What are the CPT4 (Current Procedural Terminology, 4th edition) codes for a patient undergoing a right skin-sparing mastectomy and a left nipple-sparing mastectomy, along with a right sentinel lymph node biopsy and the insertion of a tissue expander for breast reconstruction?

CPT-4 Coding for Bilateral Mastectomy with Reconstruction and Sentinel Node Biopsy

For this complex bilateral procedure, you should report the following CPT codes: 19301-RT (right skin-sparing mastectomy), 19301-LT (left nipple-sparing mastectomy), 38525-RT (right sentinel lymph node biopsy), and 19357 (bilateral tissue expander insertion).

Primary Procedure Codes

Mastectomy Codes

• Right skin-sparing mastectomy: CPT 19301-RT (Modified radical mastectomy, including axillary lymph nodes, with or without pectoralis minor muscle, but excluding pectoralis major muscle)

  • Skin-sparing mastectomy involves removal of breast parenchyma including the nipple-areola complex while preserving most of the original skin envelope 1
  • This procedure should be performed by experienced breast surgery teams working in coordinated, multidisciplinary fashion 1, 2

• Left nipple-sparing mastectomy: CPT 19301-LT (same code, different modifier)

  • Nipple-sparing mastectomy preserves both the skin envelope and nipple-areola complex 1
  • This approach is appropriate for carefully selected patients with early-stage, biologically favorable cancers located >2cm from the nipple 2, 3
  • Mandatory intraoperative nipple margin assessment is required when considering nipple-sparing procedures 1, 2

Sentinel Lymph Node Biopsy

• Right sentinel lymph node biopsy: CPT 38525-RT (Biopsy or excision of lymph node(s); open, deep axillary node(s))
  • Sentinel lymph node biopsy concomitant with mastectomy is a safe option with SLN identification rates of 98% 4
  • This can be performed safely at the time of mastectomy with immediate reconstruction, though proper planning is needed 4

Reconstruction Code

• Bilateral tissue expander insertion: CPT 19357 (Tissue expander placement in breast reconstruction, including subsequent expansion)
  • This code covers the initial placement of tissue expanders bilaterally 1
  • Reconstruction with implants can be performed through initial placement of a subpectoral expander implant followed by gradual expansion 1
  • The National Comprehensive Cancer Network recommends that reconstruction typically involves either implant-based procedures or autologous tissue transplantation 2

Important Coding Considerations

Laterality Modifiers

• Use -RT modifier for right-sided procedures (mastectomy and sentinel node biopsy) 4
• Use -LT modifier for left-sided procedures (mastectomy only in this case)
• The tissue expander code 19357 is inherently bilateral and does not require modifiers when placing expanders on both sides

Common Pitfalls to Avoid

• Do not separately code the skin-sparing or nipple-sparing technique - these are included in the mastectomy code 19301 and represent surgical technique variations rather than separate procedures 1, 3
• Do not use 19303 (simple mastectomy) - this code is inappropriate when performing skin-sparing or nipple-sparing techniques with lymph node assessment 1
• Ensure proper documentation of the different mastectomy techniques (skin-sparing vs. nipple-sparing) on each side, as this affects oncologic appropriateness even though the CPT code remains the same 2, 3
• Document the sentinel node technique and number of nodes removed - average removal is 2.4 nodes per patient, and this documentation supports medical necessity 4

Reconstruction Timing Documentation

• Document that this is immediate reconstruction performed at the same time as mastectomy under the same anesthetic 1
• Immediate reconstruction is appropriate for the vast majority of mastectomy patients, with inflammatory breast cancer being the primary contraindication 2, 5
• Note that reconstruction involves a staged approach requiring multiple procedures, so this is only the first stage 1, 2

Clinical Context for Coding Support

• The number of axillary lymph nodes removed impacts complication rates - removal of >4 nodes confers greater risk of seroma and expander loss 6
• Nipple-sparing mastectomy shows oncologically safe outcomes with low cancer recurrence rates (0-3.7% in the nipple-areola complex) 3, 7
• Direct-to-implant reconstruction is emerging as preferred when breast skin envelope is sufficiently perfused, though tissue expander approach remains most common 7