 Dr. Sanjay Sanyal, Professor, Department Chair. Considering the fact that breast cancer is of such overriding importance worldwide, there isn't enough dissections to demonstrate the surgical anatomy of the breast. So therefore we have decided to demonstrate the female breast and its intramamory architecture. This is the left breast and this is the right breast. The breast is a modified sweat gland which is located in the superficial fascia. And it has been removed from dissecting along the retromamory space, which is in contact with the pectoralis major fascia. The breast normally extends from the second to the sixth ribs and from the parasternal line to the anterior axillary line. Most of the breast is in the superficial fascia. However, this extension that we see here, this is the axillary tail of the breast. This goes through the axillary fascia and it continues into the fat of the axilla, which is shown here. And this can even normally be seen in a person. This portion is the one which is deep to the deep fascia. But the rest of the breast is superficial to the deep fascia. This is the region of the areola and the nipple. Under the skin which has been removed here is a thick layer of fat. And part of the fat has been kept here while a little bit of the fat has been removed to show that the breast tissue proper is covered by thin layer of fascia which we can see here. This is the capsule of the breast, this white portion that we see here. And this capsule of the breast, once we open this capsule, then we shall be able to see the actual breast tissue and I am going to open the capsule here. And this is what I am doing now. And once we open it, then we reach the actual breast tissue which I am going to show on this side. Now let's come to this side. Here we have ridden the skin. So we can see this is the nipple and around that there is the areola. And we have removed the subcutaneous fat. While removing the subcutaneous fat, we noticed that there were multiple ligaments connecting the lobules of the breast to the skin. And they were more prominent on the upper part of the breast and less on the lower part. And those ligaments are known as the suspensory ligaments of Cooper. And they are the ones which hold up the breast and also give the shape in the contour of the breast. So having removed the subcutaneous fat and the suspensory ligament, then we came across these lobules of the breast. And each lobule of the breast was again divided by multiple, indistinct, incomplete septae which we can see here. And they were divided into multiple spaces. And these are the multiple lobules that we can see. Inside each lobule, again we had considerable amount of fat which has been removed. After the fat has been removed, a little bit of the breast tissue was visible in this particular cadaver because she is an extremely old lady. Most of her breast tissue is a trophide. But inside these lobules are the breast tissue. I am cutting open one lobule. And once I split it open, we can see that each lobule is filled with fat. And once we clear the fat from here, then we will see a little bit of the breast tissue inside. This breast tissue is, that is, in the form of water known as mammary alveoli. During lactatic phase, the alveoli are encosed with milk. And other times, alveoli are collapsed. And multiple numbers of these alveoli, they together constitute a mammary lobule. And each of these lobules are drained by a lobular duct, all of which unite to form one lactiferous duct. And there will be 17 to 20 lactiferous ducts which will all converge in the region of the nipple, as we can see here. And they will all open onto the tip of the nipple. Just before they open into the nipple, they will have a small dilatation, which is not visible here. And that small dilatation is known as the lactiferous sinus. And that is the temporary storage of milk, which delivers milk to the baby's mouth when the baby is suckling. This is the full architecture of the breast. So therefore, the breast is covered by two levels of fat. One level of fat is under the skin, the subcutaneous fat. And once we have removed that, then we see each mammary lobule is also encased in fat. And the breast tissue is located within the mammary lobules. Now that brings me to an important clinical correlation pertaining to the breast that is with respect to breast cancer. Pathologically, we can have two different types of cancer. One is called the lobular carcinoma, the other is called the ductal carcinoma. Lobular carcinoma is less common, and that is only about 15 to 20% of all the carcinomas. And that is when it involves the mammary lobules itself. And the breast 80 or 85% of the cancers are the ductal cancer, which arises from the epithelium of the lactiferous ducts. And here again, we can have what is known as carcinoma in C2 and invasive carcinoma. If the cancer invades any of these lactiferous ducts, then it causes retraction. And when it pulls, it pulls the nipple inside, and that's what produces the retracted nipple. By the same mechanism, if a cancer involves one of the ligaments of Cooper, which are located here and which attach it to the underlying skin, then it can also pull on the ligament of Cooper and can produce dimpling of the skin. So dimpling of the skin, decent retraction of the nipple, these are all indications of invasive cancer. In the case of carcinoma breast, when we are doing a mastectomy, essentially we have to do something as shown here. We have to remove the breast from the retro mammary plane, and we have to excise not only the breast tissue, but we have also to excise the axillary tail. And in continuity, we have to remove the axillary fat and lymph nodes. That is called our block excision of the breast and the axillary tissue. If we were to make a separation between the two, then we can potentially leave cancer in between the two. So this is what is known as a modified radical mastectomy. Make sure you subscribe.