Nevus-Associated versus de novo Melanoma: Do They Have Different Characteristics and Prognoses?

Aim: The aim of this study was to determine if nevus-associated melanoma differs in characteristics and prognosis from de novo melanoma. Patients and Methods: The study included 118 melanoma patients. Clinical findings were retrospectively evaluated. For histopathological parameters, HE sections were reexamined. The differentiation between de novo and nevus- associated melanoma was based on the histopathological evidence of a precursor nevus. In addition, all analyses were repeated in all cases in which nevus-associated melanoma was defined based on patient anamnesis. Results: Among all patients, 28 (23.7%) had nevus-associated melanoma. Nevus-associated melanoma was most commonly located on the extremities (50%), followed by the trunk (25%), whereas de novo melanoma was most commonly located in the head and neck region (32.2%), followed by the acral region (31.1%). Other clinical findings and histopathological parameters did not differ significantly between the two groups (p > 0.05). The findings remained consistent following the repeated analysis of all cases in which nevus-associated melanoma was defined based on patient anamnesis. Conclusions: Nevus-associated melanoma was most commonly located on the extremities and the trunk, whereas de novo melanoma was most commonly located in the head and neck and the acral region. Furthermore, nevus-associated melanoma was similar to de novo melanoma in terms of prognosis and other disease characteristics. (C) 2015 S. Karger AG, Basel