HUMAN ANATOMY of Dr KB Ashok, MBBS, AIIMS, New Delhi

THE BREAST

Introduction/General Information A. Embryologically: belong to integument B. Functionally: part of reproductive system 1. Respond to sexual stimulation 2. Feed babies

C. Modified apocrine sweat glands Breast, continued … C. Modified apocrine sweat glands - apex of cell becomes part of secretion and breaks off D. Present in males and females

A. Position and Attachment 1. Lateral aspect of pectoral region 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

Breast Anatomy

6. Fixed to skin & underlying fascia by fibrous C.T. bands 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

Cooper’s Suspensory Ligaments

7. Left breast is usually slightly larger Position & attachment, continued … 7. Left breast is usually slightly larger 8. Base is circular, either flattened or concave 9. Separated from pectoralis major muscle by fascia, retro-mammary space

Retromammary Space Retromammary Space

1. Outer surface convex, skin covered 2. Nipple: 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

d. Thin skinned region lacking hair, sweat glands Structure, continued … c. Surrounded by areola: pigmented ring of skin d. Thin skinned region lacking hair, sweat glands e. Contains areolar glands

a. Circular and radial smooth muscle fibers Structure, continued … 3. Areola: contains dark pigment that intensifies with pregnancy a. Circular and radial smooth muscle fibers b. Cause nipple erection

Areola

a. Each lobe has one lactiferous duct 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

Lobes and Lobules

a. Form ampullae (collection sites of lactiferous sinuses) 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

Excretory (lactiferous) ducts

a. Changes with hormonal signals b. Onset of menstruation 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)

b. Passes under axillary fascia 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

a. Determines form & size of breast Structure, continued … 8. Fatty Tissue: surrounds surface, fills spaces between lobes a. Determines form & size of breast b. No fatty deposit under nipple & areola

Breast: Fatty Tissue

1. Arteries: derived from thoracic branches of three pairs of arteries 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

c. Intercostal arteries: 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

External mammary (thoracic) a. Internal mammary (thoracic) a. Subclavian a. Axillary a. External mammary (thoracic) a. Internal mammary (thoracic) a. Arterial Supply to the Breast

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

a. anterior & lateral cutaneous nerves of thorax Breast Anatomy, con’t… 3. Innervations: 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

Lateral pectoral nodes Parasternal nodes Subclavian nodes Axillary nodes Lateral pectoral nodes Parasternal nodes Lymph Nodes of the Breast

d. NOTE: axillary nodes also drain lymph from arm 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

1. Inverted nipple: congenital or due to cancer 2. Ectopic nipple: 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

a. breast development of male in areolar region 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

a. Menstruation – tenderness from fluid engorgement 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

C. General symptoms & signs 1. Nipple discharge 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

5. Retraction sign: “dimpling” involving skin, nipple or areola 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 May grow into bone

a. Cysts = fluctuant; compressible 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

b. Other causes 1) testicular or pituitary tumor 2) cirrhosis Hypertrophy, continued … b. Other causes 1) testicular or pituitary tumor 2) cirrhosis 3) hypogonadism = not enough testosterone 4) estrogen administration for prostate cancer

4. Tumors & cysts a. Fibroadenoma = most common benign breast tumor Benign Conditions, continued 4. Tumors & cysts a. Fibroadenoma = most common benign breast tumor

2. May be aspirated if large Tumors and Cysts, con’t… b. Breast Cyst 1. Benign 2. May be aspirated if large

c. Fibrocystic breast changes 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

d. Intraductal papilloma 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

Progression to Breast Cancer

a. Slowly growing, painless mass Carcinoma of breast, continued … 4. Physical signs: a. Slowly growing, painless mass b. May demonstrate retracted nipple c. May be bleeding from nipple d. May be distorted areola, or breast contour e. Skin dimpling in more advanced stages with retraction of Cooper’s ligaments

f. Attachment of mass g. Edema of skin Physical signs, continued … f. Attachment of mass g. Edema of skin 1)with “orange skin” appearance (peau d’orange) 2) due to blocked lymphatics h. Enlarged axillary or deep cervical lymph nodes

5. Common sites for metastasis Breast Cancer, contd. 5. Common sites for metastasis a. Lungs & pleura b. Skeleton system (skull, vertebral column, pelvis) c. Liver 6. Atypical carcinomas a. Inflammatory carcinoma (hormonal, chemotherapy) b. Paget’s disease of the breast

Quick Overview

PROSTATE GLAND

Introduction/General Information Attached inferiorly to urinary bladder by ligaments Posterior to pubic symphysis Surrounds superior portion of urethra Anterior to rectum (palpation, ultrasound) Conical shape

1. 4 cm trans x 2 cm A/P x 3 cm Sup/Inf G. Lightly encapsulated Introduction, Prostate Gland, continued … F. Walnut sized 1. 4 cm trans x 2 cm A/P x 3 cm Sup/Inf G. Lightly encapsulated 1. Fibrous connective tissue 2. Smooth muscle 3. Capsule extends into lobes

Prostate Gland, Mid-sagittal Section II. Prostate Gland: Detailed Anatomy A. Largest male accessory gland B. Located in subperitoneal compartment (between pelvic diaphragm & peritoneum) Prostate Gland, Mid-sagittal Section

Prostate Gland: Detailed Anatomy C. Enclosed in fascial sheath(prostatic sheath) 1. Inferiorly, sheath is continuous with superior fascia of urogenital diaphragm 2. Posteriorly, sheath forms part of retrovesical septum

1. Fibrous portion contacts gland Prostate Gland: Detailed Anatomy D. Double Capsule 1. Fibrous portion contacts gland 2. External capsule formed by pelvic fascia 3. Venous plexus lies between

Male Reproductive System, Posterior View

E. Conical shape with base (sup), apex (inf), four surfaces Detailed Anatomy, continued … E. Conical shape with base (sup), apex (inf), four surfaces 1. Surfaces: posterior, anterior, right & left inferolateral 2. Base (vesicular surface): superior a. Attached to neck of urinary bladder b. Prostatic urethra enters middle of base close to anterior surface

Prostate Anatomy Prostatic Urethra

a. Rests on superior fascia of urogenital diaphragm muscle Detailed Anatomy, contined … 3. Apex: inferior a. Rests on superior fascia of urogenital diaphragm muscle b. Associated with sphincter urethrae c. Contacts medial margins of levator ani muscles

5. Anterior surface: narrow, convex 6. Inferiorolateral surfaces Detailed Anatomy, continued … 4. Posterior surface: triangular, flat 5. Anterior surface: narrow, convex 6. Inferiorolateral surfaces a. Meet with anterior surface b. Rest on levator ani fascia above urogenital diaphragm

1. Divisions are arbitrary, indistinct 2. Usually divided into Detailed Anatomy, continued … F. Lobes of the Prostate 1. Divisions are arbitrary, indistinct 2. Usually divided into a. two lateral lobes b. one median lobe c. anterior and posterior lobes

Lobes of the Prostate, continued … 3. Median lobe a. Lies posterior and superior to prostatic utricle and ejaculatory ducts b. May project into urinary bladder c. Utricle lies within lobe 1. Vestigial remains of uterine homolog 2. Sometimes called “uterus masculinis”

a. Comprise the greatest mass of the gland Lobes of the Prostate, continued … 4. Lateral lobes a. Comprise the greatest mass of the gland b. Contain most secretory tissue c. Are continuous posteriorly 5. Glandular tissue with varying amounts of fibrous tissue

Lobes of the Prostate, continued … Prostate Gland in situ

1. Arteries derived from: Detailed Anatomy, continued … G. Blood & lymph 1. Arteries derived from: a. Internal pudendal artery b. Inferior vesical artery c. Middle rectal artery

a. Form venous plexus b. Drain into internal iliac veins Blood & Lymph, continued … 2. Veins a. Form venous plexus b. Drain into internal iliac veins c. Communicate with vesical & vertebral venous plexuses

a. Most terminate in internal iliac & sacral nodes (unable to palpate) Blood & Lymph, continued … 3. Lymphatics a. Most terminate in internal iliac & sacral nodes (unable to palpate) b. From posterior: to external iliac nodes (unable to palpate)

1. 30 - 50 different glandular elements a. Serous glands Detailed Anatomy, continued … Glandular tissue 1. 30 - 50 different glandular elements a. Serous glands b. 20 - 30 ducts empty into prostatic urethra 2. Most are posterior & lateral to urethra

a. Thin, milky, alkaline (looks like skim milk) Blood & Lymph, continued … 3. Prostatic secretions a. Thin, milky, alkaline (looks like skim milk) b. Discharged at ejaculation c. Make up ~ 1/3 of semen

Prostate size changes 1. Small at birth 2. Enlarges at puberty Detailed Anatomy, continued … Prostate size changes 1. Small at birth 2. Enlarges at puberty 3. Maximum at about 13 4. Progressive enlargement after 40 5. Sometimes: undergoes atrophy

III. Pathology 1. Affects ~90% of men >50 A. Benign prostatic hypertrophy (BPH): 1. Affects ~90% of men >50

a. Nocturia 2. Common cause of urethral obstruction causes: b. Dysuria BPH, continued … 2. Common cause of urethral obstruction causes: a. Nocturia b. Dysuria c. Urgency d. Back-pressure effects e. Complete obstruction can occur

B. Prostate cancer 1. Most common cancer in males Pathology, continued … B. Prostate cancer 1. Most common cancer in males

2. Metastasizes via blood (haematogenous)or lymph (lymphogenous) Pathology, continued … 2. Metastasizes via blood (haematogenous)or lymph (lymphogenous) 3. Common sites: vertebrae, pelvis a. Via venous plexus surrounding prostate b. Bone or direct metastasis most common

Prostate Cancer: Routes of Metastasis

Prostatitis (accompanied by cystitis) 1. Inflammation of gland Pathology, continued … Prostatitis (accompanied by cystitis) 1. Inflammation of gland 2. Gland enlarges, becomes tender 3. Causes: gonorrhea? Other UTI’s? STD’s? 4. May require antibiotics, massage 5. Symptoms: chills, painful urination, back pain

Prostatic concretions (corpora amylacea [starch bodies]) Pathology, continued … Prostatic concretions (corpora amylacea [starch bodies]) 1. Small spherical or ellipsoid bodies 2. Number increases with age 3. May become calcified as male ages 4. May simulate carcinoma

Digital Rectal Exam

E. Rarely, prostatic abscesses develop Pathology, continued … E. Rarely, prostatic abscesses develop 1. Frequently caused by gonorrhea 2. May rupture through to rectum, bladder, perineum 3. Other causes: a. Urethritis b. Epididymitis

Quick Overview