Strategies for Reducing Final Surgical Defect Sizes in the Treatment of Lentigo Maligna

Abstract

BACKGROUND Lentigo maligna (LM) is associated with disproportionately high surgical morbidity. OBJECTIVE The authors report on 2 strategies to reduce the surgical morbidity associated with LM. METHODS Forty LM lesions were removed with excisional biopsies without margins and closed with pursestring sutures. Invasive cases underwent staged excisions with 10-mm margins. Cases without invasion were treated with neoadjuvant topical imiquimod 5% cream (5 d/wk × 8 weeks) followed by conservative staged excisions with 2-mm margins using radial sections stained with hematoxylin and eosin and immunostaining with Mart-1, with or without SOX10. RESULTS Invasion was detected in 12/40 (30%) of the excisional biopsy specimens (average depth 0.45 mm). No invasion was detected in 28/40 (70%). All 24 patients who completed neoadjuvant topical imiquimod 5% cream before staged excisions had negative first-stage margins at 2 mm. Compared with average published margins for LM, this represents a 71.4% reduction in the required margin and an average reduction in the final surgical defect by 74%. CONCLUSION LM treatment by excisional biopsies with a purse-string closure enables accurate tumor staging and contracts the tumor footprint to its minimal size. Subsequent neoadjuvant imiquimod followed by a conservative staged excision with 2-mm margins allows for removal of LM with decreased surgical morbidity.