Department of Pathology, The University of Arkansas for Medical Sciences, Little Rock, AR.
Department of Pathology, MD Anderson Cancer Center, Houston, TX.
Adv Anat Pathol. 2019 Nov;26(6):371-389. doi: 10.1097/PAP.0000000000000248.
Primary mediastinal non-Hodgkin lymphomas (PM-NHLs) represent ∼5% of all non-Hodgkin lymphomas (NHLs) and comprise lymphomas of B-cell and T-cell origin. PM-NHLs are defined as involvement of mediastinal lymph nodes, thymus, and/or mediastinal organs (heart, lung, pleura, pericardium) by NHL without evidence of systemic disease at presentation. The clinical scenario is variable and depends on the lymphoma subtype. The radiologic presentation is also variable ranging from a mediastinal mass with or without superior vena cava syndrome, a pleural or a cardiac mass associated with effusion, or as an effusion only. The diagnosis of PM-NHLs can only be established by microscopic evaluation, and therefore, general pathologists should be aware of these tumors and familiar with their diagnostic approach. The most common anterior mediastinal NHLs (90% to 95%) are primary mediastinal (PM) large B-cell lymphoma and T-lymphoblastic lymphoma. Thymic marginal zone lymphoma and mediastinal gray zone lymphoma are very rare. The remainder PM-NHLs involving middle or posterior mediastinum include diffuse large B-cell lymphoma (DLBCL) and rare cases of T-cell lymphoma, including anaplastic large cell lymphoma and breast implant-associated anaplastic large cell lymphoma extending to the anterior mediastinum. Primary pleural and cardiac NHLs are mostly DLBCLs. Other rare subtypes of PM-NHLs include DLBCL associated with chronic inflammation/pyothorax-associated lymphoma, fibrin-associated DLBCL (both Epstein-Barr virus positive), and pleural and/or pericardial primary effusion lymphoma (human herpesvirus-8 positive/Epstein-Barr virus positive). We review the historical aspects, epidemiology, clinicoradiologic features, histopathology, immunohistochemistry, differential diagnosis, and relevant cytogenetic and molecular features of the remaining mediastinal B-cell lymphomas, including primary thymic marginal zone lymphoma of the mucosa-associated lymphoid tissue type, other PM small B-cell lymphomas, PM plasmacytoma, and the most relevant PM T-cell lymphomas.
原发性纵隔非霍奇金淋巴瘤（PM-NHL）占所有非霍奇金淋巴瘤（NHL）的约 5%，包括 B 细胞和 T 细胞来源的淋巴瘤。PM-NHL 定义为 NHL 累及纵隔淋巴结、胸腺和/或纵隔器官（心脏、肺、胸膜、心包），而在初次就诊时无全身疾病的证据。临床情况因淋巴瘤亚型而异。放射学表现也多种多样，从纵隔肿块伴或不伴上腔静脉综合征、胸膜或心脏肿块伴积液，或仅为积液。PM-NHL 的诊断只能通过显微镜评估来确定，因此，普通病理学家应该了解这些肿瘤，并熟悉其诊断方法。最常见的前纵隔 NHL（90%至 95%）是原发性纵隔（PM）大 B 细胞淋巴瘤和 T 淋巴母细胞淋巴瘤。胸腺瘤和纵隔灰区淋巴瘤非常罕见。其余累及中后纵隔的 PM-NHL 包括弥漫性大 B 细胞淋巴瘤（DLBCL）和罕见的 T 细胞淋巴瘤，包括间变大细胞淋巴瘤和乳房植入物相关间变大细胞淋巴瘤延伸至前纵隔。原发性胸膜和心脏 NHL 主要为 DLBCL。其他罕见的 PM-NHL 亚型包括与慢性炎症/脓胸相关的淋巴瘤相关的 DLBCL、纤维相关的 DLBCL（均为 EBV 阳性）以及胸膜和/或心包原发性渗出性淋巴瘤（HHV-8 阳性/EBV 阳性）。我们回顾了其余纵隔 B 细胞淋巴瘤的历史方面、流行病学、临床影像学特征、组织病理学、免疫组织化学、鉴别诊断以及相关细胞遗传学和分子特征，包括黏膜相关淋巴组织型原发性胸腺边缘区淋巴瘤、其他 PM 小 B 细胞淋巴瘤、PM 浆细胞瘤和最相关的 PM T 细胞淋巴瘤。
