黏膜相关淋巴组织淋巴瘤

黏膜相关淋巴组织淋巴瘤 (ｍｕｃｏｓａａｓｓｏｃｉａｔｅｄｌｙｍｐｈｏｉｄｔｉｓｓｕｅｌｙｍｐｈｏｍａ,ＭＡＬＴ ＭＬ )起初是指起源在胃肠道ＭＡＬＴ的一种Ｂ细胞淋巴瘤。早期的观点认为胃肠道的淋巴瘤基本都是ＭＡＬＴ ＭＬ ,并且是低度恶性的淋巴瘤 ,后来认识到有高度恶性的ＭＡＬＴ ＭＬ。但目前认为全身各处均可发生 ,无论有无ＭＡＬＴ ,只要有获得性ＭＡＬＴ/Ｐｅｙｅｒ小结样结构即可发生 ,小结中心为生发中心 ,周围有套细胞和边缘区细胞 ,故在黏膜层既可发生ＭＡＬＴ ＭＬ ,也可发生黏膜滤泡性淋巴瘤和黏膜套细胞淋巴瘤 ,因此…     

黏膜相关淋巴组织淋巴瘤诊断标准

黏膜相关淋巴组织淋巴瘤(mucosa associated lymphoid tissue lymphoma,MALT-ML)的命名及诊断标准已在1997年WHO淋巴组织肿瘤新分类中确定[1],发表的有关文献也日渐增多.由于病理学工作者可能对此认识不足,导致误诊、漏诊者屡见不鲜,给患者带来不良后果.为此作者综合相关文献结合自己的多年工作体会将MALT-ML的概念与诊断标准作一介绍,供同道参考.     

黏膜相关淋巴组织淋巴瘤

在呼吸道、消化道、泌尿生殖道黏膜及黏膜下存在无结构、散在的淋巴细胞。有结构的黏膜相关淋巴组织主要存在于回肠末端及支气管黏膜下。其最具特征的结构为Peyer斑（Peyer’s patches,1667年首先由Peyer描述而得名）。有结构的黏膜相关淋巴组织与淋巴结的淋巴组织结构相似,但无包膜。单个Peyer斑呈卵圆形,由生发中心、帽区及宽阔的边缘带B细胞构成。其外围为相邻的副皮质区样的T细胞区。边缘区的B细胞可进入覆盖Peyer斑的圆顶区上皮内（这些上皮内的B细胞与小肠其他部位上皮内的T细胞有别）。此外,固有膜内的浆细胞也是黏膜相关淋巴组织的一个组成成分。概括起来,     

黏膜相关淋巴组织淋巴瘤和凋亡相关基因

细胞凋亡受抑是黏膜相关淋巴组织(mucosa-associated lymphoid tissue, MALT)淋巴瘤发生的重要机制。MALT淋巴瘤凋亡相关基因的研究逐渐引起了重视。API2-MALT1融合基因和bcl-10过表达分别激活NF-κB,以NF-κB激活为核心,涉及到p53,Fas,API2,MALT1等凋亡相关基因,导致细胞凋亡受抑。     

黏膜相关淋巴细胞淋巴瘤诊断标准

黏膜相关淋巴组织淋巴瘤 (ｍｕｃｏｓａａｓｓｏｃｉａｔｅｄｌｙｍｐｈｏｉｄｔｉｓｓｕｅｌｙｍｐｈｏｍａ,ＭＡＬＴ ＭＬ)的命名及诊断标准已在 1997年ＷＨＯ淋巴组织肿瘤新分类中确定〔1〕,发表的有关文献也日渐增多。由于病理学工作者可能对此认识不足 ,导致误诊、漏诊者屡见不鲜 ,给患者带来不良后果。为此作者综合相关文献结合自己的多年工作体会将ＭＡＬＴ ＭＬ的概念与诊断标准作一介绍 ,供同道参考。1　概念1983年Ｉｓａａｃｓｏｎ与Ｗｉｇｈｔ教授首先提出ＭＡＬＴ ＭＬ初步概念〔2〕,当时主要是指胃、肠道黏膜淋巴组织低度恶性…     

眼部原发性黏膜相关淋巴组织结外边缘区B细胞淋巴瘤的临床病理分析

近年来眼部淋巴瘤日益多见,其中眼附属器淋巴瘤占老年人眼眶原发性恶性肿瘤的首位。根据2001年WHO恶性淋巴瘤分类诊断标准,眼附属器淋巴瘤大多属于黏膜相关淋巴组织结外边缘区B细胞淋巴瘤（MALT淋巴瘤）,其临床和组织病明学表现、治疗及预后均有其特殊性。我们对眼部MALT淋巴瘤的临床和病理资料进行了回顾性分析。     

胸腺原发黏膜相关淋巴组织淋巴瘤及淋巴上皮性涎腺炎样胸腺增生的临床病理分析

目的探讨胸腺原发黏膜相关淋巴组织(mucosa associated lymphoid tissue,MALT)淋巴瘤和淋巴上皮性涎腺炎(lymphoepithelial sialadenitis,LESA)样胸腺增生的临床病理学特征、两者相关性及鉴别诊断。方法分析3例胸腺MALT淋巴瘤和1例LESA样胸腺增生的临床病理学和免疫表型特征,并复习相关文献。结果 3例胸腺MALT淋巴瘤,其中2例伴Sj9gren综合征;镜下胸腺正常结构损毁,增生的淋巴滤泡间可见肿瘤性淋巴样细胞浸润伴明显的淋巴上皮病变,以中心细胞样和单核样B细胞形态为主。瘤细胞表达CD20、PAX-5和BCL-2,其中1例伴显著浆细胞分化者Lambda轻链限制性表达。3例胸腺MALT淋巴瘤免疫球蛋白(immunoglobulin,Ig)基因检测均示单克隆性重排。LESA样胸腺增生镜下胸腺分叶状结构大体尚存,可见包含增生滤泡的丰富淋巴细胞浸润,胸腺上皮增生伴显著淋巴上皮病变,未见有单核样B细胞形态。免疫组化染色示增生淋巴组织由B和T细胞混合;Ig基因重排检测示多克隆性增生。结论 LESA样胸腺增生和胸腺MALT淋巴瘤均是胸腺少见的淋巴增生性病变,两者具有相似的组织学和免疫表型特征;结合基因重排技术详细分析两者的鉴别要点,有助于鉴别。     

肺黏膜相关淋巴组织边缘区B细胞淋巴瘤及良性淋巴组织增生性疾病的临床病理分析

目的 研究肺原发性黏膜相关淋巴组织边缘区B细胞(MALT)淋巴瘤及良性淋巴组织增生性疾病的临床病理形态、免疫组织化学表型和B细胞重链基因重排,比较肺MALT淋巴瘤和良性淋巴组织增生性疾病的差异.方法 回顾性的分析原发性肺MALT淋巴瘤13例,7例肺良性淋巴组织增生性疾病资料.对标本行常规HE染色,EnVision免疫组织化学染色(抗体包括AE1/AE3、CD20、CD79α、CD3、CD5、CD10、CD21、bel-2、bcl-6、cyclinD-1)及免疫球蛋白重链IgH基因重排检测.结果 13例肺MALT淋巴瘤,细胞成分多样,分别由不同比例的小淋巴细胞样细胞、中心细胞样细胞、单核样B细胞组成,常伴有浆细胞分化.肿瘤细胞以弥漫性和滤泡边缘区排列为主,常见反应性淋巴滤泡和滤泡中心的植入.肿瘤细胞呈串珠状直接侵犯肺泡间隔和沿支气管血管束向周边及肺膜扩散.MALT淋巴瘤中,均未见坏死.9例可见肿瘤细胞侵犯血管壁,6例可见胸膜累及,2例肺门淋巴结侵犯.9例肺MALT淋巴瘤可见淋巴上皮样病变,免疫组织化学显示上皮细胞内的淋巴细胞CD20阳性,CD3阴性.7例肺良性淋巴组织增生性疾病,2例可见淋巴上皮样病变,免疫组织化学显示,其淋巴上皮样病变内的淋巴细胞,部分CD20阳性,部分CD3阳性.9例肺MALT淋巴瘤进行了免疫球蛋白重链IgH基因重排,8例阳性;7例良性淋巴组织增生性疾病均为阴性.结论 肺MALT淋巴瘤在细胞组成和排列上与其他部位结外MALT淋巴瘤相同,肿瘤细胞呈串珠状直接侵犯肺泡间隔和沿支气管血管束向周边及肺膜扩散.在肺内淋巴上皮样病变常见于MALT淋巴瘤,并有助于诊断,但并非其特异性病变,一些肺的反应性淋巴组织增生也可出现,用免疫组织化学有助于区别两种病变.免疫球蛋白重链IgH基因重排可以帮助鉴别肺MALT淋巴瘤和良性淋巴组织增生性疾病.     

胃黏膜相关淋巴组织淋巴瘤的诊治进展

目的：综述胃黏膜相关淋巴组织（macosa—associatedlymphoidtissue,MALT）淋巴瘤的临床诊治现状与存在的问题,并展望其前景。方法：广泛查阅近年来有关胃MALT淋巴瘤的临床诊治的相关文献,并作进一步综合分析。结果：胃MALT淋巴瘤是一种临床较为少见的胃恶性肿瘤,长期以来对其诊断治疗一直存在争议。结论：联合应用X线胃肠气钡双重造影、CT、胃镜、及内镜超声等多种检查手段可明显提高诊断的阳性率;传统的观点认为手术是治愈的最主要手段,但随着对幽门螺旋杆菌（Hpyloft）感染与该病发病机制的认识提高,这一观点不断受到冲击。     

Mucosa-associated lymphoid tissue lymphoma in conjunctiva

A case of primary mucosa-associated lymphoid tissue (MALT) lymphoma (marginal zone B-cell lymphoma of MALT according to WHO classification) in conjunctiva, which presented as a slowly growing salmon-colored mass at limbus of left eye is reported. Histological examination revealed a diffuse low-grade lymphoma. Immunohistochemical analysis using monoclonal antibodies showed that the tumor cells are leukocyte common antigen (CD45)+, CD20+, CD3-, CD5-, CD10- and CD43-, which confirmed the B-cell lineage of lymphoma. The case is being reported for its rarity and clinical importance of recognizing such cases because of excellent prognosis.     

Mucosa-associated lymphoid tissue lymphoma coexisting with epithelioid granulomas in the stomach of a patient with systemic sarcoidosis

Malignant lymphoma arising in the stomach of a 23-year-old Japanem man with systemic sarcoldosis is presented. The patient was followed because of systemic sarcoidosis involving the lungs, eyes, and lymph nodes. Biopsy specimens from the stomach were repeated because of recurrent eplgastraigia and multiple ulcerations. Some of the specimens revealed epithelloid granuiomas with no caseous necrosis, which confirmed gastric involvement of sarcoidosis. Three years after the initial diagnosis, biopsy specimens taken from the stomach were diagnosed as malignant lymphoma of the large cell type. The resected stomach revealed muiticentric mucosa-associated type malignant lymphoma of low-grade B cell type, with foci of high-grade transformation coexisting with numerous epithelioid granulomas with no caseous necrosis. Epithelloid granulomas were observed in all the respected lymph nodes, liver, and appendix, which had been obtained at operation, whereas malignant lymphoma was limited to the stomach. Hellcobacter pylori (H. pylori ) infection was also observed in the stomach. Consequently, the present report is a rare case of coexistence of malignant lymphoma and involvement of sarcoidosis in the stomach. Both H. pylori infection and active sarcoid noduies may play a role in the development of malignant lymphoma, although the exact mechanism remains undear.     

Mucosa-associated lymphoid tissue lymphoma of the esophagus coexistent with bronchus-associated lymphoid tissue lymphoma of the lung

Non-Hodgkin's lymphoma very rarely involves the esophagus, occurring in less than 1% of patients with gastrointestinal lymphoma. A few cases of mucosa-associated lymphoid tissue (MALT) lymphoma of the esophagus have been reported in the English literature. To our knowledge, there has been no report of MALT lymphoma of the esophagus coexistent with bronchus-associated lymphoid tissue lymphoma (BALT) of the lung. This report details the radiological and clinical findings of this first concurrent case.     

Mucosa-associated lymphoid tissue lymphoma in the conjunctiva of a child

Marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT) occurring in the conjunctiva has yet not been described in pediatric patients. We present a case of a 10-year-old girl with a MALT lymphoma involving the conjunctiva. The tumor consisted of plasma cells and marginal zone cells with discrete epitheliotropism. Immunohistochemical studies revealed positivity for CD20 and cytoplasmic immunoglobulin light chain restriction. Polymerase chain reaction-based molecular analysis of the infiltrate showed a monoclonal rearrangement for the hypervariable complimentary determining region III immunoglobulin region; whereas, a polyclonal pattern was seen for the T-cell receptor chain. Extensive further examination, including molecular techniques, revealed that the lymphoma was restricted to the conjunctiva (stage IA) and was not associated with any specific infection. The patient was treated with surgery and additional local cryotherapy. After 15 months of follow-up, the patient remains in complete remission.     

Mucosa-associated lymphoid tissue lymphoma: molecular pathogenesis and clinicopathological significance

Mucosa-associated lymphoid tissue (MALT) lymphoma is a low-grade tumor closely associated with chronic inflammation such as that of Helicobacter pylori gastritis, Sjogren's syndrome, and Hashimoto's thyroiditis. Tumor regression by H. pylori eradication alone is well known in gastric MALT lymphoma, but some tumors occur in the absence of pre-existing chronic inflammation. The understanding of MALT lymphoma biology has significantly improved, and recurrent cytogenetic alterations have been detected. These include the trisomies 3 and 18, and the translocations t(11;18)(q21;q21), t(1;14)(p22;q32), t(14;18)(q32;q21), and t(3;14)(p14.1;q32). At least some of these alterations result in the constitutive activation of the nuclear factor (NF)-kappaB pathway, and may exert anti-apoptotic action. Apoptosis inhibitor 2-MALT lymphoma-associated translocation 1 (API12-MALT1) fusion, resulting from t(11;18)(q21;q21), is specific to, and is the most common in, MALT lymphomas, and its clinicopathological significance has been studied extensively. The focus of the present review is on the recent progress made in elucidating MALT lymphomagenesis and its clinicopathological impact, especially in terms of the effect of API2-MALT1 fusion on this unique tumor.     

Mucosa-associated lymphoid tissue of the thymus hyperplasia vs lymphoma.

In the thymus, the relationship between lymphofollicular hyperplasia and mucosa-associated lymphoid tissue (MALT)-type lymphoma is uncertain. We analyzed 14 cases with a diagnosis of thymic follicular hyperplasia in patients with connective tissue disease (n = 2), myasthenia gravis (n = 11), or both (n = 1). In 11 cases, well-defined reactive lymphoid follicles were surrounded by a continuous layer of medullary epithelial cells. A polyclonal rearrangement of the immunoglobulin heavy chain gene (IgH) was observed. In 3 cases, ill-defined lymphoid follicles with sheets of centrocytic-like B cells disrupting the medullary cytokeratin epithelial network were observed on certain sections. These cells expressed the phenotypic features of memory B cells with CD20, CD79a, and bcl-2 positivity and CD5, CD10, CD23, and bcl-6 negativity, and a monoclonal rearrangement of the IgH gene was detected. Appropriate sampling, cytokeratin staining, and molecular analyses may help to identify early MALT-type lymphoma developing in the setting of thymic lymphofollicular hyperplasia.     

乳腺粘膜相关型淋巴瘤临床病理观察

目的：探讨乳腺粘膜相关性淋巴瘤（MALT-ML）的病理特征。方法：对4例乳腺MALT-ML的手术根治及（或）活检标本做常规石蜡切片、HE染色和免疫组化ABC法标记。结果：4例乳腺MALT-ML中2例为CCL细胞型,1例为CCL细胞型向母细胞样转化,另1例炎单核样B细胞型。4例均显示B细胞单克隆性及滤泡克隆化和淋巴上皮病变。结论：乳腺MALT-ML有与其他部位MALT-ML相似的形态特征。     

Mucosa-associated lymphoid tissue (MALT) lymphoma: a practical guide for pathologists

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is the third most common non-Hodgkin lymphoma subtype, accounting for around 6-8% of all non-Hodgkin lymphomas in the Western hemisphere. Although MALT lymphomas are clinically indolent, the disease is typically chronic, requiring long-term clinical surveillance and, often, repeated biopsies. Pathologists thus play a central role in the diagnosis and management of these patients. The optimal diagnosis and management of a MALT lymphoma requires careful integration of morphological, immunohistochemical and molecular information, together with close cooperation with the clinician treating the patient. This review discusses recent developments in the molecular pathogenesis of MALT lymphoma and provides strategies for integrating this information into daily pathological practice.