Department of Anatomical Pathology, Douglass Hanly Moir Pathology, Macquarie Park, 2113, Australia; Cancer Diagnosis and Pathology Group, Kolling Institute of Medical Research, Royal North Shore Hospital, 2065, Australia; Faculty of Medicine, University of Sydney, 2065, Australia.
Department of Anatomical Pathology, Douglass Hanly Moir Pathology, Macquarie Park, 2113, Australia; Department of Clinical Medicine, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, 2113, Australia.
Hum Pathol. 2022 Jun;124:1-13. doi: 10.1016/j.humpath.2022.03.001. Epub 2022 Mar 17.
ERG overexpression has been linked to acute myeloid leukemia/myeloid sarcoma (MS). The aim of our study was to identify the frequency of ERG immunohistochemical (IHC) expression in MS (n = 21), blastic plasmacytoid dendritic cell neoplasms (BPDCNs; n = 8), extramedullary hematopoiesis (EMH: n = 9), normal and pathological bone marrow trephine biopsies (BM-TBs, n = 18), and the marrow component of adrenal myelolipomas (n = 15). ERG-positive and ERG-negative immunostains were identified in 68.4% and 31.5% of patients with MS, respectively (2-3+, 20% to >90% of cells), while all BPDCNs were negative. ERG + MS cases were over-represented in those of myeloid differentiation when compared with those of pure monocytic/monoblastic differentiation, which were ERG-negative (P=<0.001). ERG was expressed in immature myeloid cells in 100% of cases of EMH, BM-TBs, and adrenal myelolipomas (n = 42), resulting in a sensitivity of 100% in this setting. Negative ERG immunostaining was also 100% sensitive in discriminating cells of erythroid lineage, mature lymphocytes, and reactive or neoplastic plasma cells. Variable IHC expression occurred in megakaryocytes and neutrophils. In summary, we confirmed a high frequency of ERG expression in MS and identified ubiquitous expression in non-neoplastic immature myeloid lineage cells. We believe that ERG can be of diagnostic utility to identify neoplastic and reactive myeloid infiltrates in peripheral tissues and possibly as an ancillary marker to exclude the diagnosis of BPDCNs when positive. However, ERG must be used in an antibody panel, as expression is not limited to myeloid cells.
ERG 过表达与急性髓系白血病/髓肉瘤（MS）有关。我们的研究目的是确定 MS（n=21）、原始浆细胞样树突状细胞瘤（BPDCN；n=8）、髓外造血（EMH：n=9）、正常和病理性骨髓活检（BM-TB，n=18）以及肾上腺髓性脂肪瘤骨髓成分（n=15）中 ERG 免疫组织化学（IHC）表达的频率。MS 中分别有 68.4%和 31.5%的患者 ERG 阳性和 ERG 阴性免疫染色（2-3+，20%至>90%的细胞），而所有 BPDCN 均为阴性。与纯单核/单核样分化相比，髓系分化的 MS 病例中 ERG+MS 病例更为常见，而 ERG 阴性（P=<0.001）。在 100%的 EMH、BM-TB 和肾上腺髓性脂肪瘤病例中（n=42），ERG 在幼稚髓细胞中表达，因此在这种情况下具有 100%的敏感性。阴性 ERG 免疫染色在区分红系细胞、成熟淋巴细胞和反应性或肿瘤浆细胞方面也具有 100%的敏感性。巨核细胞和中性粒细胞的 IHC 表达存在变异性。总之，我们证实了 MS 中 ERG 表达的高频率，并确定了非肿瘤性幼稚髓系细胞中的普遍表达。我们认为 ERG 可用于识别外周组织中的肿瘤性和反应性髓系浸润，并且当阳性时可能作为排除 BPDCNs 诊断的辅助标志物。但是，必须在抗体组中使用 ERG，因为表达不仅限于髓细胞。
