Almasri N M, Zaer F S, Iturraspe J A, Braylan R C
Department of Pathology, Immunology, and Laboratory Medicine, University of Florida College of Medicine, Gainesville 32610-0275, USA.
Mod Pathol. 1997 Jul;10(7):650-6.
Gastric lymphomas seem to have unique clinical, pathologic, and immunophenotypic features that set them apart from nodal lymphomas. Microscopic examination of endoscopic biopsy specimens is the most frequent procedure used to diagnose gastric tumors, but it is very difficult, and sometimes impossible, to recognize lymphomas in endoscopic samples by histologic or even immunohistologic methods. Because most gastric lymphomas are of B-cell origin, we used flow cytometry to assess B-cell clonality in gastric biopsy specimens containing dense lymphocytic infiltrates thought to represent lymphoma. We prepared viable cell suspensions from unfixed specimens obtained from 29 consecutive patients who had a previous microscopic diagnosis of suspicious gastric lymphoid infiltrates. We performed immunophenotypic studies with multicolor flow cytometry, and we assessed clonality by examination of immunoglobulin (Ig) light-chain expression analyzed exclusively on B cells identified by anti-CD20 or CD19 antibodies. The mean number of cells recovered was 1.04 x 10(6), from an average of 5.5 gastric biopsy fragments per patient. In 26 of the 29 patients, the number of cells was adequate for analysis. We detected B-cell monoclonality in 16 cases, including 5 in which the percentage of clonal B cells was less than 5%. Of the 16 cases, only 8 could be diagnosed as lymphomas on morphologic grounds alone; the remaining 8 patients had either suspicious lymphoid infiltrates or chronic gastritis. The three cases with an insufficient number of cells were considered non-neoplastic either on histologic grounds alone or in conjunction with Southern analysis of Ig genes. We conclude that flow cytometric immunophenotypic analysis of freshly prepared cell suspensions obtained from endoscopic biopsy specimens can be used to evaluate gastric lymphocytic infiltrates. Specifically, the analysis of surface Ig light-chain expression on B cells distinguishes between monoclonal (lymphoma) and polyclonal (nonlymphoma) infiltrates. The rapidity, ease, quantitative properties, and sensitivity of this technique make it a supplement to the morphologic assessment of gastric lymphoid infiltrates.
胃淋巴瘤似乎具有独特的临床、病理和免疫表型特征，使其有别于淋巴结淋巴瘤。内镜活检标本的显微镜检查是诊断胃肿瘤最常用的方法，但通过组织学甚至免疫组织学方法在内镜样本中识别淋巴瘤非常困难，有时甚至不可能。由于大多数胃淋巴瘤起源于B细胞，我们使用流式细胞术评估胃活检标本中B细胞的克隆性，这些标本含有被认为代表淋巴瘤的密集淋巴细胞浸润。我们从29例先前经显微镜诊断为可疑胃淋巴浸润的连续患者获取的未固定标本中制备了活细胞悬液。我们用多色流式细胞术进行免疫表型研究，并通过检测仅在抗CD20或CD19抗体识别的B细胞上分析的免疫球蛋白（Ig）轻链表达来评估克隆性。回收的细胞平均数为1.04×10⁶，每位患者平均有5.5个胃活检碎片。29例患者中有26例的细胞数量足以进行分析。我们在16例中检测到B细胞单克隆性，其中5例克隆性B细胞百分比小于5%。在这16例中，仅8例仅凭形态学依据可诊断为淋巴瘤；其余8例患者有可疑淋巴浸润或慢性胃炎。细胞数量不足的3例仅根据组织学依据或结合Ig基因的Southern分析被认为是非肿瘤性的。我们得出结论，对内镜活检标本获取的新鲜制备细胞悬液进行流式细胞术免疫表型分析可用于评估胃淋巴细胞浸润。具体而言，对B细胞表面Ig轻链表达的分析可区分单克隆（淋巴瘤）和多克隆（非淋巴瘤）浸润。该技术的快速性、简便性、定量特性和敏感性使其成为胃淋巴浸润形态学评估的补充方法。
