Total Mastectomy ± Sentinel Lymph Node Biopsy

Total (simple) mastectomy removes the entire breast including the nipple-areolar complex (NAC) and the pectoral fascia, without axillary content. Sentinel lymph node biopsy is added for invasive disease and select DCIS. For contralateral prophylactic decisions and adjuvant therapy discussions, see the breast topic review. For the composite operation with axillary content, see modified radical mastectomy.

Procedure Snapshot

• Indications:
  • DCIS — large, multi-quadrant, or contraindication to BCT.
  • Multicentric invasive cancer (different quadrants — BCT contraindicated).
  • Persistent positive margins after reasonable re-excision.
  • Inflammatory breast cancer after neoadjuvant chemotherapy → MRM (not BCT) because inflammatory disease requires ALND.
  • Prior chest / breast radiation (repeat radiation not tolerated).
  • Prophylactic — BRCA1/2, high penetrance familial risk, patient choice for symmetry.
  • Paget’s disease of the nipple — mastectomy including NAC, with SLN.
  • Male breast cancer — MRM typically (small volume, thin breast, high NAC involvement).
  • Patient preference for mastectomy over BCT for early cancer.
• Expected duration: 90–150 min for simple mastectomy; +30–45 min for SLNB.
• Positioning: Supine, ipsilateral arm on padded board abducted 90°. Prep from clavicle to costal margin, midline to posterior axillary line.
• Special instruments: Electrocautery with Bovie extender, right-angle retractors (Deaver, malleable), fine tissue forceps, closed-suction drains (JP × 1–2), gamma probe / blue dye / magnetic probe for SLNB.
• Prep: Cefazolin within 60 min. If reconstruction planned, coordinate with plastics: prepectoral direct-to-implant, tissue expander, autologous flap (DIEP, TRAM, LD).
• Reconstruction planning: Simple mastectomy is completed the same day as immediate reconstruction if planned. Skin-sparing and nipple-sparing variants are technique-driven and require oncologic candidacy (no skin involvement, no NAC involvement, appropriate NAC-to-tumor distance).

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Step Workflow — Total (Simple) Mastectomy

1. Marking + SLNB Injection
   • Draw the incision on the awake patient — elliptical, oriented obliquely from lateral-inferior to medial-superior, encompassing NAC and biopsy scar. Wise-pattern for reconstruction planning.
   • Inject dye for SLNB peri-areolar at the start of the case (Tc-99m already given in nuclear medicine 2–24 hr preop).
2. Elliptical Skin Incision + Flap Elevation
   • Incise skin along markings; carry down through subcutaneous tissue with cautery.
   • Raise skin flaps at the plane just superficial to the breast parenchyma, preserving the subdermal plexus (~ 5–8 mm subcutaneous fat depth). Not too thin (flap necrosis) and not too thick (residual breast tissue).
   • Boundaries:
     • Superior: infraclavicular soft tissue (just below the clavicle).
     • Medial: lateral border of the sternum.
     • Lateral: anterior border of the latissimus dorsi.
     • Inferior: inframammary fold / rectus sheath.
3. Deep Dissection off the Pectoralis Major
   • Elevate the entire breast off the pectoralis major, taking the pectoral fascia with the specimen (natural anatomic plane; oncologic principle).
   • Work medial to lateral. Cauterize perforating vessels — internal mammary perforators medially will bleed generously; suture-ligate the larger ones with 3-0 silk or clip and cut.
   • Preserve the pectoralis major muscle — this distinguishes total mastectomy from the historic Halsted radical mastectomy.
4. Axillary Tail (Tail of Spence)
   • Dissect the axillary tail off the axillary contents. If NOT doing SLNB or ALND at the same operation, stop at the clavipectoral fascia — do not enter the axillary fat pad.
   • If doing SLNB, transition to the sentinel node step (below).
5. SLNB (if invasive cancer or select DCIS)
   • Continue through the same superior-lateral incision or add a small separate axillary incision (some surgeons prefer contiguous mastectomy + axillary access via one wound).
   • Divide the clavipectoral fascia; identify hot / blue nodes with the gamma probe / visual dye.
   • Remove all hot (> 10% of hottest ex-vivo), blue, and clinically suspicious nodes — usually 1–4.
   • Send for pathology.
6. Specimen Handling
   • Remove the specimen en bloc; orient with a suture (a single stitch at the 12 o’clock skin edge is standard).
   • Confirm complete removal of breast tissue by palpation of the chest wall.
   • Weigh the specimen (some centers) and send to pathology.
7. Hemostasis, Drains, Closure
   • Meticulous hemostasis of the entire pocket — pectoralis fascia, axillary vessels if exposed, inframammary vessels.
   • Place JP drains — one along the mastectomy pocket. Two if performing axillary dissection.
   • Close skin in two layers: deep dermal 3-0 Vicryl; subcuticular 4-0 Monocryl or interrupted 3-0 nylon.
   • Bulky dressing; no pressure bra over the axillary drainage (seroma).

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Skin-Sparing / Nipple-Sparing Variants (parallel notes)

• Skin-sparing mastectomy (SSM): removes NAC, biopsy scar (if superficial), and breast tissue. Preserves the skin envelope. Enables immediate reconstruction with better cosmesis. Oncologically equivalent to total mastectomy for appropriate candidates.
• Nipple-sparing mastectomy (NSM):
  • Preserves NAC + skin envelope. Superior cosmesis.
  • Candidates: small tumors, tumor ≥ 2 cm from NAC (imaging + intraop nipple base biopsy on frozen), no NAC involvement, favorable breast size, no smoking (nipple necrosis risk).
  • Contraindications: NAC involvement, inflammatory cancer, prior radiation, high-grade DCIS extending to NAC.
  • Technique: inframammary or lateral radial incision; dissect breast tissue off the underside of the nipple (leave the terminal ducts on the NAC — this is the key oncologic step). Send nipple base tissue for frozen — positive → excise NAC.

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Rapid-Fire Questions

• Q: Difference between simple / total mastectomy and MRM? A: MRM = total mastectomy + level I–II ALND en bloc. Total (simple) removes breast and NAC but leaves the axilla alone.

• Q: What is preserved in a modern total mastectomy that was removed historically? A: The pectoralis major muscle — historic Halsted radical mastectomy removed it.

• Q: When do you take pectoral fascia? A: Always — natural anatomic plane, oncologic principle, no functional cost.

• Q: Do you need SLNB for DCIS? A: For lumpectomy DCIS — no (unless upstaging is likely). For mastectomy DCIS — yes, because up to 25% show occult invasion on final path and you can’t go back to sample the axilla once the breast is gone.

• Q: Absolute contraindications to nipple-sparing mastectomy? A: NAC involvement, inflammatory cancer, prior radiation, active smoking (relative but strong), high-grade DCIS extending to NAC.

• Q: Where does the mastectomy skin flap plane sit? A: Just superficial to the breast parenchyma, preserving the subdermal plexus (~ 5–8 mm subcutaneous fat).

• Q: Most common early complication of mastectomy? A: Seroma — nearly universal, drains manage it.

• Q: Skin flap necrosis rate? A: ~ 5–15%; higher with smoking, thin flaps, immediate reconstruction with tension, radiation.

• Q: Post-mastectomy radiation indications? A: T3 / T4 tumors, ≥ 4 positive nodes, positive margins, skin / chest wall involvement, internal mammary node involvement.

• Q: Male breast cancer — operation of choice? A: MRM — small breast volume, high NAC involvement, thin tissue plane. BCT rarely feasible.

• Q: Contralateral prophylactic mastectomy — who benefits? A: BRCA1/2, Li-Fraumeni, other high-penetrance syndromes. Non-genetic patients get modest ipsilateral recurrence benefit only; no OS benefit shown in prospective studies.

• Q: Post-op day 3 with sudden expanding swelling of the mastectomy site? A: Hematoma — return to OR.

• Q: Post-op day 7 with clear fluid weeping from the incision after drain removal? A: Seroma — aspirate serially; re-place drain if repeatedly recurring.

• Q: Post-op day 10 patient complains of sharp pain and firmness under the mastectomy skin flap? A: Consider Mondor’s-like superficial thrombophlebitis or fat necrosis — imaging + reassurance.

• Q: Immediate reconstruction options? A: Tissue expander (staged), direct-to-implant (single stage, prepectoral increasingly common), autologous (DIEP > TRAM; LD ± implant). Choice depends on radiation plans, patient anatomy, and preference.

• Q: Delay reconstruction after radiation — how long? A: Typically 6–12 months after completion of radiation to allow tissue recovery.

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Critical Anatomy

• Extent of the breast: clavicle superiorly, sternum medially, inframammary fold inferiorly, latissimus dorsi laterally. The axillary tail (of Spence) extends into the axilla.
• Layers (superficial to deep): skin → subcutaneous fat with subdermal plexus → superficial fascia → breast parenchyma → deep pectoral fascia → pectoralis major → clavipectoral fascia → axillary space or chest wall.
• Blood supply of the mastectomy flap:
  • Subdermal plexus — preserved by staying superficial to breast parenchyma.
  • Perforators from internal mammary (medial), lateral thoracic, thoracoacromial — all divided in mastectomy.
• Danger zones:
  • Skin flap ischemia if raised too thin.
  • Internal mammary perforators (medial third rib space) — brisk bleed.
  • Pleura on deep dissection over the pectoralis fascia — pneumothorax risk if fascia violated.
  • Long thoracic and thoracodorsal nerves if venturing into axilla (SLNB or ALND).
• NAC blood supply: predominantly subdermal + underlying deep breast perforators — NAC preservation depends on subdermal plexus + ductal branches from internal mammary. Smoking, prior radiation, and thin/tension closures compromise NAC viability.

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Informed Consent Highlights

• Risks:
  • Skin flap necrosis ~ 5–15% (higher with smoking, thin flaps, immediate reconstruction).
  • Seroma — nearly universal; manage with drains, aspiration.
  • Hematoma ~ 1–3%; expanding = return to OR.
  • SSI ~ 2–5%; higher with reconstruction.
  • Chronic pain / paresthesias — up to 20%; intercostobrachial numbness common if SLNB done.
  • Lymphedema if any axillary intervention (SLNB ~ 5%; ALND ~ 20–30%).
  • NAC necrosis ~ 5–10% for NSM; higher in smokers.
  • Cosmetic outcome — asymmetry, contour deformity, capsular contracture (with implant).
  • Phantom sensation in the breast — common.
  • Standard: bleeding, VTE, cardiopulmonary, death.
• Benefits: Oncologic control for candidates where BCT is inappropriate; symmetry surgery / risk reduction; option for immediate reconstruction.
• Alternatives:
  • Lumpectomy + SLNB + whole-breast radiation if BCT candidate.
  • Neoadjuvant chemotherapy to downstage locally advanced disease.
  • Endocrine therapy alone in older ER+ patients (NCCN allows in select > 70 y).
  • Prophylactic risk-reducing mastectomy deferred with high-intensity surveillance (mammogram + MRI) in BRCA carriers who elect to delay.

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Post-Op Considerations

• Disposition: Typically same-day or overnight; longer with reconstruction.
• Drains: JP drains stay in until output < 30 mL/day for 2 consecutive days (typically 7–14 days). Empty and record 3× daily.
• Diet / activity: Regular diet; light activity POD 0–1. No heavy lifting > 10 lb for 2 weeks; no vigorous shoulder ROM through the flap for 2 weeks (though gentle ROM day 1 to prevent frozen shoulder).
• Analgesia: Multimodal, opioid-sparing. TAP or PEC blocks for open procedures.
• Follow-up:
  • Wound check at 1–2 weeks; drain management.
  • Path review meeting (margins, node status, receptors, HER2, Oncotype / MammaPrint).
  • Reconstruction next steps if staged.
  • Med onc + rad onc referrals as indicated.
• Red flags:
  • Expanding hematoma → return to OR.
  • Flap discoloration, blistering → early flap necrosis; debride at bedside if superficial.
  • Wound dehiscence with expander / implant exposure → OR for washout + salvage vs explant.
• Lymphedema surveillance: For any patient who had axillary intervention, SOZO baseline preop with serial post-op measurements is standard at Baylor and increasingly the community standard (PREVENT trial: early L-Dex-triggered compression reduced chronic lymphedema from ~35% to ~7%).

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Clinical Pearls

• Draw the incision on the awake patient whenever possible — position matters for cosmesis and reconstruction planning.
• Keep flaps at the plane just superficial to breast parenchyma. Not too thin, not too thick.
• Always take the pectoral fascia.
• Preserve pectoralis major — no functional cost, distinguishes from Halsted radical.
• Coordinate with plastics before the case if reconstruction is planned — incision choice, flap orientation, and pocket handling all differ.
• Drains manage seroma. Universal after mastectomy.
• Consider PMRT indications before offering mastectomy — some patients still need radiation.
• NSM candidacy is oncologic, not just cosmetic — protect from decision drift.
• SOZO at baseline if the patient will have any axillary intervention.
• Never miss a nipple-base frozen on NSM — positive → excise the NAC same day.

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Related Case Preps

• Lumpectomy + SLNB — for candidates suitable for BCT.
• Axillary Lymph Node Dissection — if > 2 positive SLNs, ineligible for Z0011, clinically positive axilla, or as part of MRM.
• Modified Radical Mastectomy — total mastectomy + level I–II ALND en bloc.

Related Topic Reviews

• Breast — staging, screening, systemic therapy, ABSITE-level pearls.

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References

1. Fisher B, Anderson S, Bryant J, et al. Twenty-year follow-up of a randomized trial comparing total mastectomy, lumpectomy, and lumpectomy plus irradiation (NSABP B-06). NEJM. 2002; 347(16): 1233–1241.
2. Veronesi U, Cascinelli N, Mariani L, et al. Twenty-year follow-up of a randomized study comparing breast-conserving surgery with radical mastectomy (Milan). NEJM. 2002; 347(16): 1227–1232.
3. NCCN Clinical Practice Guidelines in Oncology — Breast Cancer. NCCN.org.
4. Ridner SH, Dietrich MS, Cowher MS, et al. A randomized trial evaluating bioimpedance spectroscopy versus tape measurement for the prevention of lymphedema following treatment for breast cancer (PREVENT). Ann Surg Oncol. 2019; 26(10): 3250–3259.
5. Recht A, Comen EA, Fine RE, et al. Postmastectomy radiotherapy: an ASCO/ASTRO/SSO focused guideline update. JCO. 2016; 34(36): 4431–4442.