Rapid progression of lentigo maligna to deeply invasive lentigo maligna melanoma. Report of two cases.

Two patients had lesions of lentigo maligna that evolved into deeply invasive (level 4-5) lentigo maligna melanoma during a relatively short period (two years and four years, respectively). In both patients, the clinical impression of lentigo maligna had been difficult to confirm by histopathologic analysis until the invasive tumor had developed. Both patients were actively followed up during this period of evolution, with our intention of detecting any early changes suggestive of invasive melanoma. Since deep invasion developed despite close clinical supervision, a more aggressive approach to the treatment of lentigo maligna may be warranted.