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Age-Related Changes of the Breast in US and MR
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IOANNA TZOVARA, MD Radiologist
IASO General Hospital, Athens, Greece
Embryology of the Breast
Changes in the Breast during Childhood
Breast Development during Puberty
Mature Breast
Menstrual Cycle Breast Changes
Changes in the Breast during Pregnancy
Changes in the Breast during and after Lactation
Changes in the Breast during and after Menopause
Changes in the Breast with Hormone Replacement Therapy
At about the sixth week of embrionic life, breast precursor develops from ectodermal origin
The “milk line” extends from the axillary area to the groin region
Portions of the milk line atrophy except in the region of the 4th intercostal space, from which
mammary tissue develops
Embryology of the Breast
Changes in the Breast during Childhood
Breast Development during Puberty
Mature Breast
Menstrual Cycle Breast Changes
Changes in the Breast during Pregnancy
Changes in the Breast during and after Lactation
Changes in the Breast during and after Menopause
Changes in the Breast with Hormone Replacement Therapy
Branching of main ducts (Terminal Duct Lobular Units) which consist of an interlobular duct and an
associated lobule
Branching of main ducts (Terminal Duct Lobular Units)
Proliferation and enlargement of adipose cells
Increasing of stroma and blood vessels
From infancy to just before puberty, there is no difference between the female and male
breasts
Two or three years prior to menarche, female’s mammary gland visible enlarges
U/S shows a homogeneous tissue of moderate echogenity
Breast parenchyma appears as a small island of retroareolar tissue
Embryology of the Breast
Changes in the Breast during Childhood
Breast Development during Puberty
Mature Breast
Menstrual Cycle Breast Changes
Changes in the Breast during Pregnancy
Changes in the Breast during and after Lactation
Changes in the Breast during and after Menopause
Changes in the Breast with Hormone Replacement Therapy
With the beginning of female puberty, release
of estrogen (ductal development), at first alone, and
then in combination with progesterone (lobulo-
alveolar development) when the ovaries functionally
mature, cause the breasts to undergo changes
which culminate in the fully mature form
Glands enlarge, fat and connective tissues
proliferate
Pubertal breast development is divided into five phases called Tanner Stages
This process on average takes 3 to 4 years and is usually
complete by age 16 to 20 years
The adolescent breast consists almost entirely of glandular
tissue with very little fat
6-year-old girl: small area of ill-defined echogenic tissue in the
retroareolar region
13-year-old girl: echogenic nodule with a retroareolar, stellate,
hypoechoic focus
13-year-old girl: more echogenic, glandular tissue with a
central spider-shaped hypoechoic focus
16-year-old girl: more echogenic fibroglandular tissue with a
central hypoechoic nodule. Also increased subcutaneous fat
anterior to the glandular tissue
16-year-old girl: echogenic fibroglandular tissue without a
central hypoechoic focus
Suprammamary fascia strongly
echogenic
Subcutaneous & retromammary
layers of fat are quite narrow
Glandular tissue is relatively
hypoechoic (sometimes appears
as a hypoechoic nodule)
Cysts can develop at an early age due to incomplete development of the terminal ductules
The excessive proliferation of intralobular connective tissue can lead to the development of
fibroadenomas
Very difficult to evaluate radiographically U/S is the preffered modality for investigation
Embryology of the Breast
Changes in the Breast during Childhood
Breast Development during Puberty
Mature Breast
Menstrual Cycle Breast Changes
Changes in the Breast during Pregnancy
Changes in the Breast during and after Lactation
Changes in the Breast during and after Menopause
Changes in the Breast with Hormone Replacement Therapy
The fully developed human breasts lie on
the anterior chest wall atop the pectoralis
major muscle
It extends from about the second rib to
seventh bilaterally
Is composed of adipose (30%), glandular
(10-35%) & fibrous-connective (50%) tissues
Each breast consists of ~ 20 secretory
tissue lobes
The glandular apparatus is
composed of a branching system of
ducts, organized in radial pattern
spreading outward and downward
Subareolar ducts widen to form
lactiferous sinuses which exit through
10-15 orifices on the nipple
The ducts end blindl in clusters of
spaces called acini (milk forming glands)
An important anatomical space
called the retromammary space lies
between the pectoralis muscle and
the breast. The space is filled with a
layer of fat tissue
Projecting through this fat layer is
a deep fascia that extends into the
pectoralis muscle. This network of
connective tissue fascia (suspensory
ligaments of Cooper) gives shape
and support to the breast
parenchyma.
Each month the epithelium and
stroma undergo cyclic stimulation
The breast increases in size,
tenderness, firmness and blood
supply
Ducts enlarge with an increase
in the number of cells lining the ducts
and the breast retains more fluid
The breasts are least engorged
7-10 days after the beginning of
menses Hormones affecting the breast
Normal skin appears as a white
line of 3mm or less
Significant individual variations
can occur both in the relatively
proportion of hyperechoic glandular
tissue and in the more hypoechoic
fatty tissue
Skin (1-3mm)
Subcutaneous fat transeversed
by Cooper ligaments & superficial
fascia (dark layer criss-crossed by
bright lines that extend to the skin and
hyperechoic band separating the fat
from the mammary gland)
fibroglandular tissue + lactiferous ducts
Breast parenchyma (sponge with
large pores–lobules which are clearly
distinguisable from the surrounding
breast tissue
Interlobular connective tissue-white
lines
Lactiferous ducts as tubular
hypoechoic structures
Deep fascia –thin echogenic band
Retromammary fat hypoechoic
Pectoralis major muscle fascia
(hypoechoic layer with an internal pattern
of parallel linear echoes)
Rib surface-broad, convex, echogenic
stripe with posterior acoustic shadowing
Mature Breast 1st half
Mature Breast 2nd half
Mature Breast
Mature Breast (Dense Breasts)
Premenopausal Breast
Premenopausal Breast (exam day)
Occasionally, a milky or patchy diffuse enhancement, sometimes focal
enchancement, can appear in normal glandular tissue before and after
menstruation.
Examination is recommended between day 6 and 12 of the menstrual cycle
Normal Breast - Gd Enhancement Kinetics
Very Dense Breast
Mature Breast 1st half
Embryology of the Breast
Changes in the Breast during Childhood
Breast Development during Puberty
Mature Breast
Menstrual Cycle Breast Changes
Changes in the Breast during Pregnancy
Changes in the Breast during and after Lactation
Changes in the Breast during and after Menopause
Changes in the Breast with Hormone Replacement Therapy
First trimester:
Proliferating glandular epithelium causes branching of the ducts
Amount of fat and connective tissue decreases
• Decreased echogenicity of breast tissue
• Echo pattern appears finely glandular
Second trimester:
Alveolar epithelium differentiates into a secretory epithelium
Arborization of the alveoli causes enlargement of the breast
Colloid accumulates in the alveoli
Distended lactiferous ducts are discernible as tubular
extremely hypoechoic or anechoic structures
Third trimester:
Differentiation of the milk-producing cells and synthesis of milk.
In the last days before delivery, increase of blood flow in the breast and filling of the alveoli
and ducts with colostrum
Young pregnant woman: dilated anechoic ducts seen in cross section
deep to the areola
Adenosis of Pregnancy Diminution of fibrous stroma
Formation of new acini or lobules
Cysts, fibroadenomas and
other benign breast change can develop or if already
existing may be enlarged
Embryology of the Breast
Changes in the Breast during Childhood
Breast Development during Puberty
Mature Breast
Menstrual Cycle Breast Changes
Changes in the Breast during Pregnancy
Changes in the Breast during and after Lactation
Changes in the Breast during and after Menopause
Changes in the Breast with Hormone Replacement Therapy
Immediate post partum enlargement
due to colostrum accumulation
Milk secreted into alveoli 3 - 7 days post
partum
Breastfeeding stimulates prolactin
Ductal structures (notably central) are
dilated
Fat content of breast decreases
(subcutaneous fat layer is thinned)
+
+
Strong generalized contrast enhancement (increased vascular
permeability) is expected in the engorged breast
There is generalized parenchymal involution,
with variable degree
Periductal and perivascular stromal tissue
increases
Alveolar cells and ductal branches regress
2 months after Pregnancy (no lactation)
Embryology of the Breast
Changes in the Breast during Childhood
Breast Development during Puberty
Mature Breast
Menstrual Cycle Breast Changes
Changes in the Breast during Pregnancy
Changes in the Breast during and after Lactation
Changes in the Breast during and after Menopause
Changes in the Breast with Hormone Replacement Therapy
The majority of breasts cancers occur at this age
Glandural tissue atrophies, connective tissue becomes less cellular and the amount
of collagen decreases
The breast initially increases in fatty tissue (perimenopausal), then decreases in
glandular tissue (post-menopausal) and decreases in firmness.
: fat 20%, fibrous 60%, glandular 10-35%
: fat 40%, fibrous 55%, glandular 5-20%
(35% of women pattern of reproductive age)
: fat 50%, fibrous 50%, glandular <10%
: the breast parenchyma has disappeared completely in 71% of women,having
been replaced by fat
Islands of residual parenchyma are clearly
visible as small, hypoechoic “pores” within the
dense, hyperechoic connective tissue
Cooper ligaments are thickened
Development of small retention-type cysts
may be seen due hormonal alterations
Central dilatations of the main ducts (up to
10mm) are commonly seen
Involution of the mammary lobules
progresses rapidly and can be classified
as: lipofibromatus (predominately fat) or fibrolipomatus
Postmenopausal Breast
Fatty tissue has a high signal intensity
Residual parenchyma and connective-tissue structures have low signal intensity
Fatty Breast
Old Woman Heart Failure
Patients on long-term immunosuppresing corticoid
therapy show complete lipomatous breast involution
after taking the medication for many years
Embryology of the Breast
Changes in the Breast during Childhood
Breast Development during Puberty
Mature Breast
Menstrual Cycle Breast Changes
Changes in the Breast during Pregnancy
Changes in the Breast during and after Lactation
Changes in the Breast during and after Menopause
Changes in the Breast with Hormone Replacement Therapy
Hormone replacement delays involutional changes in the breast
Generalized increase in the extend and density of partially involuted parenchyma
Selective Estrogen Receptor Modulator - SERMs