In Stage 0 melanoma, the malignant cells are confined to the upper layer of the skin (epidermis or Level I). This means that the cancer cells are only in the outer layer of the skin (epidermis) and have not grown any deeper. The term for this is in situ, (which means ‘in place’ in Latin) or Level 1. There is no evidence the cancer has spread to the lymph nodes or distant sites.
