原发于骨髓伴CD20表达的CD8阳性细胞毒性T细胞淋巴瘤一例附文献复习

Primary bone marrow CD8 cytotoxic T-cell lymphoma coexpressed CD20： a case report and literatures review

目的报道1例罕见的原发于骨髓伴CD20表达的CD8阳性细胞毒性T细胞淋巴瘤患者的诊断、鉴别诊断和治疗经过。方法分析患者的发病经过、临床特点、治疗反应和转归，对患者的骨髓和皮肤标本进行包括形态学、流式细胞术、免疫组织化学和分子生物学在内的系列检测以助诊断和鉴别诊断。结果患者骨髓中有大量异常T淋巴细胞浸润，骨髓和皮肤标本经流式细胞术和免疫组化检查发现CD20弱表达、CD8、CD2、CD3、CD5及TIA阳性，PAX．5、CD4、CD56、CD57、CD30、ALK-1、P53及TdT等均阴性，Ki-67阳性-5％，诊断为伴CD20表达的CD8阳性细胞毒性T细胞淋巴瘤，原发于骨髓，临床呈惰性经过，3年后侵犯皮肤和其他脏器并迅速进展，虽给予强化疗但患者最终死亡。结论原发于骨髓伴CD20表达的CD8阳性细胞毒性T细胞淋巴瘤非常特殊和罕见，相关的发病机制和治疗策略有待于进一步深入探索。

Objective To report the diagnosis, differential diagnosis and treatment of a rare case of primary bone marrow CD8 ＋ cytotoxic T-cell lymphoma coexpressed CD20. Methods The clinical character- istics, therapeutic course and the outcome of this patient were reviewed. Meanwhile, a series of examinations including morphology, flow cytometry, immunohistoehemistry and molecular biology of bone marrow and skin samples were also performed. Results Bone marrow biopsy showed an extensive involvement by abnormal T lymphocytes. Flow cytometry and immunohistochemistry showed weakly positive CD20, CD8 （ ＋ ）, CD2 （＋）, CD3（ ＋ ）, CD5（＋）, TIA（ ＋ ）, PAX-5（ - ）, CD4（ - ）, CD56（ - ）, CD57（ - ）, CD30（ - ）, ALK-1 （ - ） , P53（ - ） , TdT（ - ） , Ki-67~5%. A final diagnosis of primary bone marrow CD8＋ eytotoxie T-cell lymphoma coexpressed CD20 was made. The patient initially presented a relatively indolent course was, but he was expired in the end 3 years later due to extensive involvements of skin and other organs though timely therapy was administrated. Conelusions Primary bone marrow CD8 cytotoxic T-cell lymphoma coexpressed CD20 was encountered rarely in clinical practice, which might be a challenging in terms of diagnosis and differential diagnosis. Further investigation of pathogenesis and therapeutic strategies of this rare disease was warranted.