Furlan Karina, Miller Ira, Mahon Brett, Ocampo Gonzalez Fernando A, Ward Nicholas
Department of Pathology, Rush University Medical Center, 1750 W Harrison St, 5th floor, Chicago, IL 60612, USA.
Case Rep Pathol. 2020 Dec 28;2020:8875547. doi: 10.1155/2020/8875547. eCollection 2020.
Plasmablastic lymphoma (PBL) is an aggressive high-grade B cell lymphoma, considered a variant of diffuse large B cell lymphoma with approximately 75% mortality within 6-7 months. We describe an unusual case of PBL arising as a maxillary mass in an HIV-negative, nontransplanted 78-year-old female. Histologic examination revealed a diffuse infiltrate of anaplastic appearing cells exhibiting plasmablastic morphology with an adjacent contiguous infiltrate of mature appearing plasma cells. The PBL and mature plasma cell components both demonstrated an immunophenotype of CD20(-), CD38(+), and CD138(+). The two populations differed by the PBL featuring a high proliferation rate by Ki-67 (95%) with coexpression of both c-MYC and EBV, while the mature plasma cell component featured a low proliferation rate by Ki-67 (5%) without coexpression of c-MYC or EBV. Kappa/lambda staining demonstrated lambda light chain restriction involving the PBL, while the mature plasma cell infiltrate revealed kappa light chain restriction. Our findings describe the rare association of PBL with a synchronous distinct population of mature plasma cells exhibiting opposite light chain restriction.
浆母细胞性淋巴瘤（PBL）是一种侵袭性高级别B细胞淋巴瘤，被认为是弥漫性大B细胞淋巴瘤的一种变异型，约75%的患者会在6至7个月内死亡。我们描述了一例罕见的PBL病例，该病例发生在一名78岁、HIV阴性、未接受过移植的女性患者的上颌骨肿块中。组织学检查显示，间变性细胞呈弥漫性浸润，表现为浆母细胞形态，同时伴有相邻的成熟浆细胞连续浸润。PBL和成熟浆细胞成分均表现出CD20（-）、CD38（+）和CD138（+）的免疫表型。这两个细胞群体的差异在于，PBL的Ki-67增殖率较高（约95%），同时c-MYC和EBV共表达，而成熟浆细胞成分的Ki-67增殖率较低（约5%），且不伴有c-MYC或EBV共表达。κ/λ染色显示PBL存在λ轻链限制，而成熟浆细胞浸润则显示κ轻链限制。我们的研究结果描述了PBL与同步出现的、具有相反轻链限制的成熟浆细胞独特群体之间的罕见关联。
