Concordance Between a Mohs Micrographic Surgeon and Dermatopathologist on Margin Status for Melanoma In Situ and the Role of Immunohistochemical Stains

Abstract

Background: Few studies have examined the concordance between Mohs surgeons and dermatopathologists' interpretation of margin status during Mohs micrographic surgery (MMS) for melanoma in situ (MIS).

Objective: The objectives of this study were to determine the concordance between a Mohs surgeon and dermatopathologist on margin status for MIS and to analyze the role of immunohistochemical stains during Mohs surgery.

Materials and methods: This was a prospective study at 1 academic center of patients undergoing Mohs surgery for MIS. The Mohs surgeon and dermatopathologist independently examined the margins and completed surveys on the usefulness of H&E and immunohistochemical stains in each case. Six-year follow-up data on tumor recurrence and metastasis were collected.

Results: The surgeon and dermatopathologist agreed on margin status in 95% of cases (95% confidence interval: 0.84-0.99). The dermatopathologist found H&E alone to be the most useful stain for the first stage of MMS, while the Mohs surgeon found the combination of H&E and SOX10 most useful. This study is limited by the use of only 2 physicians.

Conclusion: There was a high concordance between the Mohs surgeon and dermatopathologist on MIS margin status. Immunohistochemical stains were more useful for the Mohs surgeon.