Melanoma arising in chronically photodamaged skin, especially on the head and neck, is often characterized by poorly defined clinical margins and unpredictable occult extension. Staged excision techniques have been described to treat these challenging melanomas.Objective
To investigate the local recurrence rates and margin to clearance end points using staged excision with comprehensive hematoxylin-eosin–stained permanent section margin control.Design, Setting, and Participants
In this observational cohort study performed from October 8, 1997, to December 31, 2006, with a median follow-up of 9.3 years, 806 patients with melanoma on the head and neck, where clinical occult extension is common, were studied at an academic medical center.Interventions
Staged excision with comprehensive hematoxylin-eosin–stained permanent section margin control commonly known as the square technique.Main Outcomes and Measures
Local recurrence rates and margin to clearance end points.Results
A total of 806 patients (276 women [34.2%]; 805 white [99.9%]) with a median age at the time of first staged excision procedure of 65 years (range, 20-94 years) participated in the study. The estimated local recurrence rates were 1.4% at 5 years, 1.8% at 7.5 years, and 2.2% at 10 years. For each 50-mm2 increase in the size of the clinical lesion, there was a 9% increase in the rate of local recurrence (hazard ratio, 1.09; 95% CI, 1.02-1.15; P = .02). The mean (SD) margin from lesion to clearance for melanoma in situ was 9.3 (5.1) mm compared with 13.7 (5.9) mm for invasive melanoma. For melanoma in situ, margins were clear after 5 mm or less in 232 excisions (41.1%) and after 10 mm or less in 420 excisions (74.5%). For invasive melanoma, margins were clear after 5 mm or less in 8 excisions (3.0%) and after 10 mm or less in 141 excisions (52.2%).Conclusions and Relevance
Staged excision with comprehensive permanent section margin control of melanomas arising in chronically sun-damaged skin on the head and neck has favorable recurrence rates when melanoma margins are difficult to assess, and recurrence rates are high with traditional techniques.