Breast (for students)

The breasts consist of mammary glands and associated skin and connective tissues. The mammary glands are modified sweat glands in the superficial fascia anterior to the pectoral muscles and the anterior thoracic wall (Fig. 3.16).

The mammary glands consist of a series of ducts and associated secretory lobules. These converge to form 15 to 20 lactiferous ducts, which open independently onto the nipple. The nipple is surrounded by a circular pigmented area of skin termed the areola.

A well-developed, connective tissue stroma surrounds the ducts and lobules of the mammary gland. In certain regions, this condenses to form well-defined ligaments, the suspensory ligaments of breast, which are continuous with the dermis of the skin and support the breast. Carcinoma of the breast creates tension on these ligaments, causing pitting of the skin.

In nonlactating women, the predominant component of the breasts is fat, while glandular tissue ismore abundant in lactating women.

The breast lies on deep fascia related to the pectoralis major muscle and other surrounding muscles.A layer of loose connective tissue (the retromammary space) separates the breast from the deepfascia and provides some degree of movement over underlying structures.

The base, or attached surface, of each breast extends vertically from ribs II to VI, and transversely from the sternum to as far laterally as the midaxillary line.

It is important for clinicians to remember when evaluating the breast for pathology that the upperlateral region of the breast can project around the lateral margin of the pectoralis major muscle andinto the axilla. This axillary process (axillary tail) may perforate deep fascia and extend as far as superiorly as the apex of the axilla.

The breast lies on top of the pectoral muscle, which in turn rests on the thoracic cage. Rough boundaries of the breast are as follows:a. Superior aspect of the breast is bounded by the clavicleb. Inferiorly by the inframamary crease ("bra line")c. Medially by the sternumd. Laterally by the axilla

Arterial supply

The breast is related to the thoracic wall and to structures associated with the upper limb; therefore,vascular supply and drainage can occur by multiple routes (Fig. 3.16):laterally, vessels from the axillary artery-superior thoracic, thoraco-acromial, lateral thoracic,and subscapular arteries;medially, branches from the internal thoracic artery;the second to fourth intercostal arteries via branches that perforate the thoracic wall andoverlying muscle.(40th)The breasts are supplied by branches of the axillary artery, the internal thoracic artery, and some intercostal arteries. The axillary artery supplies blood via the superior thoracic artery, the pectoral branches of the thoracoacromial artery, the lateral thoracic artery (via branches which curve around the lateral border of pectoralis major to supply the lateral aspect of the breast) and the subscapular artery. The internal thoracic artery supplies perforating branches to the anteromedial part of the breast. The second to fourth anterior intercostal arteries supply perforating branches more laterally in the anterior thorax: the second perforating artery is usually the largest, and supplies the upper region of the breast, and the nipple, areola and adjacent breast tissue.

Venous drainage

Veins draining the breast parallel the arteries and ultimately drain into the axillary, internal thoracic, and intercostal veins

(40th)Blood drains from the circular venous plexus around the areola and from the glandular tissue of the breast into the axillary, internal thoracic and intercostal veins via veins that accompany the corresponding arteries. Individual variation is common.

(Mcleods)Fibrocystic changes

Fibrocystic changes are rubbery, bilateral and benign, and most prominent premenstrually, but investigate any new focal change in young women which persists after menstruation. These changes and irregular nodularity of the breast are common, especially in the upper outer quadrant in young women.

FibroadenomasThese smooth, mobile, discrete and rubbery lumps are the second most common cause of a breast mass in women under 35 years old. These are benign overgrowths of parts of the terminal duct lobules.

Breast cystsThese are smooth flid-filed sacs, most common in women aged 3555 years. They are soft and flctuant when the sac pressure is low but hard and painful if the pressure is high. Cysts may occur in multiple clusters. Most are benign, but investigate any cyst with bloodstained aspirate or a residual mass following aspiration, or which recurs after aspiration.

What is a fibroadenoma?Breasts are made up of lobules (milk-producing glands) and ducts (tubes that carry milk to the nipple), which are surrounded by glandular, fibrous supporting tissue and fatty tissue. Fibroadenomas develop from a lobule. The glandular tissue and ducts grow over the lobule and form a solid lump.

Fibroadenomas are benign (not cancer) and dont increase the risk of developing breast cancer. They are thought to occur because ofan increased sensitivity to the female hormone oestrogen. A fibroadenoma usually has a smooth rubbery texture and can move easily under the skin. Fibroadenomas are usually painless, but some people may feel some tenderness or even pain. Fibroadenomas are very common and it is not unusual to have more than one. Often developing during puberty, they are mostly found in young women, but can occur at any age. Most fibroadenomas are about 1 to 3cm in size and are called simple fibroadenomas. Occasionally, a fibroadenoma can grow to more than 5cm and may be called a giant fibroadenoma. Those found in teenage girls may be called juvenile fibroadenomas. Most fibroadenomas stay the same size. Some get smaller and some eventually disappear over time. Sometimes fibroadenomas get bigger, particularly in teenage girls and pregnant and breastfeeding women, but often get smaller again.

(mcleod)Ask her to rest her hands on her thighs to relax the pectoral muscles (Fig. 10.12A). Face the patient and look at the breasts for- asymmetry local swelling skin changes nipple changes. Ask the patient to press her hands firmly on her hips to contract the pectoral muscles and inspect again (Fig. 10.12B). Ask her to raise her arms above her head and then lean forward to expose the whole breast and exacerbate skin dimpling (Fig. 10.12C and D). Ask her to lie with her head on one pillow and her hand under her head on the side to be examined (Fig. 10.13). Hold your hand flat to her skin and palpate the breast tissue, using the palmar surface of your middle three fingers.Compress the breast tissue firmly against her chest wall. View the breast as a clock face. Examine each hour of theclock from the outside towards the nipple, including underthe nipple (Fig. 10.14). Compare the texture of one breastwith the other. Examine all the breast tissue. The breastextends from the clavicle to the upper abdomen and fromthe midline to the anterior border of latissimus dorsi(posterior axillary fold). Define the characteristics of anymass (Box 3.11 ). Elevate the breast with your hand to uncover dimpling overlyinga tumour which may not be obvious on inspection. Is the mass fixed underneath? With the patients hands onher hips, hold the mass between your thumb and forefinger.Ask her to contract and relax the pectoral muscles alternatelyby pushing into her hips. As the pectoral muscle contracts,note whether the mass moves with it and if it is separate whenthe muscle is relaxed. Infitration suggests malignancy. Examine the axillary tail between your finger and thumb as itextends towards the axilla. Palpate the nipple by holding it gently between your indexfinger and thumb. Try to express any discharge. Massage thebreast towards the nipple to uncover any discharge. Note thecolour and consistency of any discharge, along with thenumber and position of the affected ducts. Test any nippledischarge for blood using urine-testing sticks. Palpate the regional lymph nodes, including the supraclaviculargroup. Ask the patient to sit facing you, and support the fullweight of her arm at the wrist with your opposite hand. Movethe flat of your other hand high into the axilla and upwardsover the chest to the apex. This can be uncomfortable forpatients, so warn them beforehand and check for anydiscomfort. Compress the contents of the axilla against thechest wall. Assess any palpable masses for- size consistency fixation. Examine the supraclavicular fossa, looking for any visualabnormality. Palpate the neck from behind and systematicallyreview all cervical lymphatic chains (p. 54).Self breast exam (breast cancer org)Step 1:Begin by looking at your breasts in the mirror with your shoulders straight and your arms on your hips.Here's what you should look for: Breasts that are their usual size, shape, and color Breasts that are evenly shaped without visible distortion or swellingIf you see any of the following changes, bring them to your doctor's attention: Dimpling, puckering, or bulging of the skin A nipple that has changed position or an inverted nipple (pushed inward instead of sticking out) Redness, soreness, rash, or swelling

Step 2:Now, raise your arms and look for the same changes.Step 3:While you're at the mirror, look for any signs of fluid coming out of one or both nipples (this could be a watery, milky, or yellow fluid or blood).

Step 4:Next, feel your breasts while lying down, using your right hand to feel your left breast and then your left hand to feel your right breast. Use a firm, smooth touch with the first few finger pads of your hand, keeping the fingers flat and together. Use a circular motion, about the size of a quarter.Cover the entire breast from top to bottom, side to side from your collarbone to the top of your abdomen, and from your armpit to your cleavage.Follow a pattern to be sure that you cover the whole breast. You can begin at the nipple, moving in larger and larger circles until you reach the outer edge of the breast. You can also move your fingers up and down vertically, in rows, as if you were mowing a lawn. This up-and-down approach seems to work best for most women. Be sure to feel all the tissue from the front to the back of your breasts: for the skin and tissue just beneath, use light pressure; use medium pressure for tissue in the middle of your breasts; use firm pressure for the deep tissue in the back. When you've reached the deep tissue, you should be able to feel down to your ribcage.

Step 5:Finally, feel your breasts while you are standing or sitting. Many women find that the easiest way to feel their breasts is when their skin is wet and slippery, so they like to do this step in the shower. Cover your entire breast, using the same hand movements described in step 4.