Pathologic Upstaging of Cutaneous Melanoma After Mohs Micrographic Surgery

BACKGROUND Mohs micrographic surgery (MMS) is used for melanoma in situ (MIS) and thin invasive melanomas, particularly on the head and neck, during which a debulk section is typically prepared. Tumor upstaging occurs if the debulking specimen meets criteria for an increased tumor (T) stage per the American Joint Committee on Cancer 8th edition compared with the initial biopsy. Upstaging can alter survival and recurrence outcomes, resulting in increased patient morbidity and mortality. OBJECTIVE To determine the rate of cutaneous melanoma upstaging during MMS. MATERIALS AND METHODS A multicenter study was performed. Information from electronic medical records from 3 dermatologic surgeons performing MMS for cutaneous melanoma were logged from January 1, 2017 to December 31, 2021. Deidentified information regarding patient demographics and tumor characteristics was recorded. RESULTS Three-hundred and ten cases of cutaneous melanoma treated with MMS were identified. 2.3% of cases were upstaged, ranging from T1a to T3a. No significant risk factors for upstaging were identified. CONCLUSION Our data demonstrate a lower rate of cutaneous melanoma upstaging during MMS than the current literature. Differences may be accounted for because of differing patient populations, cutaneous melanoma detection at an earlier clinical stage, and evolving melanoma histologic criteria.