Transcript الشريحة 1

•Breasts ( Mammary glands )
•Structure & physiology :
•The breasts are originated from the skin.
•They resemble the sweat glands in structure & development
& they are regarded as modified sweat glands .
•Each breast consists of 15-25 lobes. Each lobe is drained by
a duct that emerges at the nipple as an independent opening.
•The lobes are separated by interlobular connective tissue &
adipose tissue . The lobes are sub-divided into lobules by
layer of connective tissue & adipose tissue .
•Each lobe has an excretory lactiferous ducts that opens
independently at the nipple .
•The secretory portion consists of a basement membrane ,
layer of myoepithelial cells & a layer of low columnar cells .
•In males The development is transient & is followed by
involution .
In females the development continues during
adolescence & reaching final development at the
end of pregnancy .
Mild cyclic changes involving hyperplasia followed
by involution occur with each menstrual cycle.
The normal development of the breast at puberty is
related to an increase of oestrogen in the
circulation.
Also during pregnancy oestrogen plays a role in the
development of the ductal portion of the glandular
tissue,while progesterone is responsible for acinar
development(glands).
After the menopause , involutionary changes
occur, with dense connective tissue gradually
replacing the glandular tissue & the breast
decreasing in size.
Congenital abnormalities :
1. Poly mastia : It is the presence of more than two
breasts. These may occur any where along the milkline which extends from the axilla to the groin .
2. Polythelia : It is the presence of accessory nipples .
Inflammation of the breast :
1. Acute mastitis & breast abscess :
Aetiology : It is almost always associated with lactation &
a cracked nipple through which staph or strepto enter to
the breast tissue .
Pathology :
Gross : There may be generalized red ,painful swelling of
the breast or a localized abscess may form in a single
breast lobe .
Micro. : There is an acute suppurative inflammation &
with abscess formation,
The axillary lymph nodes are frequently swollen & show
reactive hyperplasia .
Results : It may result in extensive destruction & fibrous
scarring of the breast if not treated early .
2. Chronic inflammatory mastitis :
True chronic inflammation of the breast due to
bacterial infection is uncommon . Most cases are due
to incomplete resolution of acute mastitis in the
lactating breast or due to chronic breast abscess .
3. Tuberculosis :
It is very rare but may occur secondary to tuberculosis of
the lungs .
Traumatic fat necrosis of the breast :
It is caused by a trauma to the breast which cause
disruption of fat cells & allow the escape of fat globule
into the surrounding tissue which cause foreign body
giant cell reaction , foamy cells & later dense fibrous
tissue .
The hardness of this lesion & the fibrous reaction
which may result in fixation to the surrounding tissue
may be misdiagnosed as carcinoma .
Mammary duct ectasia :
It is dilatation of the mammary ducts. The dilated ducts
are filled with neutral fat & cellular debris leading to a
pale or coloured nipple discharge.
The contents of the ducts may escape to the periductal
tissue & causing inflammatory response
Fibrocystic Disease
It may occur at any age from puberty onwards but is common
about the time of menopause & afterwards .
Structural changes : It consists of :
a. Fibrosis :
b. Cyst formation : It occurs as a result of dilatation of ducts .
The cysts are lined by flattened cuboidal epithelium. Some
cysts may show metaplasia of thelining epithelial cells
which become large , columnar with eosinophilic cytoplasm
& it is called apocrine metaplasia .
c. Adenosis : There is formation of new breast lobules as a
result of proliferation of the breast epithelium of ducts &
acini. There may be increase in the fibrous stroma
producing distortion of the acinar pattern & eventually
sclerosis . This is called sclerosing adenosis .
It is characterized by proliferation of the epithelium &
connective tissue of the breast with cystic dilatation of
the ducts , due to ovarian hormonal imbalance .
The nature of the fibrocystic changes :
The cyclic changes in the ovary , with alternating
oestrogen & progesterone secretion , produce effects
not only in the endometrium but also in the breasts.
Thus there is overgrowth of both epithelium & stroma
during the cycle with a return to normal at the end of
each cycle. As aresult of hormonal imbalance either the
epithelium or the stroma or both may remain in an
abnormal proliferative state to produce nodular , lumpy
or cystic breasts .
Proliferative Breast Diseases Without
Atypia
.presentation
-mammographic densities or
calcifications
-incidental findings in biopsies
-nipple discharge
Epitheliosis : The essential feature is increase
in the thickness of the epithelium of the wall of
ducts & acini due to hyperplasia of the
epithelium of ducts & acini . Thus the cells are
several layers in depth & the lumen may be
completely obliterated by this proliferation .
Fibrocystic changes is a benign condition :
Adenosis & Sclerosing variants have no
predisposition to carcinoma. However
epitheliosis carries risk of subsequent
malignant Changes .
Tumours of the breast
Benign tumours : The main tumours are :
1. Fibroadenoma : It is the commonest benign
tumour of the breast . It consists of both
stromal & epithelial elements.
Fibroadenoma is small well circumscribed
rounded mass & movable.
Fibro-Adenoma
.
.presents as
-palpable mass in young women
-mammographic density or calcification
in old women
Micro. :
2 types :
A.Pericanalicular : It consists of fibrous
tissue surrounding groups of epithelial
acini
B.Intracanalicular : It is composed of
fibrous tissue surrounding epithelial
clefts which represent compressed
ducts
C.. Mixed
2. Duct papilloma : It occurs as a
pedunculated tumour which forms within
a distended duct. It consists of a
branching fibro vascular stromal core
covered by cuboidal epithelium . It
causes blood discharge from the nipple .
Carcinoma
.the most common cancer in women
.risk factors
-age, rare before 25 years
-earlier menarche and later menopause
-age at 1st pregnancy
-first-degree relatives with breast
cancer
-prior breast biopsies with atypical
hyperplasia
-race
•.additional risk factors
-estrogen exposure
-radiation exposure
-carcinoma of the contralateral breast
or endometrium
-geographic influence
-diet
-obesity
-lack of exercise
-lack of breast feeding
-environmental toxins
-tobacco
.etiology and pathogenesis
-major factors are genetic and
hormonal
.hereditary breast cancer, affect
mainly premenopausal women
-25% are attributed to 2 autosomal
dominant tumor-suppressor
genes(BRCA1, BRCA2)
-other genes mutations form 10%
-remaining 65% of familial breast
cancers are unexplained
•
.sporadic breast cancer, affect mainly
postmenopausal women
-are related to hormone exposure
-majority of cancers overexpress ER
.the role of estrogen in breast cancer
-its metabolites can cause mutation or
generate DNA-damaging free radicals
-via its hormonal action, it directly
stimulates proliferation of epithelial cells
.morphology
-comedocarcinoma
-solid
-cribriform
-papillary
-micropapillary
.many cases will progress to invasive
carcinoma
.mastectomy is curative in 95% of cases
Paget Disease Of The Nipple
.presents as a unilateral erythematous
eruption with a pruritic scaly lesion
.palpable mass is present in up to 60%
cases, which almost always is
associated with an underlying invasive
carcinoma (poorly differentiated)
.malignant cells (Paget cells) extend
from DCIS into nipple skin
of
Invasive Carcinoma
.almost always presents as a palpable
mass
.most common histologic types
-invasive carcinoma, no special type
(NST)
-invasive lobular carcinoma, has a
greater incidence of multi-centricity
and bi-laterality
Spread of breast cancer :
1. Direct : It invades the breast tissue &
overlying skin with ulceration & nipple
retraction . It may invade the underlying
muscle & chest wall .
2. Lymphatics :
a. Permeation of the local dermal lymphatics by
tumour cause blockage of lymphatics &
oedema of the skin producing a Peau d orange.
b. Dermal lymphatic invasion may produce
multiple tumour nodules with thickening of skin
– Cancer en cuirasse .
c. Invasion of axillary lymph nodes .
d. Invasion of internal mammary lymph nodes .
e. Invasion of supraclavicular lymph nodes .
3. Blood : spread to lung , liver & bones .
Gynaecomastia :
It is enlargement of the breast tissue of
males,which is usually caused by proliferation
of connective tissue & ducts of the breast. It
may be unilateral or bilateral .
Aetiology :
1. Endocrine disturbances : due to increase
oestrogen .
2. Testicular tumours e.g. teratoma.
3. Oestrogen therapy e.g. for carcinoma of the
prostate
4. Ciirrhosis : Due to failure of detoxification of
oestrgen .
5. Drugs : e.g. digitalis , tricyclic compounds.