There are three types of mastectomy, but the third type is now rarely carried out:
Local mastectomy: removal of the breast tissue and the fascia overlying the muscle underneath
Modified radical mastectomy: removal of the breast tissue, the fascia and the lymph nodes under the arm
Radical mastectomy: rarely done. Removal of the breast tissue, the lymph nodes and the underlying muscle and fascia
Fascia is connective tissue which forms membrane-type layers which are of differing thickness in all regions of the body. It surrounds the softer or more delicate organs and it is divided into superficial fascia (immediately beneath the skin) and deep fascia (which forms sheaths for the muscles). The fascia removed in a mastectomy is deep fascia surrounding the muscles underlying and around the breast.
How is a mastectomy carried out?
The type of incision into the skin depends on the size of the tumour, the type of tumour and whether or not breast reconstruction is going to be carried out immediately.
The breast tissue is pealed from the skin. As much possible of the skin and underlying fat are preserved in cases where a reconstruction is planned. In most cases the nipple and areola are removed along with the breast tissue. Nipple-sparing surgery is only done in exceptional cases. The breast is then removed whole, with the covering of the muscle underneath. If a modified radical mastectomy is done then the lymph nodes are removed through the same incision.
What happens in the axilla (armpit)?
The lymph nodes in the axilla will nearly always have to be removed if they are felt to be enlarged when the woman is first examined. This is carried out using a technique called an axillary dissection.
What is an axillary dissection?
It is removal of some or all of the lymph nodes in the axilla:
The incision may be as part of the mastectomy incision or may be through a separate incision. It may be done at the same time as a wide local excision.
If there are no enlarged lymph nodes on examination then there are different approaches:
The lymph nodes may be left
A sentinel lymph node biopsy (link to the go-to box) may be performed
A limited operation may be performed in which some of the lymph nodes are removed
Reviewed by Dr David Eedes, Oncologist, December 2011