Anatomical Pathology, PathWest Laboratory Medicine, QEII Medical Centre, Nedlands, WA, Australia.
Anatomical Pathology, PathWest Laboratory Medicine, QEII Medical Centre, Nedlands, WA, Australia; University of Western Australia, School of Pathology and Laboratory Medicine, Nedlands, WA, Australia.
Pathology. 2020 Jan;52(1):128-141. doi: 10.1016/j.pathol.2019.10.001. Epub 2019 Nov 11.
T- and NK-cell lymphoproliferative disorders of the gastrointestinal (GI) tract are uncommon, but are important to recognise as there may be morphological and immunophenotypic overlap between lymphoid lesions with vastly different clinical outcomes. Recent data have led to the reclassification of some lymphomas and inclusion of new entities in the 2016 revision of World Health Organization (WHO) classification of lymphoid neoplasms. It has become clear that enteropathy associated T-cell lymphoma (EATL), formerly thought to be composed of two subtypes known as type I and type II, are distinct entities. Type I EATL is now simply classified as EATL; it is strongly associated with coeliac disease and occurs mainly in Western populations. Type II EATL has been renamed monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL); it shows no definite association with coeliac disease and occurs worldwide with a predominance in Asian populations. There is also a group of aggressive intestinal T-cell lymphomas which do not meet criteria for EATL, MEITL, extranodal NK/T-cell lymphoma of nasal type or anaplastic large cell lymphoma. These neoplasms are now designated intestinal T-cell lymphoma, not otherwise specified. Indolent T-cell lymphoproliferative disorder of the GI tract has been included as a provisional entity in the most recent WHO classification. It is a clonal T-cell lymphoproliferative disorder (CD4+ or CD8+) with an indolent clinical course. Finally, benign NK-cell proliferations of the GI tract, variably designated 'NK-cell enteropathy' and 'lymphomatoid gastropathy' have also been recognised in the last two decades but have not been included in the WHO classification as their neoplastic nature is not established. This review covers the aforementioned lymphoid proliferations, emphasising their salient clinicopathological features and genetic abnormalities. It also provides practical insights into resolving difficult differential diagnoses in daily surgical pathology practice.
胃肠道（GI）的 T 细胞和 NK 细胞淋巴增生性疾病并不常见，但认识到这些疾病很重要，因为具有不同临床结果的淋巴病变之间可能存在形态和免疫表型重叠。最近的数据导致一些淋巴瘤的重新分类，并在 2016 年世界卫生组织（WHO）淋巴肿瘤分类修订版中纳入了新的实体。已经清楚的是，以前认为由两种亚型（I 型和 II 型）组成的肠病相关 T 细胞淋巴瘤（EATL）实际上是不同的实体。I 型 EATL 现在简单地被归类为 EATL；它与乳糜泻密切相关，主要发生在西方国家。II 型 EATL 已更名为单形上皮嗜性肠 T 细胞淋巴瘤（MEITL）；它与乳糜泻没有明确的关联，在全球范围内发生，以亚洲人群为主。还有一组侵袭性肠 T 细胞淋巴瘤不符合 EATL、MEITL、结外 NK/T 细胞淋巴瘤鼻型或间变性大细胞淋巴瘤的标准。这些肿瘤现在被指定为未特指的肠 T 细胞淋巴瘤。最近的 WHO 分类中还纳入了一种胃肠道惰性 T 细胞淋巴增生性疾病，作为暂定实体。它是一种克隆性 T 细胞淋巴增生性疾病（CD4+或 CD8+），具有惰性的临床病程。最后，在过去的二十年中，胃肠道的良性 NK 细胞增生也已被认识到，其不同的命名为“NK 细胞肠病”和“淋巴瘤性胃炎”，但由于其肿瘤性质尚未确定，尚未被纳入 WHO 分类。这篇综述涵盖了上述淋巴增生性疾病，强调了它们的显著临床病理特征和遗传异常。它还为在日常外科病理学实践中解决困难的鉴别诊断提供了实用的见解。
