Yuan Constance M, Vergilio Jo-Anne, Zhao Xian-Feng, Smith Treasa K, Harris Nancy Lee, Bagg Adam
Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL 32610, USA.
Hum Pathol. 2005 Jul;36(7):784-91. doi: 10.1016/j.humpath.2005.05.008.
Angioimmunoblastic T-cell lymphoma (AITCL) is a histologically distinct and relatively common subtype of T-cell lymphoma. Although the putative normal cell counterpart is a mature CD4+ T cell, the precise cell of origin remains elusive. We evaluated cases with a diagnosis of AITCL to determine the specificity and utility of CD10 coexpression, particularly by flow cytometry (FCM), in facilitating this diagnosis. Coexpression of BCL6 was also assessed. Eight AITCL cases were evaluated histologically, immunohistochemically, and by 4-color FCM. Four cases of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), were also analyzed. The lymphoma cells in all 8 AITCL cases were CD4+, CD45RO+ T cells, with classic extrafollicular meshworks of CD21/CD23/CD35+ follicular dendritic cells. Furthermore, all cases of AITCL cases contained interfollicular CD10+ cells by immunohistochemistry, and increased coexpression of CD10 on T cells was also detected in 6 of 8 cases by FCM. CD10 coexpression was not observed in all 4 PTCL-NOS cases. Although not specific for AITCL, increased numbers of BCL6+ cells were seen in AITCL as compared with PTCL-NOS. Double immunohistochemistry performed on an AITCL case with high numbers of BCL6+ cells highlighted coexpression of BCL6 and CD4 on the same cells. The finding suggests that AITCL may be a neoplasm of (possibly intrafollicular) CD10+, BCL6+, and CD4+ memory T cells. Although our series is small, our results suggest that CD10 coexpression may be a useful discriminant, particularly if the differential diagnosis is PTCL-NOS, and demonstrate that this can be determined by FCM.
血管免疫母细胞性T细胞淋巴瘤（AITCL）是一种组织学上独特且相对常见的T细胞淋巴瘤亚型。尽管推测其正常细胞对应物是成熟的CD4 + T细胞，但其确切起源细胞仍不清楚。我们评估了诊断为AITCL的病例，以确定CD10共表达，特别是通过流式细胞术（FCM）在辅助该诊断中的特异性和实用性。还评估了BCL6的共表达情况。对8例AITCL病例进行了组织学、免疫组织化学和四色FCM评估。还分析了4例未另行指定的外周T细胞淋巴瘤（PTCL-NOS）。所有8例AITCL病例中的淋巴瘤细胞均为CD4 +、CD45RO + T细胞，伴有CD21 / CD23 / CD35 +滤泡树突状细胞的典型滤泡外网状结构。此外，通过免疫组织化学，所有AITCL病例的滤泡间均含有CD10 +细胞，并且通过FCM在其中6例8例病例中也检测到T细胞上CD10共表达增加。在所有4例PTCL-NOS病例中均未观察到CD10共表达。尽管对AITCL不具有特异性，但与PTCL-NOS相比，AITCL中BCL6 +细胞数量增加。对一例BCL6 +细胞数量较多的AITCL病例进行的双重免疫组织化学显示，同一细胞上BCL6和CD4共表达。这一发现表明AITCL可能是（可能是滤泡内的）CD10 +、BCL6 +和CD4 +记忆T细胞的肿瘤。尽管我们的病例系列较小，但我们的结果表明CD10共表达可能是一种有用的鉴别指标，特别是在鉴别诊断为PTCL-NOS时，并证明这可以通过FCM确定。
