Chapter 21 (from binder)

Breast

Modified swear gland in the superficial fascia of anterior chest wall

Axillary/ tail of spence

armpit area

Areola

circular area of darker pigmentation seen around the nipple

Breast layers

1. subcutaneous, 2. mammary (gandular), 3. retromammary

Subcutaneous

lies just beneath the skin extending to the mammary layer (thin layer), consist primarily of fatty tissue

Mammary layer (functional portion of the breast)

made up of 15-20 lobes, terminal ductal lobular unit (TDUL), Acini, lactiferous duct, stroma, cooper’s ligaments

terminal ductal lobular unit (TDUL)

made up of acini and terminal ducts

Acini

milk-producing glands

lactiferous duct

carry milk from acini to the nipple

stroma

the fatty and connective tissue interspersed between lobes

cooper’s ligaments

provide support to the breast, forms a fibrous ‘skeleton’. connect to the fascia around the ducts and glands and extend out to the skin

Retromammary layer

Function: Allows breast to move along the chest wall

Fatty tissue, coopers ligaments

Muscular layer

consists of pectoralis major and pectoralis minor muscles

Chest wall

ribs & intercostal muscles

Sonographic appearance:

Boundaries of the breast: skin line, nipple, and retromammary layer

strong, bright echo reflections

Sonographic appearance:

Subcutaneous fat

Hypoechoic echotexture *fat in the breast looks darker*

Sonographic appearance:

cooper’s ligaments and connective tissue

Echogenic, dispersed in in a linear pattern, compression of the breast often enhances the ability to visualize them

Sonographic appearance:

mammary-grandular layer

Amount of fatty tissue dictates the amount of intensity reflected from the breast parenchyma

Fatty tissue- hypoechoic

Connective tissue- echogenic or hyperechoic

Sonographic appearance:

retormammary layer

simular to subcutaneous fat

Boundary echoes resemble skin reflections

Sonographic appearance:

Pectoral muscles

low-level echo areas posterior to the retromammary layer

Sonographic appearance:

Ribs

hperechoic rounded structures

dense posterior shadowing

Parenchymal pattern

size and shape of the breast vary remarkably from woman to woman

involutional changes affect the appearance & pattern of the parenchyma

Involution:

hallmarked in breast imaging by the remodeling process that causes glandular tissue to be slowly replaced by fatty tissue

Young Parenchymal pattern

fibrous tissue elements

dense echogenic pattern

pregnant or lactating Parenchymal pattern

larger and denser glandular portions (due to milk production)

less echogenic inferfaces

Mature Parenchymal pattern

fatty tissue begins to replace glandular tissue (involution)

postmenopausal Parenchymal pattern

ducts atrophy

less fibrous tissue

all 3 layers of the breast appear hypoechoic

Vascular supply

Main arterial supply to breast

internal mammary artery

lateral thoracic artery

Vascular supply

Central and medial portions

supplied by the anterior performing branches of the internal mammary artery

Vascular supply

upper outer quadrant

supplied by the lateral thoracic artery

Vascular supply

secondary blood supply source

intercostal (inferior margins) and thoracodorsal (superior regions) arteries contribute in lesser ways to the blood supply

Vascular supply

Venous drainage provided mainly by

superficial veins

Lymphatic system

moves from the intramammary nodes and deep nodes centrally toward the axillary lymph node chains

____ of lymph is eliminated by the internal chain

3%

_____ of lymph is removed by the axillary chain

97%

Axillary lymph node dissection

vital in the staging and management of breast cancer

Axillary lymph nodes classified based upon their relationship to the pectoralis major muscle

level I

level II (rotter’s nodes)

level III

The male breast

retains some ductal elements behind the nipple

gynecomastia: breast ductal elements hypertrophy

Breast function

Fluid transport and milk production

Puberty-

Estrogen:

promotes growth in ductal system

Pregnancy/lactation-

Prolactin:

simulates the acini to produce and excrete milk

Menopause-

Involution

glandular tissue replaced by fatty tissue

Breast cancer screening:

Primary purpose

detection and diagnosis of breast cancer in its easiest and most curable stage

Breast cancer screening:

Ultrasound & MRI

are used to provide additional characterization and further interrogation of breast lesions that are not well visualized by mammography

screening mammograms

women aged 40 and over who are asymptomatic

diagnostic mammograms

performed on patients who represent with any clinical signs of possible breast cancer

BI-RADS

Breast Image Report and Data Systems

BI-RADS:

Category 1

normal (routine followup)

BI-RADS:

Category 2

benign (routine followup)

BI-RADS:

Category 3

probably (short-term followup)

BI-RADS:

Category 4

suspicious (biopsy considered)

BI-RADS:

Category 5

malignant (lumpectomy, mastectomy)

Breast Ultrasound:

2 approaches

a targeted examination

whole breast examination

image optimization

image tissue from skin through chest wall equally

Lesion location and annotation methods

clock face, quadrant, distance from nipple, 123…ABC method

First ring (zone 1)

circle one-third of the breast tissue just outside the nipple

Second ring (zone 2)

is two thirds of the breast surface

final ring (zone 3)

is to the breast periphery

A =

Lesions located close to the nipple; more superficial

B =

Lesions in the middle of the breast

C =

Lesions located at the outer margin of the breast

Three dimensional measurements methods

1. sagittal/transvers

2.radial/antiradial

ultrasound pitfalls

pseudomass, infiltrative pattern (ill-defined breast layers), large&fatty breast

sagittal and transvers

scan planes correspond with conventional sagittal and transverse on the body

radial and antiradial

scan plans correlate with the direction of the ductal systems of the breast

Radial

parallel to ducts

Antiradial

Transverse or perpendicular to ducts

Sonographic Characteristics of Breast Lesions:

Simple Cyst

smooth walls and inner margins

anechoic

posterior acoustic enhancement

Sonographic Characteristics of Breast Lesions:

Complicated (complex) Cyst

wall thickening or irregularities

septations

internal echoes

CYST NEVER CONTAIN BLOOD FLOW!

CYST NEVER CONTAIN BLOOD FLOW!

Sonographic Characteristics of a Solid Mass: Margins

Benign

smooth, rounded, well-defined

Sonographic Characteristics of a Solid Mass: Margins

malignant

indistinct, fuzzy, speculated

Sonographic Characteristics of a Solid Mass: Margins

spiculation

when a tumor grows through the tissue via finger-like extensions

Sonographic Characteristics of a Solid Mass: Margins

Fremitus

a palpable tremor or vibration of the chest wall.

• used to identify and confirm the margins of a mass

• use power doppler- have the patient hum

Sonographic Characteristics of a Solid Mass: Shape

Benign

rounded or oval, large lobulations

Sonographic Characteristics of a Solid Mass: Shape

Malignant

sharp, angular, microlobulations

Sonographic Characteristics of a Solid Mass: Orientation

Malignant

taller-than-wide; radial growth suspicious for intraductal lesions

Sonographic Characteristics of a Solid Mass: internal echo pattern

benign

isoechoic, hyperchoic

Sonographic Characteristics of a Solid Mass: internal echo pattern

Malignant

hypoechoic, weak internal echoes, clustered microcalcifications

Sonographic Characteristics of a Solid Mass: Attenuation effects

Benign

posterior enhancement

Sonographic Characteristics of a Solid Mass: Attenuation effects

Malignant

strongly attenuating (dense)

Sonographic Characteristics of a Solid Mass: disruption of breast architecture

Benign

grows within tissue causing compression of the tissue adjacent to the mass

Sonographic Characteristics of a Solid Mass: disruption of breast architecture

Malignant

grows through tissue without compressing adjacent tissue; may cause retraction of the nipple or dimpling of the skin

Fibrocystic condition:

produce histologic alterations in the terminal ducts and lobules of the breast

Fibrocystic condition:

Clinical presentation

breast lumps and pain and pain the patient feels that fluctuate with every monthly cycle

Fibrocystic condition:

Sonographic appearance

round masses as multiple cysts

Fibroadenoma

most common benign breast tumor

estrogen-dependent for growth

Fibroadenoma

Sonographic appearance

benign characteristics:

• smooth, rounded margins, and low-level homogeneous internal echoes, and may demonstrate posterior enhancement

Galactocele

Milk-filled cyst caused by the obstruction of the lactiferous ducts

easy to be aspirated under ultrasound guidance

Sonographic appears as a complex cyst

Lipoma

consists of entirely of fatty tissue

commonly presents as a palpable mass

sonographic appearance:

• difficult or impossible to detect in a fatty breast

• smooth walls

• hypoechoic

• easily compressible

cystosarcoma phyllodes

most frequent sarcoma of the breast

Sonographic appearance:

• large, hypoechoic tumor with well-defined margins

• decreased through-transmission

• internal shadowing

• variable amounts of shadowing may be noted

Intraductal papilloma

small, benign tumor that grows within the acini of the breast

occurs in women 35-55

predominant symptom- spontaneous nipple discharge

Sonographic appearance:

• Usually small, multiple, and are multicentric

• consist of simple proliferation of duct epithelium projecting outward into a dilated lumen of the duct from one more points

Malignant Conditions

Most breast cancer originates in the Terminal Duct Lobular Units (TCLUs)

2 types of cancer of the breast:

1. sarcoma

2. carcinoma

cancers are generally categorized by:

• where the cancer cells originates (ductal or lobular)

• where the cancer is prone to spreading (invasive or noninvasive)

Breast pathology: MALIGNANT

comedocarcinoma, juvenile breast cancer, papillary carcinoma, ductal carcinoma in situ (DCIS), invasive distal carcinoma (IDC), paget’s disease

Breast pathology: BENIGN

cyst, fibrocystic condition, fibroademoma, lipoma, fat necrosis, acute mastitis, chronic mastitis, abscess, cystosarcoma phyllodes, intraductal papilloma

Ductal carcinoma in situ (DCIS)

intraductal carcinoma

cancer cells that are present inside the ducts but have not yet spread through the walls of the ducts into the fatty tissue of the breast

100% cure rate

sonographic appearance:

• calcifications and ductal enlargement

Invasive ductal carcinoma (IDC)

Most common type of invasive cancer

• 80% of breast cancers

Begins in the ducts and invades the fatty tissue of the breast

has the potential to metastasize via the blood stream or the lymphatic system

Lobular Carcinoma in situ (LCIS)

classified as a precancerous growth that begins in the lobule

confined to the gland and does not penetrate through the wall or the lobule

Sonographic appearance:

• does not for a distinct mass making it difficult to pick up with ultrasound and mammography screening

papillary carinoma

Arises from an intraductal mass or from a benign ductal papilloma

can be invasive or noninvasive

presents with bloody nipple discharge

sonographic appearance:

• a difficult nodular palpable appearance overlaying the skin is a special variant or multiple intraductal papillary carcinoma

Nodules of blue or red discoloration may be found under the skin with ulceration

medullary carcinoma

densely cellular tumor that contains large, round, or oval tumor

tends to occur in younger patients <50 years old

Sonographic appearance:

• well circumscibed

• large

• resembles retro-areolar mass

• has a fairly benign appearance

• clinically- discoloration of the overlying skin