breast cancer... a potential life threatening disease.
Anatomy of breast
*Overview
: Breast shape varies among
patients, but knowing and understanding the anatomy of the breast ensures safe
surgical planning .
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*Vascular
Anatomy and Innervation of the Breast:
The blood supply to the breast
skin depends on the subdermal plexus, which is in communication with deeper
underlying vessels supplying the breast parenchyma. The blood supply is derived
from the following:
·The internal mammary perforators (most notably the second to fifth perforators)
·The thoracoacromial artery
·The vessels to serratus anterior
·The lateral thoracic artery
·The terminal branches of the third to eighth intercostal
perforators
** The
superomedial perforator supply from the internal mammary vessels is
particularly robust and accounts for some 60% of the total breast blood supply.
This rich blood supply allows for various reduction techniques, ensuring the
viability of the skin flaps after surgery.
** Sensory
innervation of the breast is dermatomal in nature. It is mainly derived from
the anterolateral and anteromedial branches of thoracic intercostal nerves
T3-T5. Supraclavicular nerves from the lower fibers of the cervical plexus also
provide innervation to the upper and lateral portions of the breast.
Researchers believe sensation to the nipple derives largely from the lateral
cutaneous branch of T4.
*Breast
Parenchyma and Support Structures:
- The breast is made up of fatty tissue and glandular,
milk-producing tissues. The ratio of fatty tissue to glandular tissue varies
among individuals.
In addition, with the onset of menopause (ie,
decrease in estrogen levels), the relative amount of fatty tissue increases as
the glandular tissue diminishes.
-The base of the breast overlies
the pectoralis major muscle between the second and sixth ribs in the nonptotic
state.
-The gland is anchored to the
pectoralis major fascia by the suspensory ligaments first described by Astley Cooper in 1840. These ligaments run
throughout the breast tissue parenchyma from the deep fascia beneath the breast
and attach to the dermis of the skin. Since they are not taut, they allow for
the natural motion of the breast. These ligaments relax with age and time,
eventually resulting in breast ptosis. The lower pole of the breast is fuller
than the upper pole. (See the image below.) The tail of Spence extends
obliquely up into the medial wall of the axilla.
-The breast overlies the
pectoralis major muscle as well as the uppermost portion of the rectus
abdominis muscle inferomedially. The nipple should lie above the inframammary
crease and is usually level with the fourth rib and just lateral to the
midclavicular line. The average nipple–to–sternal notch measurement in a
youthful, well-developed breast is 21-22 cm; an equilateral triangle formed
between the nipples and sternal notch measures an average of 21 cm per side.
*Musculature Related to the
Breast :
The breast lies over the musculature that encases the
chest wall. The muscles involved include the pectoralis major, serratus
anterior, external oblique, and rectus abdominis fascia.
The blood
supply that provides circulation to these muscles perforates through to the
breast parenchyma, thus also supplying blood to the breast.
Histology of Breast
-Breast can be considered a
modified skin appendage in Mammalians producing milk for the nourishment of the
newborn. The milk is discharged from a collection of 10-20 large ducts opening
through pores in the nipple during lactation.
-Each large duct, also called lactiferous
duct, branches out deep into the breast tissue forming what is called a breast
lobe. Thus, a breast consists of about 10-20 inter-anastomosing lobes separated
from each other by varying amounts of fibro-adipose tissue.
-This photomicrograph shows six
(6) lactiferous ducts (arrows) that run from the nipple to branch down into
successive smaller ducts until the formation of “terminal duct lobular unit
(TDLU).”
Cancer breast
Types of cancer breast
A- Ductal Carcinoma:
1-Ductal Carcinoma In Situ -DCIS:
It is the most common type of non-invasive breast cancer.This
type of cancer starts inside the milk ducts and remains in its original place
"non-invasive" .DCIS isn’t life-threatening, but having DCIS
can increase the risk of developing an invasive breast cancer later on.
Signs and symptoms*
2-Invasive Ductual Carcinoma-IDC:
In some cases, the first sign is a lump in the breast
,that the doctor can feel
Invasive ductal carcinoma (IDC) " infiltrating ductal carcinoma"
is the most common type of breast cancer. About 80% of all breast cancers are
invasive ductal carcinoma
cancer begins in the milk ducts and then invades
the tissues of the breast. Over time it can
spread to the lymph nodes and to other areas of the body.
*Signs and symptoms:
At first, invasive ductal carcinoma may not cause any
symptoms
In
some cases, the first sign is a lump in the breast ,that the doctor can feel
3-Paget's Disease of the Nipple (PD):
-Paget's Disease of the Nipple is a form of ductal
carcinoma in situ, that extends from the ducts of the nipple into the
contiguous skin and surrounding areola.
*signs and symptoms:
-Paget's disease causes the skin on and around the
nipple to become red, sore, and flaky, or scaly. At first, these symptoms tend
to come and go.
-Over time, symptoms of Paget's disease usually
worsen and may include:
1-itching, tingling, and/or a burning sensation
2-pain and sensitivity
3-scaling and thickening of the skin
4-flattening of the nipple
yellowish or bloody discharge from the nipple-
B- Lobular Carcinoma:
1-Lobular Carcinoma in situ (LCIS):
It is characterized by proliferation, in one or
more terminal ducts In technical terms, LCIS is not really considered a cancer,
as much as it is a form of lobular neoplasia. the cells of LCIS rarely develop
central necrosis or calcify. Therefore, they almost never present as a
discrete mass or are palpable.
*Signs and symptoms:
LCIS usually does not cause any signs or symptoms,
such as a lump or other visible changes to the breast. LCIS may not always show
up on a screening mammogram because LCIS often lacks microcalcifications.
It’s
believed that many cases of LCIS simply go undiagnosed, and they may never
cause any problems.
2- Infiltrating Lobular Carcinoma (ILC):
-similar to IDC, it has the potential to metastasize and spread to
other parts of the body, via the lymphatics. Fortunately, infiltrating
lobular carcinoma has a much lower incidence than IDC
*signs and symptoms:
-At first, invasive lobular carcinoma may not cause any symptoms.
-Sometimes, an abnormal area turns up on a screening
mammogram (x-ray of the breast), which leads to further testing. Invasive
lobular carcinomas tend to be more difficult to see on mammograms than invasive
ductal carcinomas are. That’s because instead of forming a lump, the cancer
cells more typically spread to the surrounding connective tissue (stroma) in a
line formation. he first sign of ILC is a thickening or hardening in the breast
that can be felt, rather than a distinct lump. Other possible symptoms include
an area of fullness or swelling, a change in the texture of the skin, or the
nipple turning inward.
*Diagnosis:
-diagnostic services for patients with breast cancer, include
digital mammography,magnetic resonance imaging (MRI), ultrasound, stereotactic breast biopsies, MRI-guided breast biopsies and surgical
biopsies.
*Treatment:
Treatments of breast cancer include Surgery, Mastectomy, Radical
mastectomy, Modified radical mastectomy, Radiation therapy, Chemotherapy
*Risk factors:
· Age: The chances of breast cancer increase as you get older.
· Family history: The risk of breast cancer is higher among women who have
relatives with the disease.
