Pathology Unit, St. Anna Hospital (ASST Lariana), Como, Italy.
Department of Pathology, Azienda Ospedaliera SS. Antonio e Biagio e Cesare Arrigo di Alessandria, Alessandria, Italy; Department of Pathology, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy.
Pathol Res Pract. 2023 Nov;251:154915. doi: 10.1016/j.prp.2023.154915. Epub 2023 Oct 29.
Melanocytic lesions have always represented a diagnostic challenge for surgical pathologists. According to the literature, PRAME showed great promise as an immunohistochemical tool in the distinction between benign and malignant melanocytic lesions. In the present study, we retrospectively analyzed 137 thicker (Breslow > 1 mm) primary cutaneous melanomas with the aim to better understand the utility of PRAME immunohistochemistry in daily practice and also to investigate if PRAME could represent a prognostic biomarker for cutaneous melanomas. PRAME immunohistochemistry was performed in all melanomas and in the metastases with antibodies to PRAME (dilution 1:1000, clone Ab219650) on an automated immunostainer (Ventana Benchmark Ultra) using a brown chromogen (DAB). We found that melanomas (59.1%) show diffuse PRAME expression (score 4 +). 99 (72.3%) primary cutaneous melanoma had no relapse during the follow-up. Of this group of melanomas, 61/99 (61.6%) were diffusely positive for PRAME. 38 (27.7%) primary cutaneous melanoma had relapses. Of this group, 28/36 (77.7%) were diffusely positive. We did not find any statistical correlation between diffuse PRAME expression and the presence of driver mutation in BRAF gene (p = 0.927), NRAS gene (p = 0.496) or either of the two (p = 0.138). We did not find a prognostic significance of diffuse PRAME expression for relapse (p = 0.462) or survival rate (p = 0.245). The prognostic value of PRAME has been only reported in mucosal, uveal and cutaneous thin melanomas. Here, we show statistical analyses on PRAME expression for melanoma with Breslow > 1 mm based on survival rate and long-term follow-up. According to our results, PRAME is a useful immunohistochemical ancillary tool in daily practice diagnosis of melanocytic lesions.
黑素细胞病变一直是外科病理学家诊断的难题。根据文献报道，PRAME 作为一种免疫组织化学工具，在区分良性和恶性黑素细胞病变方面显示出巨大的潜力。在本研究中，我们回顾性分析了 137 例较厚（Breslow>1mm）原发性皮肤黑色素瘤，旨在更好地了解 PRAME 免疫组化在日常实践中的应用价值，并探讨 PRAME 是否可以作为皮肤黑色素瘤的预后生物标志物。我们使用针对 PRAME（稀释度 1:1000，克隆 Ab219650）的抗体在自动免疫组化仪（Ventana Benchmark Ultra）上进行 PRAME 免疫组化染色，使用棕色显色剂（DAB）。我们发现黑色素瘤（59.1%）表现为弥漫性 PRAME 表达（评分 4+）。99 例（72.3%）原发性皮肤黑色素瘤在随访期间无复发。在这组黑色素瘤中，61/99（61.6%）弥漫性 PRAME 阳性。38 例（27.7%）原发性皮肤黑色素瘤复发。在这组中，28/36（77.7%）弥漫性 PRAME 阳性。我们没有发现弥漫性 PRAME 表达与 BRAF 基因突变（p=0.927）、NRAS 基因突变（p=0.496）或两者都不存在之间存在任何统计学相关性（p=0.138）。我们没有发现弥漫性 PRAME 表达与复发（p=0.462）或生存率（p=0.245）之间存在预后意义。PRAME 的预后价值仅在黏膜、葡萄膜和皮肤薄黑色素瘤中报道过。在这里，我们根据生存率和长期随访结果，对 Breslow>1mm 的黑色素瘤的 PRAME 表达进行了统计学分析。根据我们的结果，PRAME 是一种在日常实践中诊断黑素细胞病变的有用的免疫组织化学辅助工具。
