RESUMO
INTRODUCTION: Dermoscopy is a complementary technique that has led to major advances in the diagnosis of pigmented skin lesions. The aim of this study was to describe the dermoscopic features of a series of melanomas and analyze the differences between melanomas in situ and invasive melanomas. MATERIAL AND METHODS: We retrospectively recorded epidemiological, clinical, histologic, and dermoscopic features of a series of 200 primary melanomas. We performed a descriptive and analytical study of the dermoscopic features identified. RESULTS: The mean age of the patients was 63 years and there was a similar distribution of male and female patients. The most common histologic subtypes were superficial spreading melanoma (62.5%) and lentigo maligna (25.5%); 67% of the melanomas had a Breslow thickness of less than 1mm and 24.5% were melanomas in situ. Overall,the most common global dermoscopic features were the multicomponent pattern (33.5%), the reticular pattern (18%), and the nonspecific pattern (15.5%). The most common local features were structureless homogeneous areas (67.5%), white-blue structures (58%), an atypical pigmented network (55.5%), and irregularly distributed dots and globules (44%). The following features were more common in invasive melanomas than in melanomas in situ: blue, gray, red and white colors, multicomponent and homogeneous patterns, dots and globules, blue-white structures, homogeneous areas, a blue-white veil, white shiny structures, a reverse pigment network, and milky-red areas. The reticular pattern was more common in melanomas in situ. DISCUSSION: The use of dermoscopy has contributed to the early diagnosis of melanoma. The most common dermoscopic features of melanoma are multiple structures and colors (multicomponent pattern), an atypical reticular pattern (with wide, irregular meshes), and an absence of distinguishing features (nonspecific pattern) associated with the presence of vascular structures. CONCLUSIONS: Dermoscopy facilitates the diagnosis of melanoma and could be useful for differentiating between melanoma in situ and invasive melanoma.