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THE BREAST. http://hastaneciyiz. blogspot .com. Medical ppt. I. Introduction/General Information A. Embryologically: belong to integument B. Functionally: part of reproductive system 1. Respond to sexual stimulation 2. Feed babies. Breast, continued …
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THE BREAST http://hastaneciyiz.blogspot.com Medicalppt
I. Introduction/General Information A. Embryologically: belong to integument B. Functionally: part of reproductive system 1. Respond to sexual stimulation 2. Feed babies
Breast, continued … • C. Modified apocrine sweat glands • - apex of cell becomes part of secretion and breaks off • D. Present in males and females
II. Anatomy • A. Position and Attachment • 1. Lateral aspect of pectoral region • 2. Located between ribs 3 and 6/7 • 3. Extend form sternum to axilla • 4. Surrounded by superficial fascia • 5. Rest on deep fascia
Position & attachment, continued …. 6. Fixed to skin & underlying fascia by fibrous C.T. bands a. Cooper’s (Suspensory) Ligaments b. Ligaments may retract when breast tumors are present
Position & attachment, continued … 6. Left breast is usually slightly larger 7. Base is circular, either flattened or concave 8. Separated from pectoralis major muscle by fascia, retromammary space
Retromammary Space Retromammary Space
Anatomy, continued … • B. Structure • 1. Outer surface convex, skin covered • 2. Nipple: • a. At fourth intercostal space • b. Small conical/cylindrical prominence below center
Nipple location 4th intercostal space
Structure, continued … • c. Surrounded by areola: pigmented ring of skin • d. Thin skinned region lacking hair, sweat glands • e. Contains areolar glands
Structure, continued … 3. Areola: contains dark pigment that intensifies with pregnancy a. Circular and radial smooth muscle fibers b. Cause nipple erection
Structure, continued … 4. Each breast consists of ~ 20 lobes of secretory tissue a. Each lobe has one lactiferous duct b. Lobes (and ducts) arranged radially c. Embedded in connective tissue & adipose of superficial fascia d. Lobes composed of lobules e. Lobules comprise alveoli
Structure, continued … 5. Excretory (lactiferous) ducts converge toward areola a. Form ampullae (collection sites of lactiferous sinuses) b. Ducts become contracted at base of nipple
Structure, continued … 6. Secretory epithelium a. Changes with hormonal signals b. Onset of menstruation c. Pregnancy (glands begin to enlarge at 2nd month) d. After birth, 1st secretion is colostrom (contain antibodies)
Structure, continued … 7. “Tail of Spence” = axillary tail a.prolongation of upper, outer quadrant in axillary direction b. Passes under axillary fascia c. May be mistaken for axillary lymph nodes
“Tail of Spence” Axillary Tail
Structure, continued … 8. Fatty Tissue: surrounds surface, fills spaces between lobes a. Determines form & size of breast b. No fatty deposit under nipple & areola
Structure, continued … • Vessels & nerves • 1. Arteries: derived from thoracic branches of three pairs of arteries • a. Axillary arteries • 1) continuous with subclavian a. 2) gives rise to external mammary ( = lateral thoracic) artery
Vessels & Nerves, continued … • b. Internal mammary (thoracic) arteries 1) first descending branch of subclavian artery 2) supply intercostal spaces & breast • 3) used for coronary bypass surgery • c. Intercostal arteries: • 1) numerous branches from internal & external mammary arteries • 2) supply intercostal spaces & breast
Arterial Supply to the Breast Subclavian a. Internal mammary (thoracic) a. Axillary a. External mammary (thoracic) a.
Vessels & Nerves, continued … • Veins: a. form a ring around the base of the nipple (“circulus venosus”) • b. Large veins pass from circulus venosus to circumference of mammary gland, then to • c. External mammary v to axillary v or • d. Internal mammary v to subclavian v
Veins draining the Breast Subclavian vein External mammary vein
Breast Anatomy, con’t… • 3. Innervation: derived from: • a. anterior & lateral cutaneous nerves of thorax • b. spinal segments T3 – T6
Structure, continued … 4. Lymphatics: clinically significant! a. Glandular lymphatics drain into anterior axillary (pectoral) nodes central axillary nodes apical nodes deep cervical nodes subclavicular (subclavian) nodes b. Medial quadrants drain into parasternal nodes
Lymph Nodes of the Breast Subclavian nodes Axillary nodes Parasternal nodes Lateral pectoral nodes
Lymphatics, continued … c. Superficial regions of skin, areola, nipples: -form large channels & drain into pectoral nodes d. NOTE: axillary nodes also drain lymph from arm
Lymph Nodes and Lymph Drainage Axillary Nodes
Routes of Metastasis • From medial lymphatics to parasternal nodes • Then to mediastinal nodes • Across the sternum in lymphatics to opposite side via cross-mammary pathways • Then to contralateral breast • From subdiaphragmatic lymphatics to nodes in abdomen • Then to liver, ovaries, peritoneum
Major Routes of Metastasis Channels to Contralateral Breast Axillary Lymph Channels Subdiaphragmatic Lymph Channels
Structure, continued … • Anomalies • 1. Inverted nipple: congenital or due to cancer • 2. Ectopic nipple: • a. “polythelia” or “hyperthelia” • b. additional nipples along milk line • 3. Amastia • 4. Micromastia
Anomalies, continued … 5. Macromastia 6. Gynecomastia a. breast development of male in areolar region b. noted in males who smoke marijuana at puberty
III. Diseases of the Breast • A. Most are readily detectable • B. Etiology unknown, influencing factors • 1. Sex • 2. Heredity
Diseases of the breast, continued … 3. Endocrine influence a. Menstruation – tenderness from fluid engorgement b. Post-menopause 1) decrease of fibro-cystic disease 2) increase in cancer c. Pregnancy
Diseases of the Breast, continued … C. General symptoms & signs 1. Nipple discharge a. always significant if not pregnant. b. May be due to benign pituitary tumor. 2. Local pain, tenderness 3. Duration of lesion 4. Size, rate of growth
Symptoms & Signs, continued … 5. Retraction sign: “dimpling” involving skin, nipple or areola 6. Mobility of mass a. Benign = movable 1) not attached 2) not invasive b. Malignant = attached 1)May grow into bone
Symptoms & Signs, continued … 7. Consistency of mass a. Cysts = fluctuant; compressible b. Fibroadenoma = rubbery c. Carcinoma = firm, hard (like gravel) 8. Axillary area lymph node enlargement
D. Benign breast conditions • 1. Infection = usually during or after lactation • a. Recurrent, subareolar abscess • b. TB of the breast • 2. Trauma = contusion • 3. Hypertrophy = seen in either sex at adolescence • a. Gynecomastia = in males
Hypertrophy, continued … b.Other causes 1) testicular or pituitary tumor 2) cirrhosis 3) hypogonadism = not enough testosterone 4) estrogen administration for prostate cancer
Benign Conditions, continued 4. Tumors & cysts a. Fibroadenoma = most common benign breast tumor
Tumors and Cysts, con’t… b. Breast Cyst 1. Benign 2. May be aspirated if large
Benign conditions, continued … c. Fibrocystic breast changes 1) 20%+ of premenopausal women 2) discomfort, cysts 3) treatment rarely required 4) More likely to not detect a developing cancer
Tumors & cysts, continued …. • d. Intraductal papilloma • - may produce “chocolate” or bloody discharge from nipple • e. Lipoma: common • - fatty tumors
E. Carcinoma of the breast • Most common malignant tumor among women • 1/8 of women will develop breast cancer • a. 1/6 in Orange County • b. 1/5 in San Francisco • 3. Generally no discomfort