Mohs micrographic surgery histopathology concordance.

ABSTRACT

BACKGROUND: The low recurrence rate and tissue-sparing benefit associated with Mohs micrographic surgery (MMS) requires accurate interpretation of frozen sections by the MMS surgeon. OBJECTIVE: We sought to assess concordance between dermatopathologists and MMS surgeons when reporting cutaneous malignancy in the MMS setting. METHODS: This study is a retrospective analysis of 1156 slides submitted during 10 years as part of a pre-existing randomized, blinded, quality assurance protocol. Slides were read by one of 5 dermatopathologists and represent cases from 3 MMS surgeons and 5 MMS fellows. Agreement or disagreement was recorded. RESULTS: Of the 1156 slides, 32 slides (2.8%) were disparate. Aside from differences regarding intraepidermal neoplasia, the concordance rate was 99.7%. LIMITATIONS: This study represents data collected at a single institution in the United States alone. CONCLUSION: There was statistically significant concordance between MMS surgeons and dermatopathologists in frozen section interpretation in the MMS setting. Discordance was primarily related to the interpretation of in situ malignancy.