Pathology, Security Forces Hospital, La Marsa, Tunisia.
Pathology, Institut Salah-Azaiz, Tunis, Tunisia.
J Immunoassay Immunochem. 2021 Jul 4;42(4):370-379. doi: 10.1080/15321819.2020.1870132. Epub 2021 Jan 14.
Langerhans cell histiocytosis (LCH) is a rare disorder of unknown etiopathogenesis. Diagnosis is based on the identification of CD1a positive histiocytic infiltrate. Activation of the mitogen-activated-protein-kinase (MAPK) is constantly observed in LCH and therefore downstream markers such as cyclin D1 may be a useful marker for LCH. The aim of this study was to investigate the expression of cyclin D1 in LCH. We assessed the immunohistochemical expression of cyclin D1 (clone SP4-R) in series of 16 cases of confirmed LCH. Expression of Cyclin D1 was scored as weak, moderate, and strong nuclear staining and results were interpreted by two pathologists. The percentage of positivity was assessed. The mean age of patients was 13.7 years old with a male to female ratio of 1:3. The most common involved site was bone (n = 9; 56,3%), followed by lymph node (n = 5; 31,2%) and skin (n = 2; 12,5%). All cases showed nuclear staining for cyclin D1 with variable intensity. It was assessed moderate in 43,8% (n = 7) and strong in 56,2% (n = 9). The percentage of positive cells was >50% in 13 cases and <50% in 3 cases. Our results have shown that all cases of Langerhans cell histiocytosis from various sites express cyclin D1. This finding may be attributed to MAPK pathway activation that has been described in LCH. Otherwise, cyclin D1 is not significantly expressed in reactive Langerhans cell proliferations. Therefore, cyclin D1 immunohistochemistry may be useful as a diagnostic marker and in excluding non-neoplastic mimics of LCH.
朗格汉斯细胞组织细胞增生症（LCH）是一种病因不明的罕见疾病。诊断基于识别 CD1a 阳性组织细胞浸润。在 LCH 中经常观察到丝裂原活化蛋白激酶（MAPK）的激活，因此细胞周期蛋白 D1 等下游标志物可能是 LCH 的有用标志物。本研究旨在研究 LCH 中细胞周期蛋白 D1 的表达。我们评估了 16 例确诊为 LCH 的病例中细胞周期蛋白 D1（克隆 SP4-R）的免疫组织化学表达。细胞周期蛋白 D1 的表达评分分为弱阳性、中度和强阳性核染色，由两名病理学家进行解读。评估阳性百分比。患者的平均年龄为 13.7 岁，男女比例为 1:3。最常见的受累部位是骨骼（n=9；56.3%），其次是淋巴结（n=5；31.2%）和皮肤（n=2；12.5%）。所有病例均显示细胞周期蛋白 D1 核染色，强度不同。43.8%（n=7）为中度，56.2%（n=9）为强阳性。13 例的阳性细胞百分比>50%，3 例<50%。我们的结果表明，来自不同部位的所有朗格汉斯细胞组织细胞增生症病例均表达细胞周期蛋白 D1。这一发现可能归因于已在 LCH 中描述的 MAPK 途径激活。否则，细胞周期蛋白 D1 在反应性朗格汉斯细胞增殖中不显著表达。因此，细胞周期蛋白 D1 免疫组化可能是一种有用的诊断标志物，有助于排除 LCH 的非肿瘤性模拟物。
