PRAME是一项新的免疫组化标志物，可以帮助诊断色素瘤性病变。广泛的PRAME阳性提示黑素瘤，而良性痣则是阴性或仅微弱的阳性。然而，PRAME的实际诊断准确性尚未得到充分证实。此外，一些研究表明，3+/50%阳性细胞的阈值在实践中可能比使用最广泛的切割值（4+/75%阳性细胞）更有用。因此，我们进行了系统回顾和诊断准确性荟萃分析，评估了PRAME在区分良性色素瘤性病变和黑色素瘤方面的敏感性、特异性、似然比和最优阈值。共纳入了26项研究进行荟萃分析。共分析了2915个色素瘤病变。PRAME阳性的最优阈值估计为3.11，在实践中相当于3+。通过SROC从3+阈值计算的敏感性和特异性分别为0.735（0.631-0.818）和0.915（0.834-0.958），而在4+切割值时分别为0.679（0.559-0.957）和0.957（0.908-0.981）。在子组分析中，斑状亚型组被最低的PRAME敏感性和诊断比比率所特征。我们的发现表明，PRAME免疫组化可能作为支持黑色素瘤诊断的辅助标志物。然而，在斑状新生物中，PRAME的准确性可能较低。我们的荟萃分析表明，3+/50%的阈值在实践中可能比4+/75%的切割值更有用，因为它在保持令人满意的特异性的同时，具有更高的敏感性。©2023 John Wiley & Sons Ltd.

PRAME is a novel immunohistochemical marker that aids the diagnosis of melanocytic lesions. Diffuse PRAME positivity suggests melanoma, whereas benign naevi are negative or only weakly positive. However, the factual diagnostic accuracy of PRAME is not well established. Moreover, some studies have suggested that the threshold of 3+/50% positive cells may be more useful in practice than the most widely used cut-off (4+/75% of positive cells). Hence, we performed a systematic review and diagnostic accuracy meta-analysis to evaluate sensitivity, specificity, likelihood ratios and optimal threshold for PRAME in distinguishing benign melanocytic proliferations from melanomas. Twenty-six studies were enrolled into the meta-analysis. A total of 2915 melanocytic lesions were analysed. The optimal threshold for PRAME positivity was estimated at 3.11, which translates into 3+ in practice. Sensitivity and specificity calculated from SROC at the 3+ threshold were 0.735 (0.631-0.818) and 0.915 (0.834-0.958), respectively, compared to 0.679 (0.559-0.957) and 0.957 (0.908-0.981) at the 4+ cut-off. In subgroup analysis, the spitzoid subgroup was characterised by the lowest sensitivity and diagnostic odds ratio of PRAME. Our findings indicate that PRAME immunohistochemistry may serve as an ancillary marker to support the diagnosis of melanoma. Nevertheless, the accuracy of PRAME may be lower in spitzoid neoplasms. Our meta-analysis suggests that the 3+/50% threshold might be more useful in practice than the 4+/75% cut-off, as it shows higher sensitivity with retained satisfactory specificity.© 2023 John Wiley & Sons Ltd.