General Information (cont'd)...    

In general, the main role of the breast is the production of milk during the breast feeding period. From a simple anatomical point of view it is a skin-covered organ consisting of fat, supporting connective tissue and the mammary gland The mammary gland consists of 15 to 20 sections called lobes, that are built of smaller elements called lobules, which end in dozens of tiny bulbs. These bulbs are drained by minute ducts which subsequently are drained to gradually increasing in size calibre ducts. These ducts open at the milk sinus located under the nipple which is located in the center of the dark area of the breast called the areola. All these gland elements form the mammary gland, are supported by connective tissue and are surrounded and separated by fat. The end buds of the mammary gland consist of a layer of cubical secretion cells on top of cells which have the ability to contract and are responsible for milk expulsion during breast feeding.

Small and larger ducts have an inner lining of a single layer of cells. Regular cells divide in an orderly fashion to replace those, which have aged and died. However, sometimes glandular and ductal cells begin to divide without control, forming disorderly groups of cells that at a specific stage of atypical growth are called carcinoma in situ, which subsequently if expanded can lead to a malignancy called invasive breast cancer (lump or tumour).
 

A malignant tumour can grow locally, within the breast, but sometimes its cells can spread and travel via lymphatic vessels to lymph nodes or other parts of body (the liver, lungs, bones) either by lymphatic or blood vessels, forming new tumours, called metastases.