Department of Pathology and Translational Genomics, Samsung Medical Center, Sungkyunkwan University, 06351, Seoul, Korea.
Section of Hematology-Oncology, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University, 06351, Seoul, Korea.
Hum Pathol. 2018 Mar;73:51-58. doi: 10.1016/j.humpath.2017.12.006. Epub 2017 Dec 16.
The cellular lineage of extranodal NK/T-cell lymphoma, nasal-type (ENKTL), is determined by expression of T-cell receptor (TR) or TR gene rearrangement. In ENKTL, from TR immunohistochemistry, it may often be difficult to decide whether TR-positive cells are tumor cells or not, especially when TR is expressed in a subset of tumor cells. To analyze TR expression pattern and TR rearrangement in T-lineage ENKTL, we performed double immunofluorescence staining for Epstein-Barr virus-encoded small RNAs (EBER)/T-cell receptor (TCR) βF1 and CD56/TCR βF1 in 12 cases of ENKTL that showed TCR βF1 expression in immunohistochemistry. TR gene rearrangement was analyzed using a commercial BIOMED-2 multiplex polymerase chain reaction system. Immunohistochemistry showed that all 12 cases expressed TCR βF1 in a wide range of infiltrating cells from 100% to <1%. Two of them expressed both TCR βF1 and TCR cγM1. EBER/TCR-βF1-positivity was confirmed in 10 cases by double staining. One case failed to show EBER/TCR-βF1-positive cells but showed a CD56/TCR βF1-positive result. Among 12 cases, 5 had poor-quality DNA, 3 of them showed no polymerase chain reaction product, and 2 cases showed nonspecific peak of low height. Five of 7 cases with good DNA quality demonstrated monoclonal TR gene rearrangement. Based on TR expression and TR gene rearrangement, 10 of 12 cases of ENKTL were decided as a T-lineage tumor. In conclusion, because of common TR silence and poor DNA quality, consideration of both immunohistochemistry and TR gene rearrangement is necessary to determine the lineage of ENKTL.
结外 NK/T 细胞淋巴瘤，鼻型（ENKTL）的细胞谱系由 T 细胞受体（TR）或 TR 基因重排决定。在 ENKTL 中，通过 TR 免疫组化，往往难以确定 TR 阳性细胞是否为肿瘤细胞，尤其是当 TR 在肿瘤细胞的一部分中表达时。为了分析 T 细胞系 ENKTL 中的 TR 表达模式和 TR 重排，我们对 12 例在免疫组化中显示 TRβF1 表达的 ENKTL 进行了 EBV 编码小 RNA（EBER）/T 细胞受体（TCR）βF1 和 CD56/TCRβF1 的双重免疫荧光染色。使用商业 BIOMED-2 多重聚合酶链反应系统分析 TR 基因重排。免疫组化显示，所有 12 例均在浸润细胞中广泛表达 TCRβF1，范围为 100%至<1%。其中 2 例同时表达 TCRβF1 和 TCR cγM1。通过双重染色，10 例证实 EBER/TCR-βF1 阳性。1 例未显示 EBER/TCR-βF1 阳性细胞，但显示 CD56/TCRβF1 阳性结果。在 12 例中，5 例 DNA 质量差，其中 3 例无聚合酶链反应产物，2 例显示低高度的非特异性峰。5 例 DNA 质量良好的病例中有 2 例显示 TR 基因单克隆重排。基于 TR 表达和 TR 基因重排，12 例 ENKTL 中有 10 例被确定为 T 细胞系肿瘤。总之，由于 TR 沉默和 DNA 质量差很常见，因此需要考虑免疫组化和 TR 基因重排来确定 ENKTL 的谱系。
