Yegappan S, Schnitzer B, Hsi E D
Department of Clinical Pathology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
Mod Pathol. 2001 Mar;14(3):191-6. doi: 10.1038/modpathol.3880284.
On occasion, follicle center lymphomas (FCL) may contain a marginal-zone (MZ) component in which the interfollicular lymphoid cells take on an MZ cell morphology. In the past, these have been termed composite lymphomas. However, recent studies suggest that the two components are clonally related. It is unknown whether the bcl-2 translocation present in most FCLs is present in the cells that demonstrate MZ cell morphology. We have identified three cases of low-grade FCL with a MZ component suitable for laser capture microdissection (LCM) of the two components. Cases were immunophenotyped in paraffin section with antibodies to CD10, CD20, bcl-2, and bcl-6. LCM was done to isolate cells from each component. Polymerase chain reaction for t(14;18) using primers to the major breakpoint region was performed on DNA extracts. The sensitivity of the PCR assay was decreased to 5%--10% follicle center cells in a background of reactive tonsil cells. All three cases showed different phenotypes in each component. The FCL component was positive for all four of the above markers, whereas the MZ component expressed only CD20 and bcl-2. Both components showed t(14;18) amplicons of identical size, with the MZ component signal being stronger than the 5%--10% sensitivity control, suggesting that the signal was not from rare, contaminating FCL cells. These results confirm that both components are clonally related and support the theory that these are indeed FCLs with MZ differentiation (that retain the t(14;18)) rather than the reverse, MZ lymphoma with follicle center differentiation.
偶尔，滤泡中心淋巴瘤（FCL）可能包含边缘区（MZ）成分，其中滤泡间淋巴样细胞呈现MZ细胞形态。过去，这些被称为复合淋巴瘤。然而，最近的研究表明这两种成分是克隆相关的。大多数FCL中存在的bcl-2易位是否存在于呈现MZ细胞形态的细胞中尚不清楚。我们已鉴定出3例低级别FCL，其具有适合对两种成分进行激光捕获显微切割（LCM）的MZ成分。对病例进行石蜡切片免疫表型分析，使用抗CD10、CD20、bcl-2和bcl-6抗体。进行LCM以从每个成分中分离细胞。对DNA提取物进行使用主要断裂点区域引物的t(14;18)聚合酶链反应。在反应性扁桃体细胞背景下，PCR检测的灵敏度降至5% - 10%的滤泡中心细胞。所有3例病例的每个成分都显示出不同的表型。FCL成分对上述所有四种标志物均呈阳性，而MZ成分仅表达CD20和bcl-2。两种成分均显示大小相同的t(14;18)扩增子，MZ成分的信号强于5% - 10%的灵敏度对照，表明该信号并非来自罕见的、污染的FCL细胞。这些结果证实两种成分是克隆相关的，并支持以下理论，即这些确实是具有MZ分化的FCL（保留t(14;18)），而非相反的具有滤泡中心分化的MZ淋巴瘤。
