Breast Cancer ·

02 — Mastectomy and Breast Reconstruction

BREAST CANCER SERIES

02 — Mastectomy and Breast Reconstruction

A scientific overview of surgical removal of breast tissue, chest-wall anatomy, and modern reconstructive strategies

Mastectomy and breast reconstruction are two distinct but often coordinated components of breast-cancer surgery. A mastectomy removes breast tissue containing, or at risk of containing, cancer, while reconstruction aims to restore the external form of the breast using an implant, the patient's own tissue, or a combination of both. Reconstruction does not recreate the original mammary gland or its milk-producing function. (Cancer.gov)

01 — The Anatomy Being Operated On

The adult breast is composed primarily of adipose tissue, fibrous connective tissue, mammary glands and ducts, positioned over the pectoralis major muscle and anterior chest wall. The glandular component is organized into lobes, which contain smaller lobules connected to ducts that converge toward the nipple.

Lymphatic drainage is clinically important because breast cancer cells can migrate through lymphatic vessels to regional lymph nodes, particularly the axillary lymph nodes. Depending on the cancer, surgeons may therefore perform a sentinel lymph-node biopsy or axillary lymph-node dissection in addition to the mastectomy. (Cancer.gov)

Anatomical cross-section

Skin → subcutaneous fat → mammary tissue → pectoral fascia → pectoralis major muscle → ribs/intercostal tissues

The breast itself is therefore not a single solid organ. It is a three-dimensional tissue architecture containing epithelial, stromal, adipose, vascular, lymphatic and neural components.

This anatomy explains an important consequence of mastectomy: removing the breast removes not only malignant tissue but also structures responsible for normal breast sensation and, when the nipple–areolar complex is removed, the visible external anatomy.

02 — What Is a Mastectomy?

A mastectomy is surgical removal of the entire breast rather than only the tumour and a surrounding margin, as occurs in breast-conserving surgery.

Mastectomy may be recommended when the tumour is large relative to breast size, there are multiple tumour sites, inflammatory breast cancer is present, previous radiation limits further breast-conserving treatment, cancer remains after previous lumpectomy, or genetic/familial risk makes risk-reducing mastectomy appropriate. (Cancer.gov)

Principal types

Total/simple mastectomy
Removes the breast, including the mammary tissue and usually the nipple–areolar complex. Lymph-node surgery may be performed separately.

Skin-sparing mastectomy
Removes the breast tissue and usually the nipple–areolar complex while preserving most of the breast skin envelope. This is generally performed with immediate reconstruction. (Cancer.gov)

Nipple-sparing mastectomy
Removes the underlying breast tissue while preserving the skin, nipple and areola when oncologically appropriate. Tumour location, involvement of the nipple region, breast anatomy and other clinical factors determine eligibility. (Cancer.gov)

Modified radical mastectomy
Removes the breast together with axillary lymph nodes. It is used selectively, particularly when nodal disease requires more extensive surgical treatment.

Radical mastectomy
Historically involved removal of the breast, axillary nodes and chest-wall muscles. It is now rarely performed, because less extensive procedures generally provide equivalent cancer control without the same degree of tissue destruction. (Cancer.gov)

03 — What Happens to the Chest Wall?

A mastectomy does not normally mean removal of the pectoralis major muscle. In contemporary surgery, the goal is to remove the breast tissue while preserving as much healthy chest-wall structure, skin and vascular supply as oncologically safe.

After breast tissue is removed, the surgeon is left with a mastectomy skin envelope overlying the chest wall. That envelope can subsequently support an implant or reconstructed tissue.

The exact residual anatomy depends on the type of mastectomy, tumour location, previous surgery, radiation and reconstruction strategy.

04 — Immediate vs Delayed Reconstruction

Reconstruction can occur at different points in the cancer-treatment pathway.

Immediate reconstruction

The reconstruction begins during the same operation as the mastectomy.

The principal advantage is preservation of the breast skin envelope and creation of the breast mound before the patient awakens from surgery. It can also reduce the period during which the chest has no breast contour.

Delayed reconstruction

Reconstruction occurs after the mastectomy, sometimes months or years later.

This can be advantageous when additional cancer treatment—particularly radiation—is expected or when the patient wants time to recover and decide whether reconstruction is appropriate.

Radiation can alter skin and soft tissue, increasing the complexity of reconstruction and the risk of complications. Treatment sequencing therefore needs to be planned jointly by the breast surgical, plastic surgical, medical oncology and radiation oncology teams. (Cancer.gov)

05 — Implant-Based Reconstruction

Implant reconstruction uses a saline- or silicone-filled breast implant to recreate breast volume.

A common approach is two-stage reconstruction:

Mastectomy → tissue expander → gradual expansion → permanent implant

A tissue expander is a temporary device placed beneath the mastectomy skin, sometimes with additional supporting material. It is gradually filled to stretch the surrounding tissue before being exchanged for a permanent implant. (Cancer.gov)

In selected patients, a direct-to-implant reconstruction can be performed during the mastectomy itself.

Biological principle

The implant supplies volume, while the patient's remaining skin and surrounding soft tissues provide the external envelope.

This makes implant reconstruction less dependent on another donor site but also means that the reconstructed breast is fundamentally different from native breast tissue.

Potential complications include:

infection
seroma or hematoma
wound-healing problems
implant rupture
capsular contracture
implant malposition
reconstructive failure

Implants are not lifetime devices; the probability of complications and additional surgery increases over time. (Cancer.gov)

06 — Autologous Reconstruction: Using the Patient's Own Tissue

Autologous reconstruction uses tissue from another anatomical region to construct the breast mound.

The transferred tissue may contain:

skin
subcutaneous fat
blood vessels
sometimes muscle

The tissue is called a flap.

Common donor sites include the abdomen, back, buttocks and thighs. (Cancer.gov)

The DIEP flap

The deep inferior epigastric perforator (DIEP) flap is particularly important in modern microsurgical reconstruction.

Skin and subcutaneous fat are harvested from the lower abdomen while the major rectus abdominis muscle is preserved. The flap's blood vessels are disconnected from their original circulation and microsurgically connected to recipient vessels in the chest.

In simplified form:

Abdominal skin + fat → perforating vessels → microsurgical transfer → chest blood vessels → reconstructed breast

Unlike a traditional TRAM flap, a DIEP flap is designed to preserve the rectus abdominis muscle. (Cancer.gov)

Other flap techniques include TRAM, SIEA/SIEP, PAP, TUG, SGAP, IGAP and latissimus dorsi flaps, selected according to anatomy, previous surgery, available tissue and reconstructive objectives. (Cancer.gov)

07 — Why Blood Vessels Matter

Reconstructive tissue is living tissue. It requires an adequate blood supply to survive.

In a pedicled flap, the tissue remains attached to its original vascular supply while being repositioned.

In a free flap, the tissue is completely detached and transferred to the chest. Microsurgery is then used to connect the flap's artery and vein to recipient vessels.

This vascular connection allows:

arterial blood → oxygen and nutrients → flap tissue

and

venous drainage → removal of deoxygenated blood and metabolic products.

Failure of adequate perfusion can result in flap ischemia or necrosis, making vascular monitoring an essential component of free-flap reconstruction. (Cancer.gov)

08 — Reconstruction and Sensation

One of the most underestimated biological consequences of mastectomy is loss of sensation.

Breast sensation is supplied by cutaneous branches of thoracic intercostal nerves. When breast tissue and associated nerves are removed or disrupted, numbness is common.

Some sensation may gradually return through neural regeneration, but recovery is variable and may remain incomplete. (Cancer.gov)

Modern reconstructive surgery increasingly incorporates sensory nerve reconstruction, in which a nerve associated with the transferred flap can be connected to an available chest-wall sensory nerve.

The objective is reinnervation of the reconstructed tissue, potentially improving protective and tactile sensation over time. (American Cancer Society)

This represents an important transition in reconstructive surgery: the goal is no longer simply to reproduce the shape of a breast, but increasingly to restore aspects of its biological function and sensory integration.

09 — Nipple and Areola Reconstruction

If the nipple–areolar complex is removed, reconstruction can occur after the breast mound has stabilized.

Options include:

Surgical nipple reconstruction — local skin is shaped to create a projecting nipple.

Medical tattooing — pigmentation recreates the visual appearance of the areola and can create highly realistic three-dimensional optical effects.

Nipple prostheses — an external option for people who do not want additional surgery.

When oncologically appropriate, a nipple-sparing mastectomy can preserve the patient's original nipple and areola. (Cancer.gov)

10 — The Option of Going Flat

Reconstruction is optional.

Some patients choose an aesthetic flat closure, in which excess skin and tissue are removed and the chest wall is deliberately contoured to create a smooth, balanced surface.

Others use an external breast prosthesis.

There is no biologically or oncologically universal requirement that a breast removed by mastectomy must be replaced. The appropriate choice depends on the individual's cancer treatment, anatomy, health, preferences and goals. (Cancer.gov)

11 — Reconstruction Is Not a Single Operation

Breast reconstruction frequently occurs as a process rather than one operation.

A reconstruction pathway may involve:

Mastectomy
↓
Tissue expansion or flap/implant reconstruction
↓
Healing and tissue maturation
↓
Revision or fat grafting if required
↓
Nipple–areolar reconstruction or tattooing
↓
Final contour and symmetry

Fat grafting may be used to correct contour irregularities or asymmetry by transferring processed adipose tissue from another part of the body. (Cancer.gov)

12 — The Biology of Healing

Following mastectomy and reconstruction, the body enters a coordinated wound-healing response.

Hemostasis
Blood vessels constrict and clotting prevents excessive blood loss.

Inflammation
Immune cells remove damaged tissue and microorganisms and release signaling molecules.

Proliferation
Fibroblasts produce extracellular matrix while endothelial cells participate in new-vessel formation. Epithelial cells migrate across the wound.

Remodeling
Collagen and extracellular matrix are reorganized over months, progressively changing scar strength and appearance.

For tissue-engineered and reconstructive medicine, this biological sequence is fundamental: vascularization, extracellular-matrix organization, inflammation and innervation all influence the long-term performance of reconstructed tissue.

13 — Major Considerations When Choosing Reconstruction

The reconstructive strategy is individualized. Important variables include:

Factor	Why it matters
Cancer location and stage	Determines what tissue must be removed
Mastectomy type	Determines the available skin and nipple envelope
Radiation therapy	Can alter skin quality and healing
Body composition	Determines available donor tissue
Previous surgery	May eliminate potential flap donor sites
Smoking, diabetes and obesity	Can increase surgical complications
Desired breast size	Influences implant vs flap suitability
Recovery tolerance	Flap surgery is generally more extensive
Sensation goals	May influence consideration of nerve reconstruction
Personal preference	Reconstruction is elective and highly individualized

(Cancer.gov)

14 — Mastectomy Is Cancer Surgery; Reconstruction Is Reconstructive Biology

The distinction is important.

Mastectomy is designed primarily to achieve oncologic control.

Reconstruction is designed to restore form—and increasingly, selected aspects of function.

The reconstructed breast does not contain the original mammary glandular system, so it does not reproduce normal milk production or the complete biological physiology of the native breast.

Nevertheless, modern reconstruction can restore:

three-dimensional contour → soft-tissue volume → symmetry → skin coverage → nipple–areolar appearance → and, in selected procedures, sensation.

The field is therefore moving beyond cosmetic replacement toward increasingly sophisticated restoration of anatomy, vascularity, sensation and tissue quality.

Conclusion

Mastectomy removes the breast tissue required to treat or reduce the risk of breast cancer, while reconstruction addresses the anatomical consequences of that removal. Modern techniques range from implant-based reconstruction and tissue expansion to microsurgical transfer of the patient's own vascularized tissue, including muscle-sparing procedures such as the DIEP flap.

The most significant scientific advance is perhaps the shift from simply rebuilding shape toward rebuilding living tissue. Vascular anastomosis, adipose tissue transfer, extracellular-matrix remodeling and sensory nerve reconstruction demonstrate how contemporary breast reconstruction increasingly intersects with regenerative medicine, microsurgery and tissue engineering.

For patients who choose reconstruction, the objective is not merely to create an image of a breast. It is to construct a stable, vascularized, integrated soft-tissue structure that can participate as naturally as possible in the anatomy of the chest.

Scientific References

National Cancer Institute. Mastectomy. National Institutes of Health. (Cancer.gov)
National Cancer Institute. Breast Reconstruction After Mastectomy. National Institutes of Health. (Cancer.gov)
National Cancer Institute. Breast Cancer Treatment (PDQ®). National Institutes of Health. (Cancer.gov)
American Cancer Society. Breast Reconstruction Options. (American Cancer Society)
American Cancer Society. Breast Reconstruction Using Implants. (American Cancer Society)
American Cancer Society. Breast Reconstruction Using Your Own Tissue: Flap Procedures. (American Cancer Society)
American Society of Plastic Surgeons. Breast Reconstruction. (American Society of Plastic Surgeons)
National Cancer Institute Visuals Online. Breast Illustration. Public-domain anatomical illustration. (visuals-prod-cf10.ha.nci.nih.gov)

URIBHO | Breast Cancer Series — Article 02
Scientific education • Surgical anatomy • Reconstructive medicine