Breast (mammary gland) part-5

BREAST (MAMMARY GLAND) PART-5

LYMPHATIC DRAINAGE

Lymph nodes draining the breast

Ø The lymph from the breast is drained into the fol group of lymph nodes;

  1. Axillary lymph nodes lying in the axilla and divided into the following four group:(a) anterior/pectoral, (b)posterior© central and lateral

  2. Internal mammary nodes lying along the internal thoracic vessels.

  3. Supraclavicular nodes lying above the clavicle.

  4. Posterior intercostal spaces in front of the head of the ribs.

  5. Cephalic (deltopectoral) nodes lying in the deltopectoral groove.

SPECIAL FEATURES

Ø In addition to the above-mentioned nodes,the lymph from breast also drains into subdiaphragmatic and subperitoneal lymph plexuses.

Lymphatics Draining the Breast

Ø The lymphatics draining the breast are divided into two groups: (a) superficial and (b) deep.

Ø Superficial lymphatics drain the skin of the breast except that of nipple and areola.

Ø Deep lymphatics drain the parenchyma of the breast, and skin of the nipple and areola. A plexus of lymph vessels deep to the areola is called subareolar plexus of Sappey.The subareolar plexus and most of the lymph from the breast drain into the anterior group of axillary lymph nodes.

Ø The superficial lymphatics of the breast of one side communicate with those of the opposite side. Consequently the unilateral malignancy may become bilateral.

The lymphatic drainage from the breast occurs as follows:

  1. The lymph from lateral quadrants of the breast is drained into anterior axillary or pectoral group of lymph nodes. These lymph nodes are situated deep to the lower border of pectoralis minor.

  2. The lymph from medial quadrants is drained into internal mammary lymph nodes situated along the internal mammary artery. Some lymphatics may go to the internal mammary lymph nodes of the opposite side.

  3. A few lymph vessels from the lower lateral quadrant of the breast follow the posterior intercostal arteries and drain into posterior intercostal nodes located along the course of these arteries.

  4. The few lymph vessels from the lower medial quadrant of the breast pierce the anterior abdominal wall and communicate with subdiaphragmatic and subperitoneal lymph plexuses.

  5. The lymph vessels from the deep surface of the breast pierce pectoralis major and clavipectoral fascia to drain into the apical group of axillary lymph nodes.

SPECIAL FEATURES

Ø About 75% of the lymph from the breast is drained into axillary nodes, 20% into internal mammary lymph nodes, and 5% into the posterior intercostal lymph nodes.

Ø Among the axillary lymph nodes, most of the lymph drains into the anterior axillary nodes and the remaining into posterior and apical groups. The lymph from anterior and posterior groups first goes to the central and lateral groups, and then through them into the supraclavicular lymph nodes.

Clinical correlation

Ø Breast cancer (carcinoma of the breast): It is one of the most common cancers in the females. It arises from the epithelial cells of the lactiferous ducts. In about 60% cases, it occurs in the upper lateral quadrant and commonly affects females between 40–60 years of age. Clinically it presents as:

a) Presence of a painless hard lump.

b) Breast becomes fixed and immobile, due to infiltration of suspensory ligaments.

c) Retraction of skin, due to infiltration of suspensory ligaments.

d) Retraction of nipple due to infiltration and fibrosis of lactiferous ducts.

e) peau d’orange’ appearance of the skin (i.e., skin giving rise to appearance like that of the skin of the orange) due to obstruction of superficial lymphatics.

· The knowledge of lymphatic drainage of the breast is of great clinical importance due to high percentage of occurrence of cancer in the breast and its subsequent dissemination of cancer cells (metastasis) along the lymph vessels to the regional lymph nodes. In classical operation of radical mastectomy, whole of breast is removed along with axillary lymph nodes, and pectoralis major and minor muscles.

· Some lymph vessels from the inferomedial quadrant of the breast communicate with the subperitoneal lymph plexus and carry cancer cells to it. From here cancer cells migrate transcoelomically and deposit on the ovary producing a secondary tumor in ovary called Krukenberg’s tumor.

· The cancer of breast is a serious and often a fatal disease in women. The mammography and regular self-examination of the breast help in early detection of the breast cancer and effective treatment.

Ø The six steps of breast self-examination are as follows :

  1. Stand in front of a long mirror and inspect both breasts for any discharge from the nipples, puckering, or dimpling of the skin. Now look for any change in shape or contour of the breasts.

  2. Clasp hands behind your head and press hands forward.

  3. Press hands frimly on the hips and bow slightly forward.

  4. During shower raise your one arm and use the fingers of the oher hand to palpate the breast in a circular fashion from periphery to the nipple for unusual lump or mass under the skin.

  5. Gently squeeze the nipple and look for any discharge. Do similar examination on the other side.

  6. The steps 4 and 5 should be repeated in lying down position. In this position the breasts are flattened and make it easier to palpate them.