Primary non-Hodgkin's lymphoma of the intestine: a morphological, immunohistochemical and clinical study of 31 Chinese cases

Thirty-one cases of primary non-Hodgkin's lymphoma of the intestine were investigated. Twenty-one were of B-cell and 10 of T-cell origin. The B-cell lymphomas comprised two cases of low-grade B-cell lymphoma of mucosaassociated lymphoid tissue (MALT), one of centroblastic/centrocytic type, three of high-grade B-cell lymphoma coexisting with a low-grade B-cell lymphoma of MALT, nine of centroblastic, three of immunoblastic and three of Burkitt type. Of the T-cell lymphomas, eight were of pleomorphic medium-to large-sized cell type and two of large cell anaplastic type. All the B-cell lymphomas expressed CD20 (L26) and/or Ki-B5; in six there was monotypic immunoglobulin light chain restriction. Membrane positivity for CD45RO (UCHL1) was observed in the 10 cases of T-cell lymphoma, but the tumour cells did not express monocyte-macrophage markers. Clinically, the patients with T-cell lymphomas were usually young males with constitutional symptoms and their prognosis was significantly worse than those of patients with intestinal B-cell lymphoma.     

Gene rearrangement of bcl-1 and bcl-2 is confined to distinct subgroups of high-grade malignant B-cell lymphomas

The occurrence of bcl-1 and bcl-2 gene rearrangements was investigated in 37 cases of high-grade B-cell lymphomas. Bcl-2 rearrangement was detectable only in single cases of primary centroblastic lymphoma with a follicular growth pattern, whereas secondary centroblastic lymphomas evolving from a centroblastic–centrocytic lymphoma were positive in up to 60 per cent of the cases analysed. Bcl-1 rearrangement was found only in one case of immunoblastic B-cell lymphoma with a history of a pre-existing lymphoplasmacytoid immunocytoma. It is concluded that there may be a subgroup of centroblastic lymphomas with a biology similar to that of centroblastic–centrocytic lymphomas. The detection of bcl-1 rearrangement in high-grade lymphomas may indicate a secondary high-grade lymphoma.     

A genotypic study of low grade B-cell lymphomas, including lymphomas of mucosa associated lymphoid tissue (MALT)

Genotypic analysis has led to the implication of certain oncogenes in the pathogenesis of specific groups of non-Hodgkin's lymphoma. Rearrangements of c-myc are associated with Burkitt's lymphoma and of bcl-2 with centroblastic/centrocytic lymphoma. Rearrangement of bcl-1 has yet to be associated with a specific group of lymphoma. In this study DNA from 62 cases of low grade B-cell lymphoma, classified using the Kiel classification, were analysed by Southern blotting and hybridization with probes to bcl-1, bcl-2, and c-myc. Rearrangements of bcl-2 were found in a proportion of centroblastic/centrocytic lymphoma comparable to other published studies. Rearrangement of c-myc was not found in any case studied. Bcl-1 rearrangement was found in 2/9 cases of B-CLL, and 3/6 cases of centrocytic lymphoma. This incidence of bcl-1 rearrangement in centrocytic lymphoma suggests that it is a characteristic change. No rearrangement of bcl-1, bcl-2 or c-myc was found in any case of lymphoma of mucosa associated lymphoid tissue (MALT), providing further evidence that, in spite of having a similar morphology to some other groups of low grade B-cell lymphoma, lymphomas of MALT comprise a distinct entity.     

De novo CD5-positive and Richter's syndrome-associated diffuse large B cell lymphomas are genotypically distinct.

Diffuse large B cell lymphomas (DLBLs) represent a heterogeneous collection of aggressive non-Hodgkin's lymphomas that can arise either de novo or as a result of transformation from chronic lymphocytic leukemia, small lymphocytic lymphoma, follicular lymphomas, or lymphomas of mucosa-associated lymphoid tissue. A small percentage of DLBLs express the CD5 antigen. The majority of these cases have evolved from a pre-existing low grade non-Hodgkin's lymphoma (Richter's syndrome). However, we identified and characterized nine CD5-positive DLBLs in which the patients did not have a previous history or concomitant evidence of chronic lymphocytic leukemia, small lymphocytic lymphoma, follicular lymphoma, or mucosa-associated lymphoid tissue-associated non-Hodgkin's lymphoma, suggesting that they arose de novo. All nine cases expressed CD20 and monotypic immunoglobulin, all eight cases examined expressed CD19, CD22 and CD43, eight of the nine cases expressed HLA-DR, and two of eight cases expressed CD11c. None of the cases expressed CD3, CD10, CD11b, CD21, CD23 or CD30. CD5 expression by these cells was found to be identical to that of CD5-positive B cell chronic lymphocytic leukemia by quantitative polymerase chain reaction analysis of CD5 mRNA. These nine de novo CD5-positive DLBLs exhibited clonal immunoglobulin heavy and light chain gene rearrangements but lacked integration of the Epstein-Barr virus genome and structural alterations of the bcl-1, bcl-2, c-myc, H-ras, K-ras, and N-ras proto-oncogenes and the p53 tumor suppressor gene. However, bcl-6 proto-oncogene rearrangement, which is involved in chromosome band 3q27 aberrations, was found in four cases (44.4%). This is comparable with the frequency of bcl-6 gene rearrangement in CD5-negative DLBL. In contrast, bcl-6 gene rearrangement was absent in six cases of DLBL associated with Richter's syndrome. These findings suggest that de novo CD5-positive DLBLs are genotypically similar to CD5-negative DLBLs and may be pathogenetically distinct from the DLBLs associated with Richter's syndrome.     

MUC1 (EMA) is preferentially expressed by ALK positive anaplastic large cell lymphoma, in the normally glycosylated or only partly hypoglycosylated form.

AIMS: To investigate whether MUC1 mucin, a high molecular weight transmembrane glycoprotein, also known as epithelial membrane antigen (EMA), differs in its expression and degree of glycosylation between anaplastic large cell lymphoma (ALCL) and classic Hodgkin's disease (HD), and whether MUC1 immunostaining can be used to differentiate between CD30 positive large cell lymphomas. METHODS/RESULTS: Using five different monoclonal antibodies (E29/anti-EMA, DF3, 139H2, VU-4H5, and SM3) that distinguish between various MUC1 glycoforms, high MUC1 expression (50-95% of tumour cells positive) was found in 13 of 17 anaplastic lymphoma kinase (ALK) positive systemic nodal ALCLs, and in one of 20 cases of classic HD. Scattered or focal staining (< 25% of tumour cells) was seen in two additional ALK positive systemic ALCLs, two additional classic HD cases, and in three of 20 cases of ALK negative systemic nodal ALCL. Primary cutaneous ALCL showed no staining with the anti-MUC1 antibodies. Antibodies detecting hypoglycosylated MUC1 were found to be absent in all lymphomas (SM3) or present in only six of 15 ALK positive ALCLs (VU-4H5). CONCLUSIONS: MUC1 is preferentially expressed by a subtype of systemic nodal ALCL, characterised by ALK expression, but is found in only a few cases of classic HD and ALK negative ALCL. Therefore, although MUC1 could be used in a panel of markers for CD30 positive lymphomas, it is probably not a valuable tool to differentiate between ALK negative CD30 positive large cell lymphomas. Finally, the degree of MUC1 glycosylation in lymphomas is relatively high, compared with the aberrant hypoglycosylation found in adenocarcinomas.     

Morphological characteristics of malignant T-cell lymphomas in baboons

Fifteen cases of generalized peripheral T-cell non-Hodgkin's lymphoma in baboons were phenotyped immunologically and morphologically. Using the updated Kiel classification the cases included low-grade and high-grade lymphomas and low-grade lymphomas that had transformed into high-grade lymphomas. In the low-grade group there were seven cases of lymphocytic type, partly corresponding to chronic lymphocytic leukaemia of T type and to T-zone lymphoma in man. In addition there were four cases of prolymphocytic-lymphocytic type, which show large nodules (proliferation centres) and which have no equivalent in the Kiel classification. In four cases there was a progression to an immunoblastic lymphoma and in one case to a large cell anaplastic lymphoma. In addition, three cases of large cell anaplastic lymphoma without a low-grade component were found. Both the immunoblastic lymphomas and the large cell anaplastic lymphomas corresponded well with the same types in the Kiel classification. The cases of large cell anaplastic lymphoma were also CD30 positive. Most of these lymphomas were CD4 positive, but there were rare cases that were either CD8 positive, showed both CD4 and CD8 positivity or had lost both antigens. Antigens associated with cell activation were often revealed. All but one baboon had antibodies in the blood against the retrovirus STLV-1 (simian T-cell leukaemia virus 1), which is very similar to human T-cell leukaemia virus 1 (HTLV-1) in man. Despite this virological resemblance, the morphology of these T-cell lymphomas does not resemble that of the HTLV-1-positive Japanese T-cell lymphomas but is like that of the HTLV-1-negative European cases.     

Lacunar and reed-sternberg-like cells in follicular lymphomas are clonally related to the centrocytic and centroblastic cells as demonstrated by laser capture microdissection

Two cases of follicular lymphoma (FL) with numerous large cells resembling the lacunar and Hodgkin and Reed-Sternberg (HRS) cells of classic Hodgkin lymphoma were studied to determine clonal relationships between the HRS-like cells and centrocytic and centroblastic (CCCB) cells. In both cases, CCCB cells were typical of FL; CD45RB, CD20, CD10 and BCL-2 positive. In case 1, the HRS-like cells were positive for CD45RB, CD20, CD10, CD30, OCT2, and BOB.1 and negative for CD15 and bcl-2. In case 2, the HRS-like cells were positive for CD30, fascin, CD20, OCT2, and BOB.1 and negative for CD45RB, CD10, CD15, and bcl-2. CCCB and single HRS-like cells were isolated by laser capture microdissection followed by polymerase chain reaction amplification and sequencing of immunoglobulin heavy chain gene rearrangements. In both cases, identical sequences were obtained from CCCB and HRS-like cells. These findings confirm that although the HRS cells and CCCB cells in these cases demonstrate morphologic and immunophenotypic divergence, they share a common cell of origin. These cases further highlight the potential diagnostic pitfall presented by FL with HRS-like cells.     

Multiple lymphomatous polyposis of the gastrointestinal tract

Multiple lymphomatous polyposis (MLP) is a distinctive type of primary gastrointestinal lymphoma characterized by polypoid accumulations of lymphoma tissue involving long segments of the gastrointestinal tract. A study of four cases of MLP has shown a tendency for ileocaecal involvement and extra-abdominal dissemination. The lymphoma is of centrocytic type and exhibits a nodular pattern of variable degree. Trapping of reactive follicle centres with replacement of their mantle zones is characteristic. Immunohistochemical studies show a high concentration of monotypic SIg demonstrable in both cryostat and paraffin sections together with the other features of malignant lymphoma, centrocytic. The histological features of MLP bear a close resemblance to those of intermediate cell and mantle zone lymphoma, as described by American workers, which suggests that these two conditions and malignant lymphoma, centrocytic, are the same entity. In the gastrointestinal tract malignant lymphoma, centrocytic, produces a characteristic classic clinicopathological picture (MLP). In view of its less favourable prognosis it is important to distinguish MLP from other primary gastrointestinal lymphomas of follicle centre cell origin.     

Primary lymphoma of the liver: clinical and pathological features of 10 patients.

Nine out of 10 patients with primary lymphoma of the liver presented in a manner that did not suggest a tumour. The initial diagnoses were chronic active hepatitis in three cases and "granulomatous cholangitis", inflammatory pseudotumour, and anaplastic carcinoma in one case each. Moreover, extensive haemorrhagic necrosis in three cases initially suggested the Budd-Chiari syndrome. All the tumours were diffuse non-Hodgkin's lymphomas like the 50 cases reported previously, but they differed from most of these in that nine were of T cell phenotype. Five were pleomorphic small T cell, two T zone, and two T lymphoblastic lymphomas: only one was centrocytic and of B cell lineage. This report extends the range of clinical manifestations (diffuse hepatomegaly without a tumour), histological appearances (resemblance to chronic inflammatory or vascular liver diseases) and phenotype (of T cell lineage) of primary lymphoma of the liver: these features seemed to be related in this series. Recognition is important as prognosis remains favourable in appropriately treated cases. Although the appearances of the liver biopsy specimens may be difficult to interpret, the destructiveness of the infiltrate is an important clue to the diagnosis.     

儿童散发性伯基特淋巴瘤的分子遗传学特征分析

目的 研究儿童散发性伯基特淋巴瘤(BL)的分子遗传学特征及其诊断和鉴别诊断.方法 对64例儿童BL和6例儿童弥漫性大B细胞淋巴瘤(DLBCL)进行免疫组织化学染色(SP法)和荧光原位杂交(FISH)技术检测c-myc、bcl-2、bcl-6、IgH、myc/lgH及bcl-2/IgH基因重排的情况.根据细胞起源分类分为生发中心组(GC组)、生发中心晚期组(late-GC组)、生发中心后组(post-GC组).结果 BL表达CD20(64例)、CD10(63例)、bcl-6(62例)、MUM1(15例)、bcl-2(0例).GC组49例(76.6%)、late-GC组14例(21.9%)、post-GC组1例(1.6%).c-myc基因断裂54例(93.1%);IgH基因断裂48例(82.8%);c-myc与IgH基因同时断裂并myc/IgH基因易位46例(85.2%);c-myc基因断裂、IgH和myc/IgH基因正常4例(7.4%);c-myc、IgH和myc/IgH基因均正常4例(7.4%);bcl-2基因正常61例(100%);bcl-6基因正常59例,1例断裂并扩增具有BL的病理形态和免疫表型特征,同时具有c-myc基因断裂,将病理诊断修改为介于DLBCL和BL之间的未分类的B细胞淋巴瘤(DLBCL/BL).6例DLBCL中c-myc基因断裂2例;2例bcl-6基因扩增,其中1例伴c-myc基因断裂;无bcl-2/IgH基因重排.结论 儿童散发性BL大多数来源于生发中心B细胞,c-myc基因的断裂是其主要分子遗传学改变.应用FISH进行多基因的检测,有助于提高儿童BL的诊断和鉴别诊断水平.     

Immunophenotypic and genotypic markers of follicular center cell neoplasia in diffuse large B-cell lymphomas.

Diffuse large B-cell lymphomas (DLBCL) are a biologically and clinically heterogeneous entity. Although some DLBCL represent transformation of follicular lymphomas (FL), the proportion that is of follicular center cell (FCC) origin remains uncertain. Immunophenotypic and genotypic markers used to suggest a FCC origin for a lymphoma (bcl-6 and CD10 expression, lack of CD138 expression, bcl-2 rearrangements [R]) or to subdivide DLBCL (bcl-2 expression, bcl-6 R) were therefore investigated in 22 FL and 44 DLBCL using paraffin section immunostains and Southern blot/polymerase chain reaction analysis. All FL tested were bcl-6+ (19) and CD138- (22) with 16/19 also bcl-2 and CD10+ (classic phenotype), one bcl2+, CD10- (grade III) and two bcl2-, CD10+ (grade II or III). Bcl-2R was identified in 4/5 FL-GrI, 3/6 FL-GrII, and 1/3 FL-GrIII. Bcl-6R was found in 0/5, 2/4, and 0/3 FL, respectively. All but 3/41 DLBCL were bcl-6+ with 17/37 also bcl-2+ and CD10+. Three of these cases were also CD138+. Twelve bcl-6+ cases were bcl-2+, CD10-, six bcl-2-, CD10+, and two bcl-2-, CD10-. The three bcl-6- cases were bcl-2+, CD138- and two were CD10+. Bcl-2R was identified in 5/27 DLBCL with 4/5 bcl-2+, 3/4 tested CD10+ and 4/4 bcl-6+. Bcl-6R was identified in 7/26 including three with a classic FL phenotype. The vast majority of DLBCL in this study have an immunophenotype that supports a FCC origin. Although the proportion of DLBCL that co-expressed bcl-6, CD10 and bcl-2 was lower than for the FL, absence of bcl-2 or CD10 may be associated with higher grade FL It is also possible that bcl-6 expression is not completely specific for a FCC origin. Only a minority of cases suggested postfollicular differentiation. Only a minority of DLBCL show bcl-2R, suggesting that many have a different molecular pathogenesis than most low-grade FL. Bcl-6R did not exclude a FCC origin.     

Chromosomal translocation detected by bcl-1 and bcl-2 rearrangement in low-grade B-cell lymphomas in a European population

Twenty-nine cases of non-Hodgkin's lymphoma of low-grade malignancy in a European population were investigated for the presence of bcl-2 and bcl-1 gene rearrangement. The cases were classified according to the Kiel classification. It was shown that bcl-2 gene rearrangements were exclusively confined to centroblastic-centrocytic lymphomas. bcl-1 rearrangements were found in two cases of chronic lymphocytic leukaemia. As the chromosomal translocation t(14;18) is reported to occur in up to 85% of follicular lymphomas, our results provide additional evidence that the differentiation of low-grade B-cell lymphomas according to the Kiel classification defines biologically distinct entities.     

Significantly different bcl-2 expression profiles in gastric and non-gastric primary extranodal high-grade B-cell lymphomas

Fifty-five cases of primary extranodal high-grade B-cell non-Hodgkin's lymphoma were investigated for bcl-2 and p53 protein expression as well as for t(14;18) translocations and p53 mutations. Phenotypic and genotypic profiles were compared between tumours of gastric (27 cases) and non-gastric (28 cases) origin. bcl-2 protein expression was significantly lower in gastric (11/27) than in non-gastric (28/28) lymphomas (p<0.0001), while nuclear p53 protein expression did not differ significantly between these two groups. In the stomach, there were no significant differences in either bcl-2 or p53 expression profiles between high-grade lymphomas with (n=14) and without (n=13) evidence of a low-grade component of MALT type. However, secondary high-grade lymphomas showed a significant down-regulation of bcl-2 protein (p<0.0001) and, conversely, an up-regulation of p53 protein (p<0.0001) as compared with their low-grade tumour components. In extranodal high-grade B-cell lymphomas, bcl-2 protein expression was not associated with t(14;18) translocation. Only one gastric lymphoma had a p53 point mutation with potential alteration of the amino acid sequence. These findings indicate that primary gastric high-grade B-cell lymphomas are immunohistologically distinct from primary extranodal high-grade B-cell lymphomas of an origin other than in the stomach.     

Centroblastic and centroblastic/centrocytic lymphoma associated with a prominent epithelioid granulomatous response: a clinicopathologic study of 50 cases.

A minority of centroblastic and centroblastic/centrocytic cell lymphomas are accompanied by a prominent epithelioid cell response and were suggested to be a distinct variant of B-cell lymphoma of germinal center cell origin. To confirm the clinicopathologic significance of these mainly large B-cell lymphomas with an epithelioid cell response (LBCL-ER), we reviewed 50 patients with LBCL-ER and compared the results with those of 167 other diffuse large B-cell lymphomas (DLBCL) and 94 follicular lymphomas (FL) without epithelioid response. The patients with LBCL-ER showed a higher age distribution (median 71, P =.03), a female predominance (M:F = 18:32, P =.001) and less frequent involvement of extranodal sites >1 (P =.004) compared with those with DLBCL, and presented with a bulky mass of the affected lymph nodes in 54% of cases. They were also older (P =.0006) and more associated with the aggressive clinical factors such as serum LDH level and International Prognostic Index score than those with FL. Histologically, nine cases (18%) partially showed a follicular growth pattern, and the others (82%) were occupied by a diffuse growth pattern. The epithelioid cells were accumulated in large demarcated masses, partially imparting a lymphoepithelioid (Lennert) lymphoma-like appearance to some portions of the lesions in every case. Immunohistochemically, LBCR-ER was positive for CD20 in every case, CD10 in 43% of the cases, and BCL-2 in 56%. None of the tumor cells in the 40 cases tested expressed CD5 antigen. Immunostaining also often highlighted the remnants of the follicular dendritic cell network. The BCL-2 gene rearrangement was detected in only 19% of the cases examined. The survival curve of the cases of LBCL-ER was almost identical with that of DLBCL and was significantly inferior to that of FL. The centroblastic and centroblastic/centrocytic lymphoma with an epithelioid cell response may be regarded as the morphologic variant of DLBCL preferentially arising in the aged population and reflecting the disease progression of FL.     

CD43 expression in B cell lymphoma.

AIMS: To determine the expression of CD43 in frozen sections in a range of B cell lymphomas. METHODS: The monoclonal antibody WR14, clustered provisionally in the Fourth Leucocyte Typing Workshop as a CD43 reagent, was investigated by epitope blocking studies on formalin fixed reactive lymph node tissue, using the established CD43 antibody MT1, to validate its use as a CD43 reagent. CD43 expression was studied in 131 immunophenotypically defined B cell lymphomas, including lymphocytic lymphoma (Lc, n = 13), centrocytic lymphoma (Cc, n = 14), and a range of follicle centre cell lymphomas (FCC) including centroblastic/centrocytic follicular (CbCcF, n = 48), centroblastic diffuse (CbD, n = 39), centroblastic/centrocytic diffuse (CbCcD, n = 4), centroblastic follicular and diffuse (Cb FD, n = 3) and centroblastic/centrocytic follicular and diffuse (CbCc FD, n = 1). Nine lymphomas of mucosa associated lymphoid tissue (MALT) were also examined. RESULTS: Epitope blocking studies showed that WR14 is a CD43 reagent that binds to an epitope identical with or close to that recognised by MT1. Eleven of 13 (84%) cases of Lc and 11 of 14 (78%) cases of Cc expressed CD43; 87 of 95 (91%) cases of FCC did not. All eight low grade lymphomas of MALT were negative. One high grade lymphoma, transformed from a low grade MALT lymphoma, was positive for CD43. The expression of CD43 by tumours of B cell lineage was associated with the expression of CD5 (p < 0.001) although either antigen could occasionally be found in the absence of the other. CONCLUSION: CD43 reagents can be used in conjunction with CD5 antibodies for the immunophenotypic discrimination of follicle centre cell lymphomas from non-follicle centre cell lymphomas.     

An immunophenotypic and molecular study of primary large B-cell lymphoma of bone.

Primary non-Hodgkin's lymphomas of bone (PNHLB) is a rare form of extranodal lymphoma. Many studies have reported the clinical, radiologic, and histopathologic characteristics of PNHLB; however, their molecular features have not been well studied. In this report, we present the immunophenotypic and molecular characteristics of 20 primary large B-cell lymphoma (PLBCL) of bone from 20 adults. Most demonstrated centroblastic morphology, with the majority exhibiting nuclear multilobation. One case (5%) demonstrated anaplastic features with strong CD30 expression but was ALK-1 negative. BCL-6 expression was seen in 6 of 20 cases, and strong p53 protein expression was seen in 11 of 20 (55%) cases. The majority of cases analyzed (13/18 = 72%) demonstrated a clonal B-cell process by IgH gene rearrangement studies. Of the five cases that did not demonstrate a clonal population, two expressed BCL-6 protein. No cases demonstrated a bcl-2/JH rearrangement, but BCL-2 protein expression was seen in 11 of 20 (55%) cases. In summary, primary lymphoma of bone is largely a non-Hodgkin's lymphoma of large B-cell type. Our studies demonstrate that p53 and BCL-2 expression may play a role in the pathogenesis of PLCBL of bone. In addition, a subset of the cases are of putative germinal center B-cell origin based on the expression of BCL-6 protein and may be genetically distinct from follicle center lymphomas. The results provide evidence for molecular heterogeneity within primary large B-cell lymphomas of bone.     

bcl-10蛋白异常表达对黏膜相关淋巴组织结外边缘区B细胞淋巴瘤的诊断价值

目的探讨bcl-10蛋白表达对黏膜相关淋巴组织结外边缘区B细胞淋巴瘤（MALT淋巴瘤）的诊断价值。方法收集140例不同部位的MALT淋巴瘤,包括胃38例、眼眶35例、肠16例、皮肤15例、涎腺15例、肺14例、甲状腺3例、其他部位4例。对照：10例扁桃体反应性滤泡增生（RFH）、5例眼眶的淋巴组织增生和143例非MALT淋巴瘤、不同类型的非霍奇金淋巴瘤（NHL）,包括20例NK／T细胞淋巴瘤、20例滤泡性淋巴瘤（FL）、20例间变性大细胞淋巴瘤（ALCL）、20例淋巴结内弥漫大B细胞淋巴瘤（DLBCL）、10例原发胃DLBCL、13例淋巴结边缘区淋巴瘤（NMZL）、12例套细胞淋巴瘤（MCL）、11例脾脏边缘区淋巴瘤（SMZL）、6例血管免疫母细胞性T细胞淋巴瘤（AITL）、6例外周T细胞淋巴瘤（PTCL）、3例B．小淋巴细胞淋巴瘤（B-SLL）、1例淋巴浆细胞性淋巴瘤（LPL）和1例浆细胞瘤。免疫组织化学EnVision法检测bcl-10蛋白;免疫组织化学双标记法检测CD20与bcl-10的共表达。结果在扁桃体RFH中,bel-10蛋白呈中等强度表达于生发中心B细胞质中,套细胞不表达,边缘区细胞和副皮质区T细胞呈弱表达。在眼眶淋巴组织增生中,2例bel-10阴性,3例主要呈淋巴滤泡生发中心B细胞质阳性,与扁桃体RFH的表达类似。在非MALT淋巴瘤的其他类型NHL中,除3例（3／10）原发胃DLBCL呈胞核阳性外,其余均未见胞核表达;在不同NHL中的胞质阳性分别为：结内（12／20）和胃（7／10）DLBCL、FL和ALCL（16／20）、PTCL（5／6）、AILT（6／6）、NMZL（13／13）、SMZL（11／11）、B-SLL（3／3）和浆细胞瘤（1／1）,11例MCL呈胞质可疑阳性,20例NK／T细胞淋巴瘤和1例LPL阴性;在部分淋巴瘤中可见肿瘤性细胞表达而反应性小淋巴细胞不表达：MALT淋巴瘤之bcl-10的总表达率为92．1％（129／140）,其中54．3％（76／140）胞质阳性,37．9％（53／140）胞核阳性;但不同部位之胞核阳性率有所不同。在MALT淋巴瘤中,bcl-10蛋白核强表达最常见于眼眶（25．7％,9／35）;除出现异常bcl-10胞核表达外,约20％有反应性滤泡的病例呈生发中心失表达。双标记显示bcl-10阳性细胞为CD20阳性细胞,但CD20阳性细胞多于bcl-10阳性细胞。结论（1）淋巴细胞增生性病变中bcl-10蛋白普遍表达,细胞质表达可出现在多数NHL和反应性增生中,但在淋巴瘤中呈肿瘤细胞表达而反应性细胞不表达,提示bcl-10异常可能与部分淋巴瘤的形成有关;（2）细胞核内bcl-10异常表达主要见于MALT淋巴瘤;眼眶、肺等部位的胞核强阳性和生发中心阴性的特殊模式,对MALT淋巴瘤的诊断及其与反应性病变的鉴别诊断有一定辅助意义。     

Follicular origin of a subset of CD5+ diffuse large B-cell lymphomas

Most follicular lymphomas (FLs) have a phenotype consistent with the origin from CD5-, CD10+, bcl-6+ follicular center cells and can progress to diffuse large B-cell lymphoma (DLBCL). CD5 is expressed in about 10% of DLBCLs, showing prognostic value, whereas expression is rare in FL. We present 6 cases with coexisting features of CD5+ FL and CD5+ DLBCL, supporting a follicular origin for some CD5+ DLBCLs. The follicular areas showed a meshwork of CD21+ follicular dendritic cells that were lacking in the DLBCL areas. All cases showed a clonal CD19+, CD20+, CD5+, and CD10+ population in both follicular and diffuse areas. Molecularly, 4 of 6 cases demonstrated immunoglobulin heavy chain rearrangements and 1 case, a bcl-2/immunoglobulin heavy chain gene rearrangement. Somatic hypermutations were high in all 4 cases, in keeping with their germinal center origin. Four of five patients died of disease within 42 months, consistent with the proposed prognostic value of CD5 expression in DLBCL. Our data describe an aggressive variant of CD5+ FL suggesting the follicular origin of some CD5+ DLBCLs.