The recent WHO classification of skin tumors has underscored the importance of acknowledging intermediate grade melanocytic proliferations. A multistep acquisition of oncogenic events drives the progressive transformation of nevi into melanomas. The various pathways described are modulated by the initial oncogenic drivers that define the common, blue, and Spitz nevi groups. Intermediate lesions are most often the result of a clonal evolution within such nevi. Based on this established classification, we have suggested for each pathway a practical diagnostic approach, benefiting from the recently developed molecular tools, both in the setting of general pathology labs and expert centers. Moreover, recommendations regarding the re-excision and clinical follow-up are given to support decision-making in multidisciplinary tumor boards.

最近世界卫生组织对皮肤肿瘤的分类强调了承认中级黑素细胞增殖的重要性。致癌事件的多步获取驱动痣逐渐转化为黑色素瘤。所描述的各种途径由定义普通、蓝色和 Spitz 痣组的初始致癌驱动因素调节。中间病变通常是这种痣内克隆进化的结果。基于这个既定的分类，我们为每个途径建议了一种实用的诊断方法，受益于最近开发的分子工具，无论是在普通病理实验室还是专家中心的设置中。此外，还给出了关于再次切除和临床随访的建议，以支持多学科肿瘤委员会的决策。