Abstract：
BACKGROUND: Preferentially expressed antigen in melanoma (PRAME) has been introduced as a new melanoma marker and potential target for immunotherapy. While PRAME immunohistochemistry (IHC) is well documented in surgical pathology, similar data in cytology are limited. Metastatic melanoma is frequently diagnosed via cytology samples in which IHC plays an important role. We aimed to accordingly evaluate the performance of PRAME IHC in diagnosing metastatic melanoma in cytology samples relative to other commonly used melanoma markers.
METHODS: The study included 156 archival cytology cases, of which 93 were melanoma cases and 63 nonmelanoma cases (controls). All cases underwent PRAME IHC staining on cell blocks. Nuclear staining of PRAME was evaluated using a quantitative and qualitative scale. Other melanocytic IHC stain results (SOX10, S-100, Melan-A, and HMB45) were also documented.
RESULTS: PRAME was detected in tumor cells in 86% of melanoma cases, which was significantly lower than SOX10 (100%) (p < .01), and similar to HMB45 (84%) and Melan-A (82%). S-100 had the lowest sensitivity of 71%. In comparison to other types of melanomas, spindle cell melanoma exhibited higher negativity for PRAME IHC (4/10 = 40%). PRAME was also expressed in some nonmelanocytic malignancies including carcinoma (5/22 = 23%), sarcoma (5/15 = 33%), and hematologic malignancies (1/9 = 11%). Overall, PRAME showed a sensitivity of 86%, specificity of 82%, positive predictive value of 70%, and negative predictive value of 92% for metastatic melanoma.
CONCLUSIONS: PRAME is a useful marker for the diagnosis of melanoma in cytology material, but it is less sensitive than SOX10. PRAME is also expressed in other nonmelanocytic tumors which limits its specificity.
METHODS: The study included 156 archival cytology cases, of which 93 were melanoma cases and 63 nonmelanoma cases (controls). All cases underwent PRAME IHC staining on cell blocks. Nuclear staining of PRAME was evaluated using a quantitative and qualitative scale. Other melanocytic IHC stain results (SOX10, S-100, Melan-A, and HMB45) were also documented.
RESULTS: PRAME was detected in tumor cells in 86% of melanoma cases, which was significantly lower than SOX10 (100%) (p < .01), and similar to HMB45 (84%) and Melan-A (82%). S-100 had the lowest sensitivity of 71%. In comparison to other types of melanomas, spindle cell melanoma exhibited higher negativity for PRAME IHC (4/10 = 40%). PRAME was also expressed in some nonmelanocytic malignancies including carcinoma (5/22 = 23%), sarcoma (5/15 = 33%), and hematologic malignancies (1/9 = 11%). Overall, PRAME showed a sensitivity of 86%, specificity of 82%, positive predictive value of 70%, and negative predictive value of 92% for metastatic melanoma.
CONCLUSIONS: PRAME is a useful marker for the diagnosis of melanoma in cytology material, but it is less sensitive than SOX10. PRAME is also expressed in other nonmelanocytic tumors which limits its specificity.
摘要：
背景:黑素瘤中优先表达的抗原(PRAME)已被引入作为新的黑素瘤标志物和免疫疗法的潜在靶标。虽然PRAME免疫组织化学（IHC）在手术病理学中有很好的记录，类似的细胞学数据有限.经常通过细胞学样本诊断转移性黑色素瘤，其中IHC起着重要作用。我们旨在相应地评估PRAMEIHC相对于其他常用的黑色素瘤标志物在细胞学样品中诊断转移性黑色素瘤的性能。
方法：该研究包括156例档案细胞学病例，其中93例黑色素瘤病例和63例非黑色素瘤病例（对照）。所有病例均对细胞块进行PRAMEIHC染色。使用定量和定性量表评估PRAME的核染色。其他黑色素细胞免疫组化染色结果（SOX10，S-100，Melan-A，和HMB45）也有记录。
结果：在86％的黑色素瘤病例的肿瘤细胞中检测到PRAME，显著低于SOX10(100%)(p<.01)，与HMB45（84％）和Melan-A（82％）相似。S-100的灵敏度最低，为71%。与其他类型的黑色素瘤相比，梭形细胞黑色素瘤对PRAMEIHC表现出更高的阴性(4/10=40%)。PRAME也在一些非黑色素细胞恶性肿瘤中表达，包括癌（5/22=23%），肉瘤（5/15=33%），和血液系统恶性肿瘤（1/9=11％）。总的来说,PRAME显示出86%的灵敏度，82%的特异性，阳性预测值为70%，转移性黑色素瘤的阴性预测值为92%。
结论：PRAME是细胞学材料中诊断黑色素瘤的有用标记，但它不如SOX10敏感。PRAME也在其他非黑色素细胞肿瘤中表达，这限制了其特异性。
方法：该研究包括156例档案细胞学病例，其中93例黑色素瘤病例和63例非黑色素瘤病例（对照）。所有病例均对细胞块进行PRAMEIHC染色。使用定量和定性量表评估PRAME的核染色。其他黑色素细胞免疫组化染色结果（SOX10，S-100，Melan-A，和HMB45）也有记录。
结果：在86％的黑色素瘤病例的肿瘤细胞中检测到PRAME，显著低于SOX10(100%)(p<.01)，与HMB45（84％）和Melan-A（82％）相似。S-100的灵敏度最低，为71%。与其他类型的黑色素瘤相比，梭形细胞黑色素瘤对PRAMEIHC表现出更高的阴性(4/10=40%)。PRAME也在一些非黑色素细胞恶性肿瘤中表达，包括癌（5/22=23%），肉瘤（5/15=33%），和血液系统恶性肿瘤（1/9=11％）。总的来说,PRAME显示出86%的灵敏度，82%的特异性，阳性预测值为70%，转移性黑色素瘤的阴性预测值为92%。
结论：PRAME是细胞学材料中诊断黑色素瘤的有用标记，但它不如SOX10敏感。PRAME也在其他非黑色素细胞肿瘤中表达，这限制了其特异性。
