Khalidi H S, Brynes R K, Browne P, Koo C H, Battifora H, Medeiros L J
Division of Pathology, City of Hope National Medical Center, Duarte, California, USA.
Mod Pathol. 1998 Oct;11(10):983-8.
The CD5 antigen is a T-cell associated marker that is also usually expressed by two B-cell neoplasms, chronic lymphocytic leukemia/small lymphocytic lymphoma and mantle cell lymphoma. We observed CD5 antigen expression in a subset of cases of intravascular large B-cell lymphoma (IVLBL), and we report here five cases. The patients, two men and three women, ranged in age from 59 to 81 years. Biopsy specimens were obtained from kidney, lung, bone marrow, abdominal wall, and neck, the latter involving a lymphangioma. All of the cases had histologic features typical of IVLBL, with large and atypical lymphoid cells located predominantly within blood vessels. Immunohistochemical studies performed using routinely fixed, paraffin-embedded tissue sections showed that the neoplastic cells were B cells, positive for the CD20 antigen and negative for the CD3 or CD43 antigens. All cases were also positive for the CD5 antigen. One case had an immunoglobulin heavy chain gene rearrangement shown by using a polymerase chain reaction method. The finding of CD5 antigen expression in a subset of IVLBL cases adds to other evidence in the literature suggesting that IVLBL is a heterogeneous entity. We considered the possibility that these cases were related to or represented unusual histologic forms of transformation from either chronic lymphocytic leukemia/small lymphocytic lymphoma or mantle cell lymphoma. All of the cases, however, were negative for the CD23 antigen and cyclin D1 (bcl-1) protein, which is evidence against this interpretation. The biologic significance of CD5 antigen expression in cases of IVLBL is uncertain. These neoplasms might arise from a separate lineage of CD5-positive B cells or from a specific, early stage of B-cell differentiation. Alternatively, some investigators have suggested that CD5 antigen expression by B cells is a marker of activation.
CD5抗原是一种与T细胞相关的标志物，通常也由两种B细胞肿瘤即慢性淋巴细胞白血病/小淋巴细胞淋巴瘤和套细胞淋巴瘤表达。我们在血管内大B细胞淋巴瘤（IVLBL）的一部分病例中观察到了CD5抗原表达，在此报告5例。患者为2名男性和3名女性，年龄在59岁至81岁之间。活检标本取自肾脏、肺、骨髓、腹壁和颈部，后者累及一个淋巴管瘤。所有病例均具有IVLBL的典型组织学特征，大的非典型淋巴样细胞主要位于血管内。使用常规固定、石蜡包埋的组织切片进行的免疫组化研究显示，肿瘤细胞为B细胞，CD20抗原阳性，CD3或CD43抗原阴性。所有病例的CD5抗原也均为阳性。1例通过聚合酶链反应方法显示有免疫球蛋白重链基因重排。IVLBL一部分病例中CD5抗原表达的发现为文献中的其他证据增添了内容，提示IVLBL是一种异质性实体。我们考虑了这些病例与慢性淋巴细胞白血病/小淋巴细胞淋巴瘤或套细胞淋巴瘤相关或代表其不寻常组织学转化形式的可能性。然而，所有病例的CD23抗原和细胞周期蛋白D1（bcl-1）蛋白均为阴性，这一证据不支持这种解释。IVLBL病例中CD5抗原表达的生物学意义尚不确定。这些肿瘤可能起源于CD5阳性B细胞的一个独立谱系或B细胞分化的一个特定早期阶段。另外，一些研究者提出B细胞表达CD5抗原是激活的一个标志物。
