Prior cosmetic treatment of lentigo maligna (LM) is not uncommon, and may delay diagnosis and obscure borders, resulting in wider surgical margins, a recent study found. Therefore, clinicians should consider a biopsy confirming the benign nature of equivocal lesions prior to cosmetic treatment. Researchers conducted a retrospective review of biopsy-proven LM presenting over a 10-year-period (2006–2015). Prior cosmetic treatment and biopsies were recorded and records were reviewed for demographic data, clinical characteristics, and surgical outcomes. They found:

• 37/503 (7.4%) patients with LM reported prior cosmetic therapy.
• Most (95%) were on the head and neck; mean size 1.9 cm.
• Most patients reported cryotherapy (73%), followed by laser (29.7%), topical bleaching agents (18.9%), and electrodessication, and/or curettage (5.3%).
• 10 patients (27%) received ≥2 modalities.
• 8 patients (21.6%) reported prior benign biopsies.
• 6 patients (16%) had invasive disease, 2 on initial biopsy and 4/34 (11.7%) upstaged upon excision.
• Average margin for clearance was 9.1 mm.