Dasatinib, a second-generation tyrosine kinase inhibitor (TKI), used as treatment for chronic myeloid leukemia, BCR::ABL1-positive (CML), is complicated by pleural or pericardial effusions in about one-third of patients. Besides, in exceptional instances, effusion-based neoplastic B-cell lymphoproliferations have been described. Here, we report an HHV8-negative, EBV-positive large B-cell lymphoma presenting as a pericardial effusion in a patient with CML treated with dasatinib for 23 months, without associated tumor mass or lymphadenopathies. Large tumor cells showed a B-cell phenotype (CD20+, CD79+), with evidence of EBV infection (EBER-ISH+), but HHV8 (LANA-1) negative. Monoclonal IG gene rearrangements were identified. BCL2, BCL6, and MYC genes were not rearranged. Despite the aggressive cytomorphology the patient was in complete remission after 4 cycles of R-CHOP after 8 months follow-up. Four other cases of large B-cell effusion-based lymphomas developed in the setting of dasatinib therapy for CML have been reported in the literature. The four cases were HHV8-negative and one case was EBV-positive. Three of the four patients experienced a benign clinical course, which is in contrast to HHV8-positive primary effusion lymphoma (PEL). The mechanisms of development of these effusion-based B-cell lymphoproliferations in patients receiving TKI are not completely elucidated. Acute or relapsing effusions during TKI treatment in the setting of CML should be cytologically examined to exclude clonal B-cell lymphoproliferations.

中文翻译：

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HHV8 阴性原发性积液性大 B 细胞淋巴瘤患者慢性粒细胞白血病，达沙替尼治疗下 BCR::ABL1 阳性：一例新病例报告并文献复习

达沙替尼是一种第二代酪氨酸激酶抑制剂 (TKI)，用于治疗慢性粒细胞白血病，BCR::ABL1阳性 (CML)，大约三分之一的患者会并发胸腔或心包积液。此外，在特殊情况下，已经描述了基于积液的肿瘤性 B 细胞淋巴增殖。在这里，我们报告了在接受达沙替尼治疗 23 个月的 CML 患者中表现为心包积液的 HHV8 阴性、EBV 阳性大 B 细胞淋巴瘤，没有相关的肿瘤块或淋巴结病。大肿瘤细胞显示 B 细胞表型（CD20+、CD79+），有 EBV 感染证据（EBER-ISH+），但 HHV8（LANA-1）阴性。鉴定了单克隆 IG 基因重排。BCL2、BCL6和MYC基因没有重排。尽管细胞形态学具有侵袭性，但在 8 个月的随访后，患者在 4 个周期的 R-CHOP 后完全缓解。文献报道了在达沙替尼治疗 CML 的情况下发生的其他 4 例大 B 细胞积液淋巴瘤病例。4例为HHV8阴性，1例为EBV阳性。四名患者中的三名经历了良性临床病程，这与 HHV8 阳性原发性渗出性淋巴瘤 (PEL) 形成鲜明对比。在接受 TKI 的患者中，这些基于积液的 B 细胞淋巴增殖的发展机制尚未完全阐明。在 CML 情况下 TKI 治疗期间的急性或复发性积液应进行细胞学检查以排除克隆性 B 细胞淋巴增殖。