title: Two cutaneous malignant melanomas at the same anatomic site: a case report with molecular evaluation.
abstract: Patients who have had malignant melanoma are at an increased risk of developing a second primary melanoma compared with the general population risk of developing a first melanoma. Many of these second primary melanomas occur at a similar anatomic site as the first lesion. Determining whether a second lesion is indeed a separate primary vs. a metastasis or locoregional recurrence can be very difficult histologically. We report the case of a patient who developed a second melanoma, 2 years after the initial diagnosis, within 3 cm of the site of the original lesion. Because of distinct histomorphologic features, the second lesion was favored to be a separate primary. However, because of the nearly identical anatomic location, molecular testing for loss of heterozygosity and BRAF mutation was performed to help further make this distinction. The first lesion was found to have loss of heterozygosity and a BRAF mutation that were not present in the second lesion. While these tests cannot elucidate the true molecular origin of these lesions, they provide a useful clinical tool to assess whether a second lesion should be treated as a recurrence or as a separate lesion with unique biologic potential.
authors.affiliation: Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA. edingerjt@upmc.edu
authors.forename: James T
authors.initials: JT
authors.lastname: Edinger
authors.forename: Arash
authors.initials: A
authors.lastname: Radfar
authors.forename: Drazen M
authors.initials: DM
authors.lastname: Jukic
mesh_terms: D000368:Aged; D003937:Diagnosis, Differential; D006801:Humans; D019656:Loss of Heterozygosity; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008545:Melanoma / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D009154:Mutation; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D016609:Neoplasms, Second Primary / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D016133:Polymerase Chain Reaction; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000235:genetics / Q000473:pathology* / Q000601:surgery
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf