Greer Wenda L, Lee Christine L Y, Callanan Mary B, Zayed Ekram, Sadek Irene
Department of Pathology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.
Am J Hematol. 2003 Oct;74(2):112-8. doi: 10.1002/ajh.10393.
The majority of follicular lymphoma and Burkitt's lymphoma are associated with reciprocal translocations involving BCL2 and cMYC, respectively. Unusual reports of aggressive lymphoma presenting with both translocations have been described as well as rare cases with a third structural alteration usually involving BCL6. The patient described here presented with aggressive high-grade lymphocytic leukemia, FAB subtype L2 (ALL-L2), and three reciprocal translocations, t(14;18)(q32;q21), t(8;14)(q24.1;q32), and t(1;2) (q22-23;p13). Despite immature morphology the leukemic blasts had a mature B-cell phenotype; they were positive for surface immunoglobulin heavy chains and negative for CD34, TdT, and CD10. Most reported dual t(14;18)/t(8;14) cases have not shown sIg and were positive for CD10. Molecular genetic analyses showed the typical rearrangements of BCL2 and cMYC as well as the FCGR2B gene on chromosome 1q23. The occurrence of a third oncogene rearrangement in association with the dual BCL2, cMYC translocations in ALL patients is very rare. To our knowledge, this is the first case where the third hit involves the FCGR2B locus. This report reiterates the poor prognosis associated with activation of cMYC together with elevated Bcl-2 expression. These data also support recent evidence that dysregulation of FCGR2B may play a role in tumor progression.
大多数滤泡性淋巴瘤和伯基特淋巴瘤分别与涉及BCL2和cMYC的相互易位相关。已有侵袭性淋巴瘤同时出现这两种易位的罕见报道，以及罕见的伴有通常涉及BCL6的第三种结构改变的病例。本文所述患者表现为侵袭性高级别淋巴细胞白血病，FAB亚型L2（ALL-L2），并伴有三种相互易位，即t(14;18)(q32;q21)、t(8;14)(q24.1;q32)和t(1;2)(q22 - 23;p13)。尽管白血病原始细胞形态不成熟，但具有成熟B细胞表型；它们表面免疫球蛋白重链呈阳性，而CD34、TdT和CD10呈阴性。大多数报道的双重t(14;18)/t(8;14)病例未显示sIg且CD10呈阳性。分子遗传学分析显示了BCL2和cMYC以及1号染色体q23上FCGR2B基因的典型重排。在ALL患者中，与双重BCL2、cMYC易位相关的第三种癌基因重排的发生非常罕见。据我们所知，这是首例第三次打击涉及FCGR2B基因座的病例。本报告重申了与cMYC激活以及Bcl-2表达升高相关的不良预后。这些数据也支持了近期的证据，即FCGR2B失调可能在肿瘤进展中起作用。
