具有浆母细胞特征的B细胞肿瘤3例临床病理学观察

B cell neoplasms with plasmablastic differentiation: a clinicopathological analysis

目的探讨具有浆母细胞特征的B细胞肿瘤的临床病理特点、组织学特征、诊断及鉴别诊断。方法应用光镜观察、免疫组化染色、原位杂交对3例少见的具有浆母细胞特点的B细胞肿瘤[浆母细胞性淋巴瘤(plasmablastic lymphoma,PBL)、浆母细胞性浆细胞骨髓瘤(plasmablastic plasma cell myeloma,PPCM)和间变性浆细胞骨髓瘤(anaplastic plasma cell myeloma,APCM)]进行临床病理学分析。结果 PBL患者具有免疫异常的病史,PPCM和APCM临床上有多发溶骨性破坏,血清免疫球蛋白升高,PBL、PPCM和APCM均具有浆母细胞的特征,PBL和APCM还可见免疫母细胞样肿瘤细胞。3例免疫组化均表达CD38、CD138、MUM1,不表达CD20、PAX5,Ki-67增殖指数高,EBER均阴性。其中1例浆细胞骨髓瘤(plasma cell myeloma,PCM)由分化成熟的普通型进展为浆母细胞型。结论 PBL、PPCM和APCM都具有浆母细胞的特征,三者组织形态学和免疫表型均相似,鉴别诊断困难,明确鉴别PBL和PCM对指导临床治疗具有重要意义,诊断应紧密结合临床。PCM可向高度恶性进展。

Purpose To study the clinical and histopathologic features, diagnosis and differential diagnosis of B cell neoplasms with plasmablastic differentiation. Methods Three rare cases of B cell neoplasms with plasmablastic differentiation （ plasmablastic lymphoma, PBL, plasmablastic plasma cell myeloma, PPCM, anaplastic plasma cell myeloma, APCM） were studied by microscopy, immunohistoehemistry and in situ hybridization, with review of related literature. Results Plasmablasts were seen in PBL, PPCM and APCM. The cases were all positive for CD38, CD138 and MUM1, but negative for CD20 and PAX5 and with high index of Ki-67. PBL patient had a history of immunodeficiency, PPCM and APCM patients had multiple lytic bone lesions and high level of serum immunoglobulin. Immunoblast-like cells were present in both PBL and APCM cases. EBER were negative in the three cases. The case of PPCM was pro- gressed from usual type of plasma cell myeloma. Conclusions PBL, PPCM and APCM all have the features of plasmablasts, whose histology and immunophenotype are similar, but differential diagnosis is difficult. The definite diagnosis of PBL and plasma cell myeloma is important for clinical therapy, and close combination with clinical features is necessary for pathological diagnosis. Plasma cell myeloma can progress into high grade neoplasm.