目前还没有适合决策和普遍使用的皮肤鳞状细胞癌（cSCC）分期系统。专家有无意识地将临床情况的异质性简化为几个相关组以推动他们的治疗决策。因此，我们使用专家对真实病例进行无监督聚类来生成 cSCC 的操作分类，这种方法在基底细胞癌中取得了成功。生成一致且可操作的 cSCC 分类。对 248 例被认为困难的 cSCC 病例进行无监督独立聚类-治疗。来自不同专业的 18 位国际专家将这些病例分类为他们认为对管理有用的同类集群，每个集群都可以自由选择集群标准。使用相似矩阵、K 均值方法和平均轮廓方法分析聚类之间的收敛和发散。使用数学模型来寻找最佳的共识聚类。派生分类的可操作性在 23 名新从业者身上得到了验证。尽管临床病例存在高度异质性，但仍观察到了数学共识。它最好的表示方式是分为五个集群，这似乎是后验描述不同的临床场景。新从业者和 18 名专家之间的病例分配具有良好的一致性（94%），这表明了这种分类的适用性。纳入了另一组易于治疗的鳞状细胞癌，最终分为六组：易于治疗/由于肿瘤和/或患者特征而治疗复杂/多发/局部晚期/区域疾病/内脏转移鉴于专家对病例进行无指导直观聚类的收敛性的方法，这种新的分类与临床实践相关。它不与分期系统竞争，但它们可以相互补充，无论目标是在肿瘤委员会中选择最佳治疗方法还是设计同质试验组。© 2024 作者。约翰·威利出版的欧洲皮肤病学和性病学会杂志

There is currently no staging system for cutaneous squamous cell carcinoma (cSCC) that is adapted to decision-making and universally used. Experts have unconscious ability to simplify the heterogeneity of clinical situations into a few relevant groups to drive their therapeutic decisions. Therefore, we have used unsupervised clustering of real cases by experts to generate an operational classification of cSCCs, an approach that was successful for basal cell carcinomas.To generate a consensual and operational classification of cSCCs.Unsupervised independent clustering of 248 cases of cSCCs considered difficult-to-treat. Eighteen international experts from different specialties classified these cases into what they considered homogeneous clusters useful for management, each with freedom regarding clustering criteria. Convergences and divergences between clustering were analysed using a similarity matrix, the K-mean approach and the average silhouette method. Mathematical modelling was used to look for the best consensual clustering. The operability of the derived classification was validated on 23 new practitioners.Despite the high heterogeneity of the clinical cases, a mathematical consensus was observed. It was best represented by a partition into five clusters, which appeared a posteriori to describe different clinical scenarios. Applicability of this classification was shown by a good concordance (94%) in the allocation of cases between the new practitioners and the 18 experts. An additional group of easy-to-treat cSCC was included, resulting in a six-group final classification: easy-to-treat/complex to treat due to tumour and/or patient characteristics/multiple/locally advanced/regional disease/visceral metastases.Given the methodology based on the convergence of unguided intuitive clustering of cases by experts, this new classification is relevant for clinical practice. It does not compete with staging systems, but they may complement each other, whether the objective is to select the best therapeutic approach in tumour boards or to design homogeneous groups for trials.© 2024 The Author(s). Journal of the European Academy of Dermatology and Venereology published by John Wiley & Sons Ltd on behalf of European Academy of Dermatology and Venereology.