Department of Pathology, Stanford University School of Medicine, Stanford, CA.
Appl Immunohistochem Mol Morphol. 2020 May/Jun;28(5):384-388. doi: 10.1097/PAI.0000000000000738.
Myeloid cell nuclear differentiation antigen (MNDA) is an immunohistochemical marker that is used to distinguish marginal zone lymphomas (MZLs) from other small B-cell lymphomas. An index case that showed MNDA staining in primary follicles prompted the current study to evaluate whether MNDA expression is widespread in primary follicles and to address whether it poses a potential diagnostic pitfall. Of the 15 cases with primary follicles identified by a search of the laboratory information system, 7 had positive MNDA staining. In all cases, there was weak nuclear staining similar to what is typical of MNDA staining in MZLs. All cases showed intense nuclear signal in myeloid lineage cells such as neutrophils, which served as positive internal controls. The histologic and cytologic features of primary follicles and MZLs showed overlapping features, particularly in small biopsies. Our results indicate that weak nuclear MNDA staining can act as a potential pitfall in the evaluation of small B-cell lymphomas. Correlation with other immunohistochemical markers that are useful in the workup of small B-cell lymphomas, as well as those that outline immunoarchitectural features of lymphoid follicles, is suggested when both entities are part of the differential diagnosis. Our results underscore the need for caution in the interpretation of weak nuclear MNDA staining in the evaluation of small B-cell lymphomas.
髓系细胞核分化抗原（MNDA）是一种免疫组织化学标志物，用于区分边缘区淋巴瘤（MZL）和其他小 B 细胞淋巴瘤。一个在原发滤泡中显示 MNDA 染色的索引病例促使本研究评估 MNDA 表达是否广泛存在于原发滤泡中，并探讨其是否构成潜在的诊断陷阱。通过实验室信息系统的搜索，在 15 例具有原发滤泡的病例中，有 7 例 MNDA 染色阳性。在所有病例中，均可见类似 MZL 中 MNDA 染色的弱核染色。所有病例均在髓系细胞如中性粒细胞中显示强烈的核信号，这些细胞作为阳性内部对照。原发滤泡和 MZL 的组织学和细胞学特征具有重叠特征，尤其是在小活检中。我们的结果表明，弱核 MNDA 染色在评估小 B 细胞淋巴瘤时可能成为潜在的陷阱。当这两种病变都是鉴别诊断的一部分时，建议与其他在小 B 细胞淋巴瘤检查中有用的免疫组织化学标志物以及那些概述淋巴滤泡免疫结构特征的标志物进行相关性分析。我们的结果强调了在评估小 B 细胞淋巴瘤时，对弱核 MNDA 染色的解释需要谨慎。
