结节性淋巴细胞为主型霍奇金淋巴瘤与经典型霍奇金淋巴瘤中p63表达及临床意义

目的探讨p63在结节性淋巴细胞为主型霍奇金淋巴瘤(nodular lymphocyte predominant Hodgkin lymphoma,NLPHL)和经典型霍奇金淋巴瘤(classical Hodgkin lymphoma,CHL)中表达及临床意义。方法采用免疫组化Eli Vision法检测15例NLPHL和54例CHL中CD45、CD30、p63、PAX5、CD20、CD15、Oct-2、BOB1、MUM1、EMA、EBV-LMP1、Ki-67等表达,用原位杂交法检测12例CHL中EBER表达。结果 NLPHL中p63阳性率(53.3%,8/15)明显高于CHL组(0,0/54)(P<0.05)。结论p63蛋白表达常见于NLPHL,有助于NLPHL和CHL的鉴别诊断。     

B细胞特异性激活蛋白Pax-5在淋巴瘤组织中的表达

目的探讨B细胞特异性激活蛋白(BSAP)／Pax-5在淋巴瘤的表达情况及应用价值。方法按2001年WHO关于淋巴造血组织肿瘤分类标准收集102例弥漫性大B细胞淋巴瘤(DLBCL)、3例滤泡型淋巴瘤(FL)、3例黏膜相关淋巴组织结外边缘区B细胞淋巴瘤(MALT淋巴瘤)、1例结节性淋巴细胞为主型的霍奇金淋巴瘤(NLPHL)、10例间变性大细胞淋巴瘤(ALCL)和10例浆细胞瘤,用免疫组织化学LSAB法同步检测比较BSAP与CD20的表达情况。结果102例DLBCL全部表达CD20,100例表达BSAP,3例FL、3例MALT淋巴瘤和1例NLPHL BSAP和CD20全部阳性表达,10例ALCL、10例浆细胞瘤BSAP和CD20全部阴性表达。BSAP与CD20的表达差异无统计学意义。结论。BSAP/Pax-5是一种新的B细胞标记,阳性信号定位于细胞核,抗BSAP抗体在常规外科病理诊断工作中的应用价值有限。     

肺原发性淋巴瘤样肉芽肿型大B细胞淋巴瘤临床病理特点

目的探讨肺原发性淋巴瘤样肉芽肿（lymphomatoid granulomatosis,LG）型大B细胞淋巴瘤的临床病理特点、诊断与鉴别。方法分析1例肺LG的临床病理特点,行SP法免疫组化检测和原位杂交（EBER）,并复习文献。结果患者女性,54岁,临床上表现为双肺快速增多、增大的境界清楚的圆形结节,呈孤立性或弥漫性分布,并出现发热、体重减轻、全身无力等症状。胸腔镜肺活检组织示弥漫淋巴细胞及散在异形性大细胞浸润,并见血管受累和坏死,免疫表型：大细胞CD45＋,CD20＋＋,CD30＋,EBV＋,EBER＋,CD68＋;CD15、ALK、EMA、CD3、CD56等均-（散在小淋巴细胞CD3＋）。结论LG是一种罕见的原发于肺的淋巴瘤样肉芽肿型大B细胞性淋巴瘤,与EBV感染有关。诊断困难,临床上需要与Wegener肉芽肿、结核、结节病等肺结节性病变鉴别。病理学上也需与结核、非特异性肉芽肿病、霍奇金淋巴瘤及非霍奇金淋巴瘤等鉴别。经形态学、免疫表型与临床、影像学相结合可明确诊断。     

儿童腹腔非霍奇金B细胞淋巴瘤的临床病理及免疫表型分析

目的 探讨儿童腹腔原发性非霍奇金B细胞淋巴瘤的临床病理、免疫表型与EBER特征及其病理诊断和鉴别诊断.方法 按WHO(2008年)淋巴瘤分类标准分析74例儿童腹腔原发性非霍奇金B细胞淋巴瘤的临床病理资料,制备组织芯片,进行免疫组织化学SP法染色,EBER原位杂交和c-myc基因荧光原位杂交,观察CD20、CD79a、CD3、CD10、bcl-6、MUM1、bcl-2、CD43、CD38和Ki-67蛋白的表达和EBER表达特征,并区分伯基特淋巴瘤(BL)、弥漫性大B细胞淋巴瘤(DLBCL)和介于BL和DLBCL之间的不能分类的B细胞淋巴瘤(DLBCL/BL)病理类型,在DLBCL中再区分其生发中心B细胞型(GCB)和非生发中心B细胞型(non-GCB)的分化特征.结果 儿童腹腔非霍奇金B细胞淋巴瘤中BL为65例(87.8%),DLBCL为4例(5.4%),DLBCL/BL为5例(6.8%).临床以腹痛、腹部包块、肠梗阻及肠套叠为主要发病症状.BL免疫组织化学表达CD20(65例)、CD79a(65例)、CD10(63例)、bcl-6(62例)、MUM1(15例)、CD43(46例)和CD38(63例);不表达CD3、bcl-2;27例(41.6%)EBER阳性;54例(93.0%)c-myc基因位点断裂.DLBCL免疫组织化学表达CD20(4例)、CD79a(4例)、CD10(3例)、bcl-6(2例)、MUM1(2例)、bcl-2(3例)、CD43(2例)、CD38(2例);不表达CD3;其中2例GCB,2例non-GCB;EBER阴性;1例c-myc基因位点断裂.DLBCL/BL免疫组织化学表达CD20(5例)、CD79a(5例)、CD10(5例)、bcl-6(4例)、MUM1(3例)、CD43(5例)、CD38(3例),不表达CD3和bcl-2;4例EBER阴性;3例c-myc基因位点断裂.结论 儿童腹腔非霍奇金B细胞淋巴瘤具有侵袭性生长的特点,以BL为主要病理类型.临床以腹痛、腹部包块、肠梗阻及肠套叠为主要发病症状,主要累及回盲部肠组织及周围系膜淋巴结,病理形态、免疫表型、EBER、c-myc基因的检测对BL、DLBC及DLBCL/BL淋巴瘤的诊断和鉴别诊断有重要作用.     

结节性淋巴细胞为主型霍奇金淋巴瘤的诊断与鉴别诊断

目的　探讨结节性淋巴细胞为主型霍奇金淋巴瘤 (NLPHL)的诊断和鉴别诊断特点。方法　对 1980～ 2 0 0 0年 2 4 5例霍奇金淋巴瘤 (HL)进行回顾性分析 ,发现NLPHL4例 ;另外 2例NLPHL为 2 0 0 0年会诊病例 ;复旦大学肿瘤医院提供 1例。 7例均应用链霉菌抗生物素蛋白 过氧化物酶法(SP法 )检测瘤细胞 (CD4 5、CD2 0、CD15、CD30、波形蛋白 )和背景细胞 (CD3、CD2 0、CD4 5RO、CD5 7、CD6 8、TIA 1)的免疫表型 ,并采用WHO1997年淋巴瘤诊断标准重新分类。结果　NLPHL7例 ,男 4例 ,女 3例 ,平均年龄 4 3.8岁 ,中位年龄 4 3岁 ,表现为颈部、锁骨上或腋窝淋巴结肿大 ,临床Ⅰ期。组织学上 ,NLPHL病变淋巴结结构破坏 ,大部分为肿瘤性病变 ,主要呈结节性生长 ,结节内可见L&H细胞浸润 ,其中 1例NLPHL病变淋巴结可见少部分呈生发中心进行性转化 (PTGCs)改变。免疫组织化学染色显示瘤细胞呈CD4 5、CD2 0阳性 ,CD15、CD30、波形蛋白阴性 ,背景细胞中可见大量CD2 0阳性的B小淋巴细胞及较多CD5 7阳性细胞 ,TIA 1阳性细胞极少见。结论　对NLPHL的诊断必需结合免疫表型特征 ,要注意与经典型霍奇金淋巴瘤及B细胞淋巴瘤相鉴别     

经典型霍奇金淋巴瘤中CXCR5的表达及临床病理意义

目的 探讨经典型霍奇金淋巴瘤(classic Hodgkin lymphoma, CHL)中CXCR5的表达及意义。方法 采用免疫组化EnVision两步法检测33例CHL中CXCR5的表达,分析CXCR5在CHL四种亚型中的表达情况及临床病理诊断意义;同时收集10例ALK阳性间变性大细胞淋巴瘤(anaplastic large cell lymphoma, ALCL)和10例ALK阴性ALCL作为对照组,对比分析CXCR5的表达情况。结果 33例CHL中,31例CXCR5阳性(93.94%):其中结节硬化型15例(15/16,93.75%)、混合细胞型12例(12/13,92.31%)、淋巴细胞丰富型2例,淋巴细胞消减型2例。CHL中CXCR5的表达情况分别为：33例CD30阳性和PAX5弱阳性中31例阳性(93.94%);14例CD15阴性中12例阳性(85.71%);26例CD20阴性中24例阳性(92.31%);6例LMP1阴性中5例阳性;11例EBER阴性中10例阳性(90.91%)。对照组20例ALCL中,肿瘤细胞CXCR5均阴性。结论 CHL中CXCR5阳性率较高,当肿瘤...     

骨髓活检组织淋巴瘤的病理诊断和分型

目的 探讨组织形态改变、免疫组织化学、基因重排在淋巴瘤骨髓侵犯的病理诊断和分型中的作用。材料与方法 对62例甲醛固定、石蜡包埋的骨髓活检组织,分别做了组织学、EnVision法观察和免疫球蛋白重链(IgH)基因和TCRγ基因重排检测。结果 慢性淋巴细胞性白血病／小淋巴细胞淋巴瘤(CLL／SLL)的异型淋巴细胞呈小梁间结节状或散在分布,有时可见假滤泡结构。滤泡型淋巴瘤(FCL)表现为结节性小梁旁或小梁间的浸润,结节内小淋巴样细胞松散聚集。淋巴浆细胞性淋巴瘤(LPL)主要为小梁间弥散浸润,在小而圆的淋巴细胞间可见散在数量不等的浆细胞样淋巴细胞。边缘区淋巴瘤(MZL)则见模糊的或界限不清的小梁间或小梁旁结节,一些细胞胞质透明。套细胞性淋巴瘤(MCL)异型细胞小到中等大小,缺乏副免疫母细胞和假滤泡。毛细胞性淋巴瘤(HCL)瘤细胞胞膜多清晰,胞质丰富透明,常形成荷包蛋样表现。霍奇金病可见大核瘤细胞,核仁明显。T-非霍奇金淋巴瘤(NHL)浸润骨髓主要为小梁间间质性散在或弥漫分布,胞质多透明,核有芋艿样或脑回状改变,DLBL造血细胞间体积大的瘤细胞散在或弥漫分布。CD3对T细胞来源、CD20和CD79对B细胞来源淋巴瘤有鉴别诊断价值,cyclin D1和(SD5阳性对MCL具有诊断性价值,bcl-2和CD10阳性则对FCL具有诊断性意义,而CLL／SLL除了(SD20和CD79阳性外,也可CD5和CD23阳性。HCL的瘤细胞CD25强阳性。CD15、CD30和Fascin也适用于骨髓霍奇金病的诊断。骨髓中CLL／SLL,LPL,MZL及DLBL的IgH重排率(80％、60％、66．7％、70％)及T—NHL的TCRγ重排率(66．7％)较高。结论 综合组织形态改变、免疫组织化学和IgH／TCRγ重排检测,有助于淋巴瘤骨髓侵犯的诊断和分型,有助于发现骨髓中为数不多的淋巴瘤细胞。     

富于T细胞/组织细胞的B细胞淋巴瘤的诊断

目的：探讨富于T细胞／组织细胞B细胞淋巴瘤（TCRBCL）的诊断。方法：用S－P石蜡免疫组化法检测22例依据形态学诊断的霍奇金淋巴瘤细胞和背景细胞的免疫表型。结果：4／22例是TCRBCL,3例富于T小淋巴细胞,1例富含组织细胞;瘤细胞3例呈中心母细胞样和免疫母细胞样。1例呈腔隙型细胞样,弥漫散在分布。免疫组化瘤细胞呈CD20（＋）、CD15（－）、CD30（－）、CD21（－）、vimentin(-)。背景细胞CD45RO（＋）／CD68（＋）细胞占绝对优势,为浸润细胞的70％－90％;CD20（＋）细胞散在,CD57（＋）稀少。16例为经典型霍奇金淋巴瘤（CHL）,瘤细胞为CD15（＋）（75％）、CD30（＋）（100％）、vimentin( )(19%)、CD21（－）、CD20（－）及CD45（－）,背景细胞CD45RO（＋）和CD20（＋）数量基本相等,CD57（＋）较少。1例为结节性淋巴细胞为主型霍奇金淋巴瘤（NLPHL）,瘤细胞呈CD20（＋）、CD45（＋）、CD30（－）、CD15（－）,而背景细胞中CD57（＋）较多。结论：石蜡免疫组化在TCRBCL诊断中起重要作用,而且也应用于CHL、NLPHL及TCRBCL间鉴别诊断。     

混合性经典型霍奇金淋巴瘤合并T细胞淋巴瘤一例

混合性淋巴瘤是指两种不同类型的淋巴瘤同时发生。该例患者男性,44岁,因无意中发现左颈部肿物入院,彩超提示左颈部4 cm大小肿物。镜下见弥漫小淋巴细胞间散在核大异型细胞。免疫组织化学显示散在核大细胞CD15、CD30、MUM1、PAX5等标记阳性,EB病毒编码的小RNA(EBER)显色原位杂交(CISH)检测显示核大细胞阳性,符合经典型霍奇金淋巴瘤。免疫组织化学显示背景小淋巴细胞CD3、CD2、CD7等标志物阳性,EBER CISH检测显示部分细胞阳性,T细胞受体基因检测提示2个位点单克隆重排,符合T细胞淋巴瘤。混合性淋巴瘤治疗不同于普通的淋巴瘤,需要综合制定化疗方案。     

原发性骨非霍奇金淋巴瘤23例临床病理分析

目的探讨原发性骨非霍奇金淋巴瘤的临床病理特点、临床预后指标及Pax-5蛋白表达的诊断价值。方法复习23例骨非霍奇金淋巴瘤患者的临床资料,对血清LDH、国际预后指数及治疗与预后的关系进行分析。并用EnVision两步法标记Pax-5,比较BSAP与CD20及CD79α的表达情况。结果23骨非霍奇金淋巴瘤均为B细胞淋巴瘤,其中22例患者的5年生存率为65．9％,血清LDH升高、国际预后指数高危类对预后不利（两者P值分别为0.02和0.01）。23例中有22例表达Pax-5,Pax-5与CD20及CD79α的表达差异无统计学意义。结论骨非霍奇金淋巴瘤以B细胞淋巴瘤多见,预后较好,血清LDH和国际预后指数是判断预后的指标。Pax-5可应用于原发性骨非霍奇金淋巴瘤的诊断。     

Composite marginal zone B-cell lymphoma and classical Hodgkin's lymphoma: a clinicopathological study of 12 cases

AIMS: Classical Hodgkin's lymphoma (cHL) rarely coexists as composite lymphoma with B-cell non-Hodgkin's lymphoma (B-NHL). We characterized 12 cases of composite marginal zone B-cell lymphoma (MZBL) and cHL by immunohistochemistry and molecular biology. METHODS AND RESULTS: Eight patients had gastric MZBL of mucosa-associated lymphoid tissue (MALT)-type, in five cases with a diffuse large B-cell lymphoma component. Concurrent cHL was observed either in the stomach wall, regional, or distant lymph nodes. One patient each had composite pulmonary/thyroid MZBL of MALT-type and cHL. In two cases, nodal composite MZBL and cHL was observed. cHL displayed features of mixed cellularity type in 10 cases, while in two cases only scattered Hodgkin- and Reed-Sternberg (H/RS) cells were noted. H/RS cells expressed CD30, multiple myeloma oncogene 1 protein (MUM1P), p53 (100%), CD15 (58%), CD20 (58%) and Epstein-Barr virus-associated LMP1 (50%). No t(11;18)(q21;q21) was detected in composite MZBL of MALT-type and cHL. CONCLUSIONS: MZBL and cHL may occur as composite lymphoma, possibly reflecting clonal lymphoma progression. Derivation from extranodal MZBL of MALT-type should be excluded in cases in which a diagnosis of primary extranodal cHL is considered.     

Morphological variability of tumour cells in T-cell-rich B-cell lymphoma

T-cell-rich B-cell lymphoma (TCRBCL) is an unusual lymphoma which is difficult to diagnose. A majority of reactive T-cells and numerous histiocytes mask the few large neoplastic B-cells. Fourteen cases of TCRBCL were studied in order to identify the main histological and cytological features useful for this diagnosis. Neoplastic cells are atypical and sometimes difficult to classify. Several types are seen; they are mostly centroblasts, which represent more than 50% of the tumour cells but are sometimes multilobated, immunoblasts- or Reed-Sternberg-like cells. Interestingly, at least two, and often three, types of tumour cell are present in all the cases. Epithelioid cells and histiocytes are always found and are often numerous. Hypervascularization and fibrosis are present in the majority of cases, but without annular bands. Necrosis is absent. All tumour cells express CD20 but EMA is expressed in less than half the cases. In two cases, the association of a diffuse large B-cell lymphoma in one site and a TCRBCL in another suggests that TCRBCL may be considered as a peculiar pattern of a diffuse large B-cell lymphoma with a strong stroma reaction. TCRBCL may not represent a clinicopathological entity.     

Cytodiagnosis of non-Hodgkin's lymphoma

Summary A cytomorphological analysis using a large number of variables was applied to 136 fine needle aspirations and 122 imprints from 258 biopsy proven lymphoid lesions, including 203 non-Hodgkin's lymphomas (NHL), 12 true histiocytic neoplasms and 43 lymphoid hyperplasias. Characteristics of the various cell types are described using the Kiel classification predominantly.Two blindly performed consecutive cytological analyses, indicated as Cyt I and Cyt II respectively, were compared with histology. False-positive conclusions did not occur. False-negative conclusions were present in 3.7% of cases. The intra-observer reproducibility between Cyt I and Cyt II was 93%.The inter-observer reproducibility between the 4 authors was examined in 50 cases; consensus regarding malignancy, exact NHL type and benign cytology was 88%, 70% and 100% respectively. Cytodiagnosis of NHL is a reliable method with a high sensitivity which can add substantial information to tissue diagnosis in troublesome cases.Fine needle aspirations, if adequately performed, had the same cellularity, quality and cellular composition as imprints. Aspiration cytology is very useful for the selection of a representative lymph node for surgical biopsy, for the diagnosis of recurrent NHL, for staging the extent of disease, for the diagnosis of cases in which tissue biopsy is not possible, and as a variable for monitoring treatment.Abbreviations Cyt I first blind cytological screening - Cyt II second blind cytological screening - FNA fine needle aspiration - l.g.b. lymphoglandular body - LH lymphoid hyperplasia - MHT malignant histiocytic tumour - NHL non-Hodgkin's lymphoma An editorial will follow giving comment on the fundamental question of the value of aspiration cytology in lymph node pathology.     

Nodular sclerosing Hodgkin's disease and large cell lymphoma. Immunophenotypic characterization of a composite case

Summary Composite lymphomas have rarely been reported in Hodgkin's disease (HD), except in the lymphocyte predominance sub-type, and immunohistochemical investigations have been performed in only few cases. We describe the histological and immunophenotypical findings in a case of composite nodular sclerosing HD and high-grade, large cell non-Hodgkin's lymphoma (NHL). In our case HD and NHL cells displayed striking morphological and immunophenotypical divergence, suggesting a lack of correlation between the two neoplasms.     

Follow-up of sperm concentration and motility in patients with lymphoma

Lymphomas are a group of diseases, prevalent at reproductive age. Fertility is notoriously reduced among lymphoma patients. This study evaluates pre- and post-treatment semen concentration and motility, and factors associated with semen quality deterioration. We followed-up 33 patients with non-Hodgkin's lymphoma or with Hodgkin's disease during the years 1987-1997 who were referred for semen cryopreservation. Pretreatment semen analysis, and hormonal profile were recorded at diagnosis and at least 1 year after completion of the treatment, and compared. Medical records for disease type, disease stage and treatment protocols were related to long-term sperm outcome. Hormonal concentrations were not predictive of post-treatment sperm concentration. In patients with localized disease, initial sperm concentration and motility tended to be preserved, compared with patients with widespread disease (P: = 0. 016). In Hodgkin's disease patients, treatment with the adriamycin, bleomycin, vinblastine and dacarbazine (ABVD) protocol was superior to the mechloretamine, vincristine, procarbazine and prednisone with ABV protocol regarding germinal toxicity (P: = 0.0008). The post-treatment sperm outcome was better in patients treated with local irradiation than in those who did not undergo irradiation (P: = 0.0027). No predictive tools for post-treatment fertility were found and, therefore, every patient with a lymphoma should have his semen cryopreserved at diagnosis.     

A proposal for classification of lymphoid neoplasms (by the International Lymphoma Study Group)

A new classification of lymphoid neoplasms, mostly based on existing terminology, is proposed by the International Lymphoma Study Group. The proposed classification was reached through a consensus of the members, despite their diverse backgrounds, and consists of a listing of currently recognized clinicopathological entities. These tumours are divided into three major categories: B-cell neoplasms, T-cell and postulated natural killer cell neoplasms, and Hodgkin's disease. The characterization of each entity is based on a synthesis of all available information. This concept departs from a purely morphological approach to lymphoma classification, which is considered to be inadequate, because many biologically distinctive lymphoma types can exhibit a broad and overlapping morphological spectrum. Some entities are provisional, pending further data to confirm that their recognition is reproducible. The salient clinicopathological features of each entity are summarized in this review.     

Lymphomas of the Mediastinum

The purpose of this clinicopathologic overview is to describe the types of lymphomas that present in the mediastinum. A comparison of the frequency of the different subtypes of lymphoma that are found in children and adults is provided. In general, immunohistochemistry and immunophenotyping studies are essential to the laboratory workup of neoplasms presenting in the mediastinum. An assessment of proliferative index in lymphoma is most helpful to determine tumor aggressiveness and patient prognosis. Electron microscopy is most helpful in the differential diagnosis of mediastinal neoplasms, where lymphomas may be distinguished from nonlymphomatous neoplasms using key ultrastructural features. The role of electron microscopy in the subclassification of lymphomas is mostly academic, with a few exceptions. The varied ultrastructural appearance of Hodgkin's cells and of different subtypes of non-Hodgkin's lymphoma is illustrated, using cases from our patient files. An ultrastructural study of lacunar cells in Hodgkin's disease provides evidence that the formation of lacunae may have a structural and/or physiologic basis. Mummified cells showing some of the features of a physiologic form of cell death, called apoptosis, are also described.     

Changes in Clinico-pathological Features of Hodgkin's Disease and Follicular Lymphoma in Nagoya, Japan, over a 21-year Period (1965-85)

To study changes in the clinico-pathological features of malignant lymphomas in Japan, the histopathological and clinical features of 71 cases of Hodgkin's disease and 49 cases of nodal follicular lymphoma occurring in Nagoya were compared in three different periods (1965 71,1972 78 and 1979-85). The proportional frequency of Hodgkin's disease among total lymphomas (10%) and that of follicular lymphoma among non Hodgkin's nodal lymphomas (18%) did not vary over the study period. As to the histological patterns of Hodgkin's disease, the relative frequency of the nodular sclerosis (NS) type, which is relatively common in young women, increased, but that of other types decreased in the more recent periods. For follicular lymphoma, the relative frequency of the completely follicular type, which is more common in the United States than in Japan, increased. The five-year survival rate in patients with follicular lymphoma improved more recently even after adjusting for the effects of other prognostic factors. This recent increase in survival rates may be due partly to the recent improvement in cancer treatment, but is also related to the recent increase in patients with better prognostic features, i.e. the NS type of Hodgkin's disease. These variations over time suggest that the patterns of malignant lymphomas in Japan might be gradually changing, probably because of westernization, as seen in cancers of other organs. Acta Pathol Jpn 40: 713 721, 1990.     

Composite lymphoma: the interface between Hodgkin's and non-Hodgkin's lymphoma

Hodgkin's lymphoma is a rare neoplasm mainly affecting young people. Within the last decade, nodular lymphocyte-predominant Hodgkin's lymphoma (NLPHL) has been separated from all other cases of the so-called classical type. Moreover, the derivation of Hodgkin's lymphoma from germinal centre B-cells has been established, giving rise to a possible clonal relationship between Hodgkin's lymphoma and the non-Hodgkin's lymphomas (NHLs). The interface between them therefore has both diagnostic and biological aspects. Diagnostic difficulties arise, due to overlapping definitions, between biologically unrelated entities, e.g. classical Hodgkin's lymphoma and NLPHL or anaplastic large cell lymphoma, respectively. On the other hand, there is a biological grey zone regarding composite lymphomas consisting of Hodgkin's lymphoma and any NHL. This simultaneous or subsequent occurrence of Hodgkin's lymphoma and non-Hodgkin's lymphomas may, or may not, be clonally related. For management purposes lymphomas, e.g. NLPHL and T cell-rich B-cell lymphoma, must be distinguished along a continuous spectrum of progression.     

Rare expression of KIT (CD117) in lymphomas: a tissue microarray study of 1166 cases

AIMS: Imatinib mesylate specifically inhibits KIT tyrosine kinase activity, and has been proven to be effective in the treatment of gastrointestinal stromal tumours. Because other KIT-expressing malignancies might benefit from Imatinib therapy, we evaluated the distribution and expression of KIT in 1166 cases of malignant lymphoma. MATERIALS AND RESULTS: Tissue microarrays (TMAs) containing 824 non-Hodgkin's lymphoma (NHL) and 342 Hodgkin's lymphoma (HL) cases were immunohistochemically analysed for the expression of the KIT protein. Two KIT-positive NHLs were sequenced using polymerase chain reaction analysis. One T-cell lymphoma and one follicular lymphoma of the 747 NHL cases (0.3%) were positive for KIT. All HLs were Kit-negative. None of the KIT-positive cases showed a kit gene mutation. CONCLUSIONS: KIT expression is a very rare event in NHL and virtually absent in HL. In the few positive cases, the aberrant expression is not caused by a mutation in the 'hot-spots' of the kit gene, indicating that treatment of these tumours with Imatinib may be ineffective.