我们旨在研究TCL1家族阴性T细胞幼淋巴细胞白血病（T-PLL）的形态学和免疫表型特征。对20例TCL1家族阴性T-PLL进行了研究。白血病细胞的倍增时间从小于2天不等最长可达5年以上，中位数为5.5个月。白血病细胞为小至中等大小，具有圆形至不规则的细胞核、不同程度浓缩的染色质和少量无颗粒细胞质。 11 例 (55%) 病例中发现可见的核仁。在所有病例中均发现了细胞质泡/突起，但其发生情况因病例而异。骨髓活检显示 90% 的病例呈间质型，其余 10% 的病例呈弥漫型。流式细胞免疫表型分析显示所有病例白血病细胞均为CD4阳性； 3 (15%) 也显示出同时的 CD8 表达。所有病例CD2和CD5均为阳性。 20 例中有 19 例 (95%) 表面 CD3 和 CD7 呈阳性，所有 CD3 阳性病例均表达 T 细胞受体 αβ。与原型T-PLL病例相比，这两组患者有许多共同的免疫表型发现，除了CD8和CD26，这两者在原型T-PLL病例中更常见。TCL1家族阴性T-PLL病例具有以下形态学和免疫表型特征：类似于原型 T-PLL。它们的特征是具有 CD4 阳性 T 细胞受体 αβ 表型的中小型成熟 T 细胞的肿瘤性增殖。肿瘤细胞经常维持泛T抗原表达。认识这些形态学和免疫表型特征将有助于准确诊断 T-PLL 的这种罕见亚型。© 作者 2024。由牛津大学出版社代表美国临床病理学会出版。版权所有。如需商业重复使用，请联系 reprints@oup.com 获取转载和转载的翻译权。所有其他权限均可通过我们网站文章页面上的“权限”链接通过我们的 RightsLink 服务获得 - 欲了解更多信息，请联系journals.permissions@oup.com。

We sought to investigate the morphologic and immunophenotypic characteristics of TCL1 family-negative T-cell prolymphocytic leukemia (T-PLL).Twenty cases of TCL1 family-negative T-PLL were studied.The doubling time of leukemic cells ranged from less than 2 days to more than 5 years, with a median of 5.5 months. Leukemic cells were small to medium-sized, with round to irregular nuclei, variably condensed chromatin, and small amounts of agranular cytoplasm. A visible nucleolus was identified in 11 (55%) cases. Cytoplasmic blebs/protrusions were identified in all cases, but their occurrence was highly variable from case to case. Bone marrow biopsy showed an interstitial pattern in 90% of cases and a diffuse pattern in the remaining 10% of cases. Flow cytometric immunophenotypic analysis showed that the leukemic cells in all cases were CD4 positive; 3 (15%) also showed concurrent CD8 expression. All cases were positive for CD2 and CD5. Surface CD3 and CD7 were positive in 19 of 20 (95%) cases, and all CD3-positive cases expressed the T-cell receptor αβ. Compared with prototypic T-PLL cases, these 2 groups shared many immunophenotypic findings, except CD8 and CD26, both of which were more commonly expressed in prototypic T-PLL cases.TCL1 family-negative T-PLL cases have morphologic and immunophenotypic features that are similar to prototypic T-PLL. They are characterized by neoplastic proliferation of small to medium-sized mature T cells with CD4-positive T-cell receptor αβ phenotype. Tumor cells frequently maintain pan-T antigen expression. Recognizing these morphologic and immunophenotypic features will aid in accurately diagnosing this rare subset of T-PLL.© The Author(s) 2024. Published by Oxford University Press on behalf of American Society for Clinical Pathology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.