Characteristics of Giant Nodular Melanomas in Special Locations: a Case Series and Review of the Literature

Abstract

Introduction: Nodular melanoma (NM) is a rare subtype of melanoma, responsible for more than 40% of melanoma deaths, characterized by rapid growth and high metastatic potential. Only a few case studies concerning the dermoscopic presentations of giant nodular melanoma have been reported so far. Objectives: The aim of the study was to assess dermoscopic features of giant nodular melanomas in special locations, along with their clinical and histopathologic aspects. Methods: Among 120 patients with histopathologically confirmed melanoma treated by the Skin Cancer and Melanoma Team between September 2020 and February 2021, we identified six patients with giant nodular melanoma in special locations. We retrospectively assessed the archived dermoscopic images to determine the dermoscopic features of these tumors. Results: The group consisted of six cases of giant melanoma in special locations, including the scalp (4/6) and the heel (2/6). The giant tumors were large in size (at least 5 cm in diameter). The most common dermoscopic structures in polarized light included asymmetric distribution of dermoscopic structures, the presence of structureless, multicolored zones (showing three or more colors), and the presence of white perpendicular lines or small, pink globules. Conclusions: It seems that there are no significant differences in dermoscopy between small and giant melanomas; however, further studies should be conducted on a larger scale.