Department of Pathology, UVA Health System, Charlottesville, VA.
Lab Bacchi, Botucatu, SP, Brazil.
Am J Surg Pathol. 2020 Oct;44(10):1353-1366. doi: 10.1097/PAS.0000000000001524.
It is becoming increasingly important to obtain detailed diagnostic information on small-volume tissue biopsies, such as core needle biopsies. This is particularly crucial in the workup and diagnosis of classic Hodgkin lymphoma (CHL) and other morphologically similar lymphomas such as T-cell/histiocyte-rich large B-cell lymphoma (THRLBL), where small-volume lymph node biopsies often represent the frontline tissue source, and the differential diagnosis includes a reactive process. Immunohistochemical markers could be helpful to differentiate CHL from reactive lymph node changes (RLN) in this setting. The use of programmed cell death-1 (PD-1) and its ligand (PD-L1) immunohistochemistry has historically focused on prognostic and therapeutic value when evaluating CHL. However, the present study seeks to determine the diagnostic utility of these markers in core needle biopsies of CHL (25), THRLBL (3), and RLN (31). The cases of CHL and THRLBL were previously diagnosed and confirmed with standard immunohistochemistry, allowing the utility of PD-1 and PD-L1 to be tested in this setting. Different PD-1 and PD-L1 expression patterns were observed between the reactive process of RLN and the malignant lymphomas (CHL and THRLBL). CHL cases overall showed the greatest expression of PD-L1 within the malignant Reed-Sternberg cell population, with 40% of CHL cases exhibiting >50% PD-L1 expression. This degree of PD-L1 expression was not seen in the lymphocytic cell population of any RLN (P<0.001). Conversely, CHL cases showed an overall lower expression of PD-1, as 96% of CHLs had <5% PD-1 expression in Reed-Sternberg cells compared with only 10% expression within the lymphocytic population of RLN (P<0.001). THRLBL cases followed a similar trend to CHL. These results demonstrate that upfront PD-1 and PD-L1 immunohistochemistry can aid in the diagnosis of CHL in small-volume tissue biopsies.
越来越需要获取小体积组织活检（如芯针活检）的详细诊断信息。这在经典霍奇金淋巴瘤（CHL）和其他形态相似的淋巴瘤（如 T 细胞/组织细胞丰富的大 B 细胞淋巴瘤（THRLBL））的检查和诊断中尤为关键，在这些疾病中，小体积淋巴结活检通常是一线组织来源，鉴别诊断包括反应性过程。免疫组化标志物有助于在这种情况下将 CHL 与反应性淋巴结变化（RLN）区分开来。程序性细胞死亡受体-1（PD-1）及其配体（PD-L1）的免疫组化检测在评估 CHL 时，其历史作用主要集中在预后和治疗价值上。然而，本研究旨在确定这些标志物在 CHL（25 例）、THRLBL（3 例）和 RLN（31 例）芯针活检中的诊断效用。CHL 和 THRLBL 病例以前通过标准免疫组化进行诊断和确认，允许在这种情况下检测 PD-1 和 PD-L1 的效用。RLN 的反应性过程和恶性淋巴瘤（CHL 和 THRLBL）之间观察到不同的 PD-1 和 PD-L1 表达模式。CHL 病例的恶性 Reed-Sternberg 细胞群体中 PD-L1 表达最高，40%的 CHL 病例表现出 >50%的 PD-L1 表达。任何 RLN 的淋巴细胞群中均未观察到这种程度的 PD-L1 表达（P<0.001）。相反，CHL 病例 PD-1 的表达总体较低，因为 96%的 CHL 病例的 Reed-Sternberg 细胞中 PD-1 表达<5%，而 RLN 的淋巴细胞群中仅为 10%（P<0.001）。THRLBL 病例的趋势与 CHL 相似。这些结果表明， upfront PD-1 和 PD-L1 免疫组化可辅助小体积组织活检中 CHL 的诊断。
