ABOUT ANATOMY OF BREAST
Anatomy of Breast and Axilla
Breast consists of the
- The breast parenchyma (Duct and lobules)
- Surrounding fatty tissue
Cancer spreads from the breast to its draining lymph nodes which are present in the armpit. These nodes are called ‘axillary lymph nodes’.
A cancer surgery for breast involves addressing both the breast and the draining axillary lymph nodes. So for the ease of understanding let’s divide the topic into two parts –
- Surgery for the breast
- Surgery for the axilla – Lymph nodes in the armpit
I – Surgery for the Breast
Wire Guided Excision
Sometimes there is no palpable swelling in the breast. However, on mammography, a suspicious area may be present.
So, right before the surgery, a wire is passed to mark this area, and wide excision of the entire area near the tip of the wire is done. This specimen is then sent for histopathology.
USG Guided Excision
Sometimes the lesion is not palpable. USG (Sonography) guided marking is done. Wide excision of the entire marked area is done.
Breast Conservative Surgery with Oncoplasty
Breast conservative surgery in two parts. Surgery of the breast and surgery of the axilla. Surgery of the axilla is explained later.
After surgery, all patients with breast conservation need to undergo Radiation therapy also. Breast conservative surgery, as the name suggests, involves wide excision of the breast lump. A plastic reconstructive procedure, otoplasty, may be added for better cosmesis.
When only the entire breast tissue (skin and underlying parenchyma) is excised without addressing the axillary nodes (armpit), the surgery is referred to as simple mastectomy.
Skin Sparing / Nipple Sparing Mastectomy
When a tumor does not involve the skin of the breast, the skin can be spared, thus this skin can be used in the reconstruction of the new breast.
When along with the skin, the nipple and areolar tissue can also be saved, then it is referred to as ‘Nipple Sparing Mastectomy’. We need to understand that, even when a nipple is spared, it is just for cosmesis. This nipple is insensate (no sensation) and cannot aid in lactation (breastfeeding is not possible).
Modified Radical Mastectomy
Sometimes it is not possible to conserve the breast due to:
i – Multiple tumors in the breast
ii – Large tumor size as compared to the breast size
iii – If a patient is unfit for further radiation therapy after breast conservation.
Modified Radical Mastectomy involves complete removal of the breast and addressing the axilla (armpit) at the same time. It involves the removal of overlying skin and the removal of the entire breast parenchyma along with the axillary nodes.
Latissimus Dorsi Flap Reconstruction
The Latissimus Dorsi (LD) muscle is located in the back just below the shoulder blade. This muscle helps in twisting movements such as swinging of racquet and also for supporting the shoulder to get up from the chair.
In LD flap reconstruction, a disc of skin, underlying fat, and the LD muscle is used for partial breast reconstruction. The flap is harvested from the back and passed under the skin to reach the breast. The donor area can be closed easily.
Whole breast reconstruction
As the name suggests, ‘Whole breast reconstruction is done after mastectomy. It can be done by Silicon implants or by free flaps.
Free flaps mean taking patients’ own tissue say from the abdomen (DIEP flap), thigh (ALT flap), etc.
II – Surgery of the Axilla (Armpit)
Sentinel Node biopsy
It’s a surgical procedure done to determine if cancer has spread to the axillary nodes. Over here a radiolabeled dye is injected in the breast or along with the tumor growth in the breast.
This dye is then traced to the first few draining nodes in the axilla, these nodes are excised and sent for evaluation. If these nodes are positive only then an axillary clearance is done.
When facilities for doing a sentinel node biopsy may not be available, then another equally efficient scientific procedure of axillary sampling is done.
Over here the lower part of axilla is dissected and all lymph nodes along with adjoining fat is sent for evaluation. If any positive node is found then axillary clearance is done. Scientific studies have proven axillary sampling to be equally competent as sentinel node biopsy.