Department of Haematology and Oncology, Graduate School of Medicine, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
Department of Diagnostic Pathology, Kyoto University Hospital, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
Int J Hematol. 2020 May;111(5):724-732. doi: 10.1007/s12185-019-02810-y. Epub 2020 Jan 1.
Mucosa-associated lymphoid tissue (MALT) lymphoma with t(11;18)(q21;q21), resulting in an API2-MALT1 fusion transcript, is reported to rarely transform into aggressive lymphoma. Here, we report the clinical course of a patient who experienced histologic transformation after 20 years' disease history of t(11;18)-positive MALT lymphoma. The patient suddenly developed a large intrapelvic mass and ascites with a rapid increase in lactate dehydrogenase. Cytology of the ascites detected large abnormal cells, and flow cytometric analysis revealed that the cells were positive for cytoplasmic CD3, CD4, and CD38, and partially positive for CD7, but negative for CD19 and CD20. Antigen receptor gene rearrangement analysis and in situ hybridization of the immunoglobulin light chains confirmed that the tumor cells were of B-cell lineage. Chromosomal analysis showed complex karyotypes with intraclonal variation, and in addition to t(11;18), t(8;14) and heterozygous loss of the TP53 were demonstrated. Although histological and phenotypic features were significantly altered from the original MALT lymphoma, the presence of t(11;18) led us to the diagnosis of histologic transformation of MALT lymphoma. Although transformation of t(11;18)-positive MALT lymphoma into aggressive lymphoma is extremely rare, it may occur, probably with additional genetic abnormalities such as cMYC rearrangement and/or the loss of TP53.
黏膜相关淋巴组织（MALT）淋巴瘤伴 t（11；18）（q21；q21），导致 API2-MALT1 融合转录本，据报道很少转化为侵袭性淋巴瘤。在此，我们报告了一例 t（11；18）阳性 MALT 淋巴瘤病史 20 年后发生组织学转化的患者的临床过程。患者突然出现大型盆腔肿块和腹水，乳酸脱氢酶迅速升高。腹水的细胞学检测到大量异常细胞，流式细胞术分析显示细胞细胞质 CD3、CD4 和 CD38 阳性，部分 CD7 阳性，但 CD19 和 CD20 阴性。抗原受体基因重排分析和免疫球蛋白轻链原位杂交证实肿瘤细胞为 B 细胞谱系。染色体分析显示具有克隆内变异的复杂核型，除 t（11；18）外，还显示 t（8；14）和 TP53 杂合性缺失。尽管组织学和表型特征与原始 MALT 淋巴瘤有明显改变，但存在 t（11；18）导致我们诊断为 MALT 淋巴瘤的组织学转化。尽管 t（11；18）阳性 MALT 淋巴瘤转化为侵袭性淋巴瘤极为罕见，但可能会发生，可能伴有额外的遗传异常，如 cMYC 重排和/或 TP53 缺失。
