Prolonged evolution of a lentigo maligna

Lentigo maligna (LM) is a melanocytic lesion which is a potential precursor to melanoma and often has a prolonged intraepidermal growth phase before evolving into lentigo maligna melanoma (LMM). LM is also noted for its tendency to locally recur after treatment. We present a patient who had a persistent LM on her left cheek which, despite multiple excisions, persisted and transformed into a partially amelanotic LMM roughly three decades later. Our patient's course was also notable for this melanoma recurring at the edge of, and subsequently migrating into, a previously placed skin graft.