WEDNESDAY, Feb. 28, 2024 -- To achieve tumor clearance, melanoma in situ (MIS) on the head and neck often requires margins >5 mm, according to a study published online Jan. 20 in the Journal of the American Academy of Dermatology.

Jesalyn A. Tate, M.D., from the University of Texas Southwestern Medical Center in Dallas, and colleagues examined margins required for optimal cure rates with excision of MIS on the head and neck in a retrospective chart review performed on 846 MIS cases on the head and neck treated during a 126-month period.

The researchers found that 62 percent of the MIS cases were cleared with 5-mm margins. To achieve a 97 percent clearance rate, 15-mm margins were required. There was a significant difference observed in clearance rates between margin thresholds. There was a correlation seen for tumor location on the cheek and larger preoperative size with requiring >5-mm margins to achieve tumor clearance.

"This study demonstrates that MIS on the head and neck often requires margins >5 mm to achieve tumor clearance," the authors write. "When Mohs micrographic surgery is not possible, excision margins of ≥10 mm are likely necessary for head and neck tumors."