Although the histological diagnosis of malignant melanoma is known to be difficult, this is even more true in the case of DM, as the morphological characteristics on the one hand and the loss of one or all of the markers of melanocytic differentiation (such as Melan-A, HMB-45, SOX-10 and MITF), poses major diagnostic challenges for, among others, high-grade sarcomas or carcinomas [7,8]. The gene discussed is SOX10; the disease is carcinoma.