The natural history of melanoma over time and the time that it takes for an atypical nevus to progress to melanoma are largely unknown. It is of crucial interest, in some cases, to establish whether we are dealing with a de novo melanoma or with a case of transformation of a preexisting melanocytic nevus. We report a case of a melanoma in situ that developed at the site of a pigmented skin lesion that had been photographically documented 10 years earlier in a high-risk female patient. Serial sections failed to demonstrate the presence of nevus remnants, thus raising the issue of the possibility that it was a 10-year-old de novo melanoma.
Carli P, Massi D, De Giorgi V, Mannone F, Giannotti B. A 10-Year-Old In Situ Melanoma?. Arch Dermatol. 2002;138(7):980-981. doi:10.1001/archderm.138.7.979