中文摘要：

恶性黑素瘤是高度转移性肿瘤，对传统的治疗抵抗，黑素瘤的发生涉及遗传和环境因素。大多数黑素瘤为原发性，但部分黑素瘤从黑素细胞痣发展而来。以往认为，长期暴露于紫外线、皮肤黑素细胞逐渐积累致癌基因、肿瘤抑制基因发生突变导致了黑素细胞的增殖，并获得侵袭性和转移的能力，成为黑素瘤。另有假说认为，黑素瘤起源于毛囊外真皮黑素干细胞，紫外线诱导的突变可能会改变正常黑素干细胞自我更新、扩展和分化的过程，导致黑素瘤的形成。深入了解黑素瘤的发生机制，有利于寻求更好的治疗方案。

英文摘要：

Malignant melanoma is a highly metastatic cancer resistant to conventional therapy. The development of melanoma involves both genetic and environmental factors. Most cases of melanoma arise de novo, but some are known to arise in preexisting melanocytic nevi. The traditional hypothesis for melanoma development is that cutaneous melanocytes progressively accumulate mutations in oncogenes and tumor suppressor genes over a long time during exposure to ultraviolet, leading to uncontrolled proliferation of melanocytes with acquisition of invasive and metastatic properties, and finally resulting in melanoma formation. An alternative hypothesis is that melanoma begins in extrafollicular dermal melanocyte stem cells （MSCs）. Ultraviolet-induced mutations may cause the development of melanoma by altering the process of self-renewal, expansion and differentiation of normal MSCs. Understanding the mechanism underlying melanoma development is conducive to its treatment.