BACKGROUND Epstein-Barr virus is associated with many human hematopoietic neoplasms; however, Epstein-Barr virus-positive mucosa-associated lymphoid tissue lymphoma is extremely rare. In routine clinical practice, detection of mucosa-associated lymphoid tissue lymphoma and diffuse large B-cell lymphoma in a tissue sample presumes a clonal relation between these neoplasms and that diffuse large B-cell lymphoma developed by transformation of the mucosa-associated lymphoid tissue lymphoma. However, evidence to support this presumption is sparse and controversial. Assessment of the clonal relationship of the lymphoid components of a composite lymphoma is important for understanding its pathogenesis and correct diagnosis. CASE PRESENTATION We present an unusual case of composite lymphoma (Epstein-Barr virus-positive mucosa-associated lymphoid tissue lymphoma/Epstein-Barr virus-negative diffuse large B-cell lymphoma) in the parotid salivary gland of a 62-year-old Caucasian woman with Sjögren's syndrome and rheumatoid arthritis. Simultaneous occurrence of mucosa-associated lymphoid tissue lymphoma and diffuse large B-cell lymphoma in the parotid salivary gland led us to initially assume a clonal relationship between diffuse large B-cell lymphoma and mucosa-associated lymphoid tissue lymphoma. Epstein-Barr virus was detected by in situ hybridization and polymerase chain reaction in the mucosa-associated lymphoid tissue lymphoma, but not in diffuse large B-cell lymphoma, suggesting that these lymphomas were not clonally related. Fragment analysis of frame region 3 polymerase chain reaction products from microdissected mucosa-associated lymphoid tissue lymphoma and diffuse large B-cell lymphoma components revealed different clonal pattern rearrangements of the immunoglobulin heavy chain gene. CONCLUSIONS Our patient's case highlights the importance of assessing the clonal relationships of the lymphoid components of a composite lymphoma and Epstein-Barr virus screening in mucosa-associated lymphoid tissue lymphoma in patients with autoimmune disease.

中文翻译：

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干燥综合征和类风湿性关节炎患者腮腺中的复合爱泼斯坦-巴尔病毒阳性的粘膜相关淋巴组织淋巴瘤和爱泼斯坦-巴尔病毒阴性的弥漫性大B细胞淋巴瘤：病例报告。

背景爱泼斯坦-巴尔病毒与许多人类造血肿瘤有关。然而，EB病毒阳性的粘膜相关淋巴样组织淋巴瘤极为罕见。在常规临床实践中，在组织样品中检测粘膜相关淋巴样组织淋巴瘤和弥漫性大B细胞淋巴瘤的前提是，这些肿瘤与通过黏膜相关淋巴样组织淋巴瘤转化而形成的弥漫性大B细胞淋巴瘤之间存在克隆关系。 。但是，支持这种推论的证据很少而且有争议。评估复合淋巴瘤的淋巴成分的克隆关系对于理解其发病机理和正确诊断很重要。病例介绍我们在62岁的白种人腮腺唾液腺中发现了一个罕见的复合淋巴瘤病例（Epstein-Barr病毒阳性粘膜相关淋巴样组织淋巴瘤/ Epstein-Barr病毒阴性弥漫性大B细胞淋巴瘤）干燥综合征和类风湿关节炎的女性。腮腺唾液腺同时发生粘膜相关淋巴样组织淋巴瘤和弥漫性大B细胞淋巴瘤，使我们最初假设弥漫性大B细胞淋巴瘤与粘膜相关淋巴样组织淋巴瘤之间存在克隆关系。通过原位杂交和聚合酶链反应在粘膜相关淋巴样组织淋巴瘤中检测到爱泼斯坦-巴尔病毒，但在弥漫性大B细胞淋巴瘤中未检出，表明这些淋巴瘤与克隆无关。显微解剖的黏膜相关淋巴组织淋巴瘤和弥漫性大B细胞淋巴瘤成分的框架区3聚合酶链反应产物的片段分析揭示了免疫球蛋白重链基因的不同克隆模式重排。结论我们的患者病例突出了评估自身免疫性疾病患者黏膜相关淋巴组织淋巴瘤中复合淋巴瘤淋巴成分的克隆关系和爱泼斯坦-巴尔病毒筛查的重要性。