摘要目的:探讨黑色素瘤优先表达抗原（PRAME）免疫组织化学染色在良恶性皮肤黑色素细胞肿瘤鉴别中的应用价值。方法:收集北京大学第三医院病理科2018年10月至2020年12月间常规及会诊确诊的黑色素瘤病例59例（皮肤原发性黑色素瘤50例，转移性黑色素瘤9例），黑色素细胞痣48例（普通型痣40例，非典型性痣8例），进行PRAME免疫组织化学染色，比较黑色素瘤和黑色素细胞痣中PRAME免疫组织化学表达的差异。结果:皮肤原发性黑色素瘤患者50例，男性23例，女性27例；年龄33~87岁（平均年龄62.4岁，中位年龄64.5岁）。转移性黑色素瘤9例，男性7例，女性2例；年龄40~82岁（平均年龄64岁，中位年龄65岁）。26例（26/50，52.0%）皮肤原发性黑色素瘤和4例（4/9）转移性黑色素瘤均表现为PRAME弥漫阳性；40例（40/40，100%）普通型痣和8例（8/8）非典型性痣均表现为PRAME阴性。黑色素瘤组中PRAME弥漫阳性病例数所占比例显著高于黑色素细胞痣组（ P<0.05）。本组病例中，PRAME鉴别良恶性皮肤原发性黑色素细胞肿瘤的灵敏度和特异度分别为52.0%和100%。 结论:PRAME免疫组织化学染色在黑色素瘤和黑色素细胞痣中表达的差异，可作为良恶性皮肤黑色素细胞肿瘤鉴别的辅助诊断手段。

abstractsObjective:To investigate the diagnostic value of preferentially expressed antigen in melanoma (PRAME) in differential diagnosis of benign and malignant cutaneous melanocytic lesions.Methods:Fifty-nine cases of melanoma (50 cases of skin primary melanoma, and 9 cases of metastatic melanoma) and 48 cases of melanocytic nevus (40 cases of common nevus and 8 cases of dysplastic nevus) were subject to PRAME immunohistochemistry staining.The difference of PRAME expression between melanoma and melanocytic nevus was analyzed.Results:Among the 50 patients with primary cutaneous melanoma, there were 23 males and 27 females ranging in age from 33 to 87 years (average age 62.4 years, median age 64.5 years). Among the 9 metastatic melanoma there were 7 males and 2 females ranging in age from 40 to 82 years (average age 64 years, median age 65 years). Twenty-six cases (26/50, 52.0%) of cutaneous primary melanoma and 4 cases (4/9) of metastatic melanoma showed diffuse positive PRAME staining. 40 cases (40/40, 100%) of common nevus and 8 (8/8) cases of dysplastic nevus were PRAME negative. Compared with melanocytic nevus group, the melanoma group included more cases with diffuse positive PRAME staining ( P<0.05). The sensitivity and specificity of using PRAME to differentiate primary cutaneous melanoma from melanocytic nevus in the cohort is 52.0% and 100%. Conclusions:There is a significant difference in the expression of PRAME between melanoma and melanocytic nevus.Thus, PRAME can be used as an auxiliary diagnostic tool for differentiating benign from malignant cutaneous lesions.