Breast Anatomy and Physiology

Breast Anatomy and Physiology

• Mammary glands are paired and located anterior to the pectoralis major and serratus anterior muscles
• They extend vertically from the 2nd to the 6th rib and horizontally from the sternum to the mid-axillary line
• Male and female breasts are similar until puberty
• Female breast tissue enlarges in response to hormones
• The female breast is an accessory reproductive organ with two functions: to produce and store milk for newborns, and to aid in sexual stimulation

Breast Structure

• Breasts are divided into four quadrants by horizontal and vertical imaginary lines intersecting at the nipple
• The upper outer quadrant extends into the axillary area and contains the tail of Spence, where most breast tumors occur

Lymph Nodes

• Present in both male and female breasts
• They drain lymph from the breast to filter out microorganisms and return water and protein to the blood

External Breast Anatomy

• The skin of the breasts is smooth and varies in color depending on the client’s skin tones
• The nipple is located in the center of the breast and contains tiny openings of the lactiferous ducts through which milk passes
• The areola surrounds the nipple with a 1-to 2-cm radius
• The areola contains Montgomery glands that secrete a protective lipid substance during lactation, as well as hair follicles and smooth muscle fibers
• The nipple and areola have darker pigment than the surrounding breast
• Pigment color ranges from dark pink to dark brown, depending on skin tone
• Pigmentation increases with pregnancy but decreases after lactation

Internal Breast Anatomy

• Three tissue types are present: glandular, fibrous, and fatty (adipose)
• Glandular tissue allows for milk production
• 15-20 lobes radiate in a circular fashion from the nipple
• Each lobe contains lobules with secreting alveoli (acini cells)
• Mammary ducts from alveoli converge into a single lactiferous duct that conveys milk to the nipple
• The lactiferous sinus (or ampullae) is a slight enlargement in each duct before it reaches the nipple, where milk can be stored until stimulated
• Fibrous tissue includes Cooper ligaments (suspensory ligaments)
• Fatty (adipose) tissue embeds the glandular tissue
• Subcutaneous and retromammary fat provides most of the breast's substance, determining size and shape
• The functional capability of the breast is related to glandular tissue, not size

Lymph Nodes

• Axillary lymph nodes include:
  • Anterior (pectoral) nodes that drain the anterior chest wall and breasts
  • Posterior (subscapular) nodes that drain the posterior chest wall and part of the arms
  • Lateral (brachial) nodes that drain most of the arms
  • Central (mid-axillary) nodes that receive drainage from anterior, posterior, and lateral lymph nodes
• Infraclavicular or supraclavicular lymph nodes, or deeper nodes within the chest or abdomen can also receive a smaller proportion of lymph

Health Assessment: Subjective Data

• Subjective breast assessment data includes present concerns like lumps or swelling, redness or warmth, dimpling, size or firmness changes, nipple discharge, and pain or tenderness
• COLDSPA is used to further explore symptoms, focusing on character, onset, location, duration, severity, pattern, and associated symptoms
• Pertinent personal history includes history of breast cancer, previous surgeries, breast problems with silicone implants, or trauma to the breast
• Early menses (before age 12) and delayed menopause (after age 52)
• Likelihood of breast cancer is greater for women never giving birth or having their first child after age 30

Health Assessment: Other Considerations

• Hereditary forms of breast cancer constitute only 5-10% of breast cancer cases overall
• Lifestyle and health practices impacting breast health include hormones and antipsychotic agents; galactorrhea; radiation, benzene, or asbestos exposure; high-fat diet; alcohol and smoking; coffee, tea, cola consumption; physical activity; feelings of self-worth; understanding of breast health; and performing breast screenings
• Galactorrhea is a persistent milk secretion, sometimes medication-induced

Screening and Early Detection

• Women aged 40 and older should have a screening mammogram every year
• Biennial mammography screening is recommended for women aged 50-74 years
• Breast self-examination (BSE) is usually performed monthly after the menstrual period for breasts with implants
• Routine BSE includes observation of look and feel, as implants have different texture than natural breast tissue

Types of Breast Cancer

• Ductal carcinoma in situ (DCIS) is noninvasive and confined to the milk duct system
• Invasive (infiltrating) ductal carcinoma (IDC) is the most common type and spreads beyond the ductal system
• Medullary carcinoma occurs in women in their late 40s and 50s
• Invasive (infiltrating) lobular carcinoma (ILC) usually appears as a subtle thickening or change in texture rather than a distinct lump
• Triple-negative carcinoma (TNC) cells in the tumor are negative for progesterone, estrogen, and HER2/neu receptors
• Tubular carcinoma is often found in women over 50 with a 95% 10-year survival rate
• Mucinous carcinoma (colloid) occurs in 1-2% of breast cancers, has a favorable prognosis
• Inflammatory breast carcinoma (IBC) is rare and aggressive; lymph vessels blocked lead to swollen and inflamed breast
• Paget disease of the breast is a rare disease affecting skin of the nipple and areola; often has one or more cancerous tumors

Risk Factors

• Biennial screening mammography for women aged 50-74 years is recommended
• Assess nonmodifiable risks: gender, age, genetics, and race/ethnicity
• Caucasian women have a greater risk for diagnosis, while Black women have a greater risk for dying of breast cancer
• Family history ( genetics and ethnicity) increases likelihood, so does personal history of breast cancer and breast consistency
• Early menstruation (before 12 years of age) or later menopause (older than 55 years) increases chances of breast cancer
• Previous chest radiation before age 40 and Diethylstilbestrol exposure (1940s and 1950s) are additional influencers
• Having no children or giving birth to first child after 30 years of age and usage of recent oral contraceptives increases odds
• Use of menopausal combined hormone replacement therapy (both estrogen and progesterone), no history of breast-feeding, and alcohol consumption are important, as well as excess weight or obesity

Breast Awareness and Self-Exam

• Breast self-assessment and self-examination are vital for detection
• Performing a self-exam can be done three ways: in the shower, lying down, and standing in front of the mirror

Health Assessment: Objective Data Collection

• The purpose of breast assessment is to identify signs of breast disease and initiate early treatment
• Explain the procedure in detail, provide privacy, prepare the client to sit in an upright position, and explain necessity to expose breast to compare for symmetry during inspection

Equipment

• Requires minimal equipment such as:
  • Centimeter ruler
  • Small pillow
  • Gloves
  • Client handout for BSE
  • Slide for specimen

Key Points

• Explain the purpose of the examination and make sure hands are kept warm
• Observe and inspect breast skin, areolas, and nipples
• Palpate breasts and axillary lymph nodes
• Remember that it is important to carefully perform the breast examination with male and female clients

General Routine Screening

• Routine screening includes:
  • Inspect for size and symmetry, color and texture
  • Observe superficial venous pattern
  • Examine areolas and nipples
  • Inspect breasts for retraction or dimpling
  • Palpate skin texture and elasticity
  • Palpate for tenderness and temperature
• Ask the client who performs BSE to demonstrate

Focused Specialty Assessment

• Specialty includes:
  • Asses nipples for discharge
  • Palpate the breasts for masses
  • Palpate mastectomy or lumpectomy site
  • Inspect and palpate axillae

Inspection

• The breasts are first inspected in the sitting position while the client is asked to hold arms in different positions
• The breasts are then palpated while the client assumes a supine position

Inspection and Palpation

• Client should disrobe and sit with arms hanging freely
• Discuss what is being observed to ease client anxiety
• Breasts can be a variety of sizes and are round and pendulous

Breast Inspection and Findings

• Color varies depending on the client’s skin tone
• Texture is smooth, with no edema
• Linear stretch marks may be seen during and after pregnancy
• Redness is associated with breast inflammation, as well as edema

Venous Pattern

• Superficial veins should radiate either horizontally and toward the axilla (transverse) or vertically
• Veins are more prominent during pregnancy

Areolas and Nipples

• Note the color, size, shape, and texture of the areolas of both breasts
• These typically vary from dark pink to dark brown
• Montgomery tubercles are present
• Note the size and direction of the nipples, as well as any dryness, skin lesions, bleeding, or discharge

Normal Nipple Findings

• Nipples are equal bilaterally in size and are in the same location on each breast
• Nipples are usually inverted or evaginated
• There is typically swelling, nodules, or ulceration

Mass Assessment

• Palpation of the breasts includes tenderness and temperature
• Asks the client to lay down or place the arm overhead
• Use the flat pads of three fingers to palpate the breasts, starting from the nipple
• Fibrocystic breast tissue feels ropey, lumpy, is normal, and described as “nodular” or “glandular” breast tissue

Other Assessments

• Inspect for retraction and dimpling
• Check the pectoral muscles and skin
• Bimanual may be used on those with larger breasts
• Mastectomy or lumpectomy includes checking the incision or surrounding site

Abnormal Findings

• Malignant masses or tumors are hard, immobile
• Fibroadenomas are mobile and elastic
• Palipate breast from injury, collection of blood is normal
• Lipomas are collection of fatty tissue

Nipple Conditions

• Nipple discharge should be noted
• Nipple retraction should be examined
• Common causes of nipple discharge include lactation, hypothyroidism, primary tumors