Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
Cancer Cytopathol. 2013 Nov;121(11):661-9. doi: 10.1002/cncy.21311. Epub 2013 Jun 13.
Primary effusion lymphoma (PEL) is a rare subtype of large B-cell lymphoma that arises in body cavities without detectable tumor masses. PEL is universally associated with Kaposi sarcoma herpesvirus (KSHV)/human herpesvirus-8 (HHV8). Despite overlapping features, KSHV/HHV8-negative effusion-based lymphoma is a distinct entity from PEL. To date, 52 cases have been reported. The authors report 3 additional cases received in their laboratory from 2007 to 2012.
Clinical data, cytomorphologic features, and immunophenotypic features of the 3 cases were described and compared with those reported in the literature.
The cells in HHV8-negative effusion lymphoma commonly revealed large cell, immunoblastic morphology and B-cell immunophenotype. The 3 cases demonstrated cytomorphologic and immunophenotypic variability. Cytomorphologically, 1 case contained large, highly atypical cells with a moderate amount of cytoplasm, round nucleus, coarsely granular chromatin, and a single macronucleolus. The other 2 cases had medium to large atypical cells with high nuclear-to-cytoplasmic ratios, slightly irregular to cleaved nuclei, and multiple conspicuous nucleoli. One case had a null phenotype with aberrant cytokeratin expression. B-cell phenotype was established by clonal immunoglobulin heavy-chain rearrangement using polymerase chain reaction, whereas the other 2 cases demonstrated a B-cell phenotype by flow cytometry and immunohistochemical staining. All 3 cases were negative for both HHV8 and Epstein-Barr virus.
HHV8-negative effusion lymphoma exhibits clinical, cytomorphologic, and immunophenotypic variability. Cases with a null-phenotype can be particularly challenging. When effusion lymphoma is suspected, ancillary tests are helpful. Moreover, HHV8 detection is critical in differentiating PEL and HHV8-negative effusion lymphoma, because they have overlapping features yet different prognoses.
原发性渗出性淋巴瘤（PEL）是一种罕见的大 B 细胞淋巴瘤亚型，发生在无明显肿瘤肿块的体腔中。PEL 普遍与卡波西肉瘤疱疹病毒（KSHV）/人类疱疹病毒 8（HHV8）相关。尽管具有重叠特征，但 KSHV/HHV8 阴性渗出性淋巴瘤是与 PEL 不同的实体。迄今为止，已有 52 例报告。作者报告了他们实验室在 2007 年至 2012 年期间收到的另外 3 例。
描述了 3 例病例的临床数据、细胞形态特征和免疫表型特征，并与文献报道的病例进行了比较。
HHV8 阴性渗出性淋巴瘤的细胞通常表现为大细胞、免疫母细胞形态和 B 细胞免疫表型。这 3 例病例表现出细胞形态和免疫表型的可变性。在细胞形态学上，1 例含有大量高度异型细胞，细胞质中等量，圆形核，粗糙颗粒状染色质，单个大核仁。另外 2 例有中到大的异型细胞，核质比高，核不规则至分叶，多个明显核仁。1 例表现为阴性表型，伴有异常细胞角蛋白表达。通过聚合酶链反应检测克隆性免疫球蛋白重链重排确立了 B 细胞表型，而另外 2 例通过流式细胞术和免疫组织化学染色显示了 B 细胞表型。所有 3 例均为 HHV8 和 Epstein-Barr 病毒阴性。
HHV8 阴性渗出性淋巴瘤表现出临床、细胞形态学和免疫表型的可变性。表现为阴性表型的病例可能特别具有挑战性。当怀疑渗出性淋巴瘤时，辅助检查是有帮助的。此外，HHV8 检测对于区分 PEL 和 HHV8 阴性渗出性淋巴瘤至关重要，因为它们具有重叠特征但预后不同。
