Risk factors associated with tumor upstaging in melanomas treated with Mohs micrographic surgery with melanocytic...

Mohs micrographic surgery with melanocytic immunohistochemistry (MMS-I) is increasingly utilized for special site melanoma treatment. Yet, frequency and risk factors associated with upstaging of all-stage cutaneous melanomas treated with MMS-I remain undefined.

Determine upstaging frequency and factors associated with tumor upstaging for all-stage melanomas treated with MMS-I.

In this retrospective, single-center case series, all cases of invasive and in situ melanoma treated with MMS-I between 2008 and 2018 were reviewed. Patient and tumor characteristics were recorded and compared between tumors that were and were not upstaged from their initial T stage.

Of the 962 melanoma MMS-I cases identified, 44 (4.6%) were upstaged, including 5.6% of in situ and 2.5% of invasive tumors. Risk factors for upstaging included lack of excisional intent at the time of initial biopsy (P < .01), nonlentigo maligna subtype (P = .03), female sex (P = .02), and initial in situ diagnosis (P = .03). Nonstatistically significant characteristics evaluated included patient age (P = .97), initial Breslow depth (P = .18), and biopsy type (P = .24).

Retrospective study design.

All-stage cutaneous melanomas treated with MMS-I are associated with low upstaging rates. Tumor upstaging is associated with lack of excisional intent, female sex, and in situ tumors.