35 惡性黑色素細胞瘤（malignant melanoma）最重要的預後因子是：

腫瘤厚度（tumor thickness）

發生部位（anatomic site）

腫瘤周邊有無淋巴球浸潤（tumor-infiltrating lymphocytes）

分裂指數（mitotic rate）

it is thickness

answer anatomic site is wrong , yes it is sun exposure to prone to dev melanoma but if already develop melanoma, it is not really a prognosticating factor.