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

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 purse-string 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.