands Milk-producing organs Effects of scarring or loss Psychological implication OP

3. Milk Line Milk line extends from the armpits in axilla to groin OP

4. Location Upper extent 2 Second or third rib Lower extent 6 Sixth or 7 seventh rib Medial extent Midsternum Lateral extent Midaxillary line (latissimus dorsi muscle) OP

5. Pectoralis Major Muscle • Breast tissue lies on the superficial fascia, which covers the pectoralis major, serratus anterior, and external oblique muscles. • Adipose tissue and connective fascia referred to as the retromammary space separates breast tissue from the pectoral muscle. • The Pectoralis minor muscle is a thin, flat, triangular muscle below the pectoralis major. • The retromammary space is filled with a layer of adipose or fatty tissue. It is seen on the mediolateral oblique projection in mammography imaging, but only on about 20% of the craniocaudal projections.

6. Attachment • Pectoralis major muscle • Retromammary space • Inframammary crease OP

7. Surface Anatomy – The Skin • The skin • Sweat glands • Sebaceous glands • Hair follicles • The skin is thickest at base, thinner toward the nipple OP

8. Surface Anatomy - The Nipple & Areola Nipple - Center point of breast 15-20 orifices or collecting ducts Can be flattened or inverted normally Areola - Circular darkened area around nipple Morgagni tubercles (opening of the ducts of the Montgomery glands) OP

9. Shape and Size of the Breast Variation in shape and size determined by Age Menstrual cycle Lactation Hormonal secretions OP

10. Location Terminology Four-quadrant • Upper-outer quadrant (UOQ)—tail of Spence (axillary tail) • Upper-inner quadrant (UIQ) • Lower-outer quadrant (LOQ) • Lower-inner quadrant (LIQ) OP

11. Location Terminology Clock Face • 12 o’clock, 3 o’clock, 6 o’clock, 9 o’clock etc. • Note: 4 o’clock on the right breast is the LIQ but will represent the LOQ on the left OP

12. Location Terminology Region Method • Posterior • Middle • Anterior • Subareola OP

13. Deep Anatomy • Adipose /fatty tissue—between lobes • Glandular tissue—within lobes • Lymphatic vessels • Blood vessels OP

14. Lobes Gray area indicates 1 lobe • Average female breast has 15-20 lobes • Each lobule can have 10-100 terminal ductules OP

15. Breast Ductal System Nipple orifice Lactiferous/connecting duct Ampulla—pouch-like sac Segmental/mammary ducts Lobule OP

16. The Lobule or TDLU Extralobular terminal duct (ETD) Elastic tissue, lined by columnar cells Intralobular terminal duct (ITD) Cuboidal cells Alveolar gland Acinus—milk-producing OP

17. Lining of Ducts and Alveoli Two layer epithelium of cells Innermost layer—myoepithelial cells Basement membrane Connective tissue OP

18. Multilayered Epithelium Layer Superficial (luminal) A cells Basal B cells (chief cells) Myoepithelial cells— contraction helps propel milk OP

19. Arterial Supply to the Breast • Arterial supply from branches of • Axillary artery • Lateral thoracic • Acromiothoracic • Internal thoracic • 2 Second – 6 sixth intercostal arteries OP

20. Venous Drainage Veins are larger than arteries and more peripherally located Internal thoracic vein Intercostal veins OP

21. Lymph Node Size Less than 2 cm Shape Kidney appearance Significance Route a malignant disease leaves the breast OP

22. Lateral and Medial Lymphatic Drainage Lateral breast drains to pectoral group then to axillary nodes Medial breast drains to internal mammary lymph nodes, parasternal nodes, or the other breast OP

23. Superficial Lymph Drainage • Lymph drains from the breast to: • Pectoral nodes • Subclavian nodes OP

24. The Axillary Lymph Nodes • Anterior group—lying deep below the pectoralis major muscle and along the lower border of the pectoralis minor and sometimes referred to as the pectoral nodes • Posterior group—lying along the subscapular vessels and sometimes referred to as the subscapular nodes • Lateral group—lying along the axillary vein • Central group—lying in the axillary tissues; this is the most palpable group • Apical group—lying above the pectoralis minor at the apex of the axilla and behind the clavicle

25. Nervous Supply The breast and the skin over it are supplied with sensory and sympathetic nerves by branches of the cervical plexus and by thoracic branches from the brachial plexus. The sympathetic and parasympathetic divisions of the ANS control of most of the body’s internal organs. The breast is also innervated by the anterior and lateral cutaneous branches of the second through sixth intercostal nerves OP

26. Breast Tissue Composition • The breast is made up of a varying mixture of adipose or fatty tissues, glandular or secretory components, lymphatic vessels, and blood vessels. • The fibrous and glandular tissues within the breast are generally described as fibroglandular densities. • In general, the amount of fatty and glandular tissues varies with age. • Most typically, glandular tissue predominates in younger women, whereas fatty tissue predominates in older women.

27. Cooper’s Ligaments • Fibrous bands in the upper parts of the breast • Attach the breast to the skin • Also called suspensory ligament OP

28. Factors Affecting Tissue Composition Hormones Menarche Hormonal fluctuation (Normal or synthetic) Pregnancy Lactation Involution Perimenopause & Menopause Weight gain/loss OP

29. Menarche to Perimenopause • Young breast • No lobules • Small ducts within fibrous tissue • Menarche • First menses – breast is developed • Perimenopause • Declining hormone levels • Fluctuating ovulation cycles • Irregular or heavy menstrual cycles OP

30. Menopause and Involution Menopause Official menopause No period for a year Occurs between age 45 and 54 Involution Occurrence increases after menopause Atrophy of glandular tissue Loss of supportive and connective tissue to fat OP

31. Fatty versus Glandular Tissue Fatty More radiolucent Dense Glandular Less radiolucent Centrally located Extending laterally to axilla Fatty Dense OP

32. Hormones Acting on the Breasts Several hormones are responsible for the rapid changes that begin to take place. Prolactin, estrogen, and progesterone are produced by the female reproductive system Adrenal steroids by the adrenal glands - metabolism Insulin by cells in the pancreas – glucose absorption Growth hormone by the pituitary – growth effects Thyroid hormone by the thyroid glands – cellular activity/metabolism Estrogen—growth of ducts Progesterone—lobular development Prolactin—lobular development during pregnancy OP

33. Most Important Hormones • Estrogen • Ductal proliferation • Progesterone • Lobular proliferation and growth OP

34. Hormone Changes and the Breast Hormone Replacement Therapy (HRT) is used by women who still have a uterus. Progestin is added to estrogen to prevent the overgrowth (or hyperplasia) of cells in the lining of the uterus. This overgrowth can lead to uterine cancer therefore, women without a hysterectomy are given estrogen plus progestin therapy. Women who have had their uterus removed cannot get endometrial cancer; therefore, these women can take estrogen alone. This is called estrogen therapy (ET) or estrogen replacement therapy (ERT). Hormone Therapy (HR) can results in: Increased glandularity—sometimes spotty Increased size and sensitivity Increased density and glandular tissue Increased nodularity, fibroadenomas and development of breast cyst Inhibition of the involution process OP

35. Effects of HT • Positive • Relives symptoms of perimenopause • Hot flushes • Sleep disturbance • Insomnia • Fatigue • Osteoporosis • Negative • Breast/uterine cancer • Asthma • Dementia • Heart attacks • Strokes • Blood clots OP

36. Lactation Effect on Breast Tissue Enlarged, firmer breast Darkened areola Enlarged, erect nipple Lobules increase in size Overall glandularity reduces the accuracy of the mammogram Increase radiation dose to the patient Patient should nurse just prior to mammogram OP

37. Effect of Parity on Breast Tissue Parity is the terminology used if a woman carries a pregnancy to a point of viability (20 weeks of gestation) regardless of the outcome. Multiparity is regarded as having borne more than one child, and primaparity as having delivered a child of at least 500 g (or 29 weeks’ gestation) regardless of viability. A multiparous woman is generally considered to have a slightly lower risk for breast cancer than a nulliparous woman or one who has the first child after age 30 years. Multipartiy is associated with breasts that involutes earlier The nulliparous woman is described as one who has never given birth to a viable offspring Nulliparous breasts involutes slower than a multiparous breast OP

38. Male Breast • The adult male breast is similar to a preadolescent girl. • There may be a few branching ducts lined by flattened cells and surrounded by connective tissues, most often located behind the nipple and areola. • Enlargement of the male breast due to growth of the ducts and supporting tissues is known as gynecomastia (Fig B) • About 40% of adolescent boys will experience a temporary breast enlargement in response to hormones being secreted by the testes, but this response typically will disappear in 1 to 2 years.

39. Male Breast Cancer • Breast cancer in men, like breast cancer in women, will have similar signs and symptoms • Risk Factors • Increasing age increases the risk for breast cancer in males. • Heredity of the breast cancer gene • Radiation exposure • Hormones • Klinefelter’s syndrome

40. Diagnosis, Treatment, and Prognosis • The same procedures can be used to diagnose both male and female breast cancer. • All types of cancers seen in women can also occur in men, although lobular carcinomas are rare because lobules are normally absent from the male breast • Distant metastasis in males occurs in patterns similar to that of females and will most often affect the bone, lungs, lymph nodes, liver, and brain • The prognosis for men with breast cancer is similar to females with the same stage and type of cancer. However, because the male breast is typically much smaller than the female, the cancer very rapidly reaches the nipple, the skin, or muscles under the breast.