5 Breast Modified sweat glands Glandular tissue embedded within superficial fascia of anterior chest wallModified sweat glandsOverlying pectoral musclesRudimentary in males and pre-pubertal femalesSize and shape of adult female breast variesDetermined by amount of fat surrounding glandular tissue
6 Extent-BaseExtending from lateral border of sternum to midaxillary line and from 2nd to 6th ribs.Majority of breast overlies deep pectoral fascia of pec major muscle, with remainder overlying fascia of serratus anteriorRetromammary spaceA potential space filled with loose connective tissueBreast is separated from pectoralis major muscleAxillary tail (of Spence)A small part of mammary gland extend toward axilla
9 Structure of Breast Areola Surrounds the nipple Circular pigmented area of skinBreast composed of 15 to 20 lobules of glandular tissueFormed by septa of suspensory ligamentsEach lobule is drained by a lactiferous ductEach lactiferous duct opens on nippleFirmly attached to overlying skin bySuspensory ligaments (of Cooper)
16 Lymphatic Drainage of Breast Lymph from nipple, areola, and lobules of mammary glands- subareolar lymphatic plexusFrom there, a system of interconnecting lymphatic channels drains lymph to various lymph nodesMajority (75%) of lymph, especially from lateral quadrants→ pectoral nodes→ axillary nodesRemaining lymph, especially from medial quadrants→ parasternal lymph nodes along internal thoracic vessels
19 Some lymph from lower quadrants→ inferior phrenic nodes Lymph from medial quadrants can cross to opposite breast via parasternal nodesSecondary metastases of breast carcinoma can spread to opposite breast in this way
20 Major Routes of Metastasis Channels to Contralateral BreastAxillary Lymph Channels6. Lymph Vessels of Mammary Glands (41)Subdiaphragmatic Lymph Channels
21 Carcinoma of the Breast Approximately 60% of carcinomas of the breast occur in the upper lateral quadrant.The cancer cells are swept along the lymph vessels and follow the lymph stream. The entrance of cancer cells into the blood vessels accounts for the metastases in distant bones.The lymphatic spread of cancer to the opposite breast, to the abdominal cavity, or into lymph nodes in the root of the neck is caused by obstruction of the normal lymphatic pathways by malignant cells or destruction of lymph vessels by surgery or radiotherapy.
22 Peau d’orange sign Leathery thickening of the skin Often dimpled and has prominent poresThat gives the skin the appearance of orange peelThe dimples and the pores results from shortening of the suspensory ligament because of cancerous invasion
25 Examination of Breast Clinically breast is divided into quadrants: UI: upper innerUO: upper outer (includes axillary tail)LI: lower innerLO: lower outerBreast palpation-Circular fashion, beginning with nipple and moving outwardPalpation should extend into axilla to palpate axillary tailsAfter palpation of one breast, other should be palpated in same wayExamine skin of breast for a change in texture or dimpling (peau d'orange sign) and nipple for retraction→ these signs indicate an underlying pathology
29 Mammography Mammography is a radiographic examination of the breast This technique is extensively used for screening the breasts for benign and malignant tumors and cysts.Extremely low doses of x-rays are used so that the dangers are minimal and the examination can be repeated often.Its success is based on the fact that a lesion measuring only a few millimeters in diameter can be detected long before it is felt by clinical examination.
31 MastectomyA simple mastectomy in which the pectoral muscles are left intact. The axillary lymph nodes, fat, and fascia are removed.Radical mastectomy is designed to remove the primary tumor and the lymph vessels and nodes that drain the area.