复合淋巴瘤（CL），即B细胞淋巴瘤和T细胞淋巴瘤的混合症状，非常罕见。本文使用免疫组织化学、流式细胞术和下一代测序（NGS）报告了三例该病例，以确定CL的病理和分子特征。在第一例中，患者因全身弥漫性瘙痒性斑疹而入院。皮损切除活检显示为T细胞淋巴瘤。同时，分期骨髓（BM）活检显示为弥漫大B细胞淋巴瘤（DLBCL）。经过R-CHOP（利妥昔单抗、环磷酰胺、多柔比星、长春新碱和泼尼松）治疗后，患者病情显著好转，皮疹消失，瘙痒缓解。另外两位患者因淋巴结肿大入院，经过淋巴结核心针活检、BM活检、BM骨髓抽吸和流式细胞术诊断为DLBCL和滤泡性淋巴瘤（FL）。在R-CHOP和R-COP（利妥昔单抗、环磷酰胺、长春新碱和泼尼松）治疗后，两例患者达到部分缓解（CRu）和完全缓解（CR）。然而，一到两年后，他们的淋巴结肿大复发。令人震惊的事实是，淋巴结肿大再次活检显示为周围T细胞淋巴瘤（PTCL）和血管免疫母细胞性T细胞淋巴瘤（AITL）。NGS结果显示DNA甲基转移酶3a（DNMT3a）、异柠檬酸脱氢酶2（IDH2）、Ras同源基因家族成员A（RHOA）、剪切因子3B亚基1（SF3B1）和肿瘤蛋白p53（TP53）的突变。在免疫化疗后，这些患者再次达到CRu和CR。然而，他们又经历了T细胞淋巴瘤的第二次复发。最终，他们因病情进展而死亡。我们发现CL的发病与EB病毒感染以及DNMT3a、IDH2和TP53突变密切相关，而疾病的预后与T细胞淋巴瘤成分有关。

Composite lymphoma (CL) involving B-cell lymphoma and T-cell lymphoma is extremely rare. Herein, we report three such cases using immunohistochemistry, flow cytometry, and the next-generation sequencing (NGS) to identify the pathological and molecular characteristics of CL. In the first case, the patient was admitted to hospital for generalized pruritic maculopapular rash over the whole body. An excisional biopsy of the skin lesions showed T-cell lymphoma. At the same time, the staging bone marrow (BM) biopsy revealed a diffuse large B-cell lymphoma (DLBCL). After R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) therapies, the patient produced a good response with substantial dissipation of the rashes and relief of skin. The other two patients were admitted to hospital due to lymphadenopathy and were diagnosed with DLBCL and follicular lymphoma (FL) after core needle biopsy of lymph nodes, BM biopsy, BM aspiration, and flow cytometry. Following R-CHOP and R-COP (rituximab, cyclophosphamide, vincristine, and prednisone) therapies, they achieved complete remission unconfirmed (CRu) and complete remission (CR). However, one or two years later, they suffered a relapse of lymphadenopathy. The shocking fact was that re-biopsy of lymphadenopathy revealed peripheral T-cell lymphoma (PTCL) and angioimmunoblastic T-cell lymphoma (AITL). NGS findings identified DNA methyltransferase 3a (DNMT3a), isocitrate dehydrogenase 2 (IDH2), Ras homolog gene family, member A (RHOA), splicing factor 3B subunit 1 (SF3B1), and tumor protein p53 (TP53) mutations. After immunochemotherapy, these patients achieved CRu and CR again. Nevertheless, they suffered a second relapse of T-cell lymphoma. Finally, they died due to progression of disease. We found that the occurrence of CL is associated with Epstein-Barr virus infection and DNMT3a, IDH2, and TP53 mutations, and the prognosis of the disease is closely related to the T-cell lymphoma components.