Melanoma Clinical Margin Width – New SSDI for 2023

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Registry Partners

As facilities move into abstracting 2023 cases, there have been some exciting and positive changes with abstracting melanoma skin primaries specifically with surgical coding and the addition of a new SSDI – clinical margin width. 

The margin width for wide local excision (WLE) for melanoma is based on the Breslow thickness of the primary tumor. Per the American College of Surgeons Optimal Resources for Cancer Care-2020 Standards Standard 5.5 Local Excision for Primary Cutaneous Melanoma, the clinical margin width for wide local excision of invasive melanoma should be 

  • 1 cm for melanomas <1 mm thick
  • 1 to 2 cm for invasive melanomas 1 to 2 mm thick
  • 2 cm for invasive melanomas >2 mm thick
  • The clinical margin width for wide local excision of a melanoma in situ should be at least 5 mm

The new SSDI clinical margin width is required for CoC and SEER for 2023 diagnosis year. CTRs may leave this data item blank for cases diagnosed 2018 through 2022. This new SSDI describes the margins from the wide excision of a melanoma primary. The margin width is measured by the surgeon prior to the procedure and is measured in centimeters from the edge of the lesion or previous excision scar to the peripheral margin of the specimen. The priority is given to the operative note followed by a physician statement in the medical record. CTRs are to document the stated margin in centimeters and include the decimal point. 


0.5 cm = 0.5, 2.0 cm = 2.0, XX.1 for 10 cms or greater, XX.9 for Mohs procedure

The SSDI coding instructions and notes instruct the CTR in coding

Do Do Not
Code the peripheral margins from the operative report from a wide excisionUse the pathology report
Code the clinical margin width from the procedure with the largest margin IF multiple wide excisionsUse deep margin
Use XX.9 if Mohs procedureAdd margins together

The SSDI manual is the primary resource for complete rules and instructions. Check out Appendix M in the STORE 2023 manual for helpful case studies on coding melanoma cases!