T淋巴母细胞淋巴瘤/白血病的临床病理研究

目的 分析和总结T淋巴母细胞淋巴瘤/白血病(T-LBL/ALL)的临床、组织学、免疫表型特征,以提高对T-LBL/ALL的认识和诊断水平.方法 采用HE、免疫组织化学(EliVision法)、原位杂交及聚合酶链反应等方法结合临床资料对128例T-LBL/ALL进行了分析.结果 男94例,女34例.男女比2.8:1.年龄4-88岁,平均27岁,中位年龄22岁.58例病变累及淋巴结,27例累及淋巴结外,43例淋巴结内外均有累及.其中73.3%(74/101)累及颈部淋巴结,42.6%(43/101)累及纵隔.病变以弥漫为主,少数呈结节状.多数病例的瘤细胞为中小细胞,少数瘤细胞较大.瘤细胞表达末端脱氧核苷酸转移酶(TdT,94.5%,121/128)、CD34(49.0%,48/98)、CD3(72.2%,78/108)、CD7(96.3%,104/108)、CD43(88.9%,56/63)、CD79a(7.1%,5/70)、CD10(32.9%,25/76)、CD99(96.7%,58/60)、Pax-5(4.4%,4/91);128例髓过氧化物酶(MPO)均为阴性.共随访51例(39.8%),随访时间1～53个月.总体存活率68.6%;总体中位生存时间12个月.不同年龄组中CD3阳性率差异有统计学意义,30岁以上的病例CD3阳性率显著降低.CD10阳性患者的生存时间较阴性患者的生存时间短.5例T细胞受体(TCR)基因重排检测结果显示,4例有TCR基因克隆性重排.结论 T-LBL/ALL主要发生于青少年,以颈部淋巴结肿大和(或)纵隔肿物为主要临床表现.多数病例的肿瘤细胞以中小细胞为主,弥漫分布,但是也应注意到少数病例细胞较大,或结节状生长.免疫组织化学CD7、Pax-5、TdT、CD34、Ki-67五项抗体的联合应用有助于大多数病例确诊.对极少数病例可辅以TCR基因重排检测.     

淋巴样增强结合因子1蛋白表达在淋巴母细胞淋巴瘤/急性淋巴细胞白血病中的诊断及鉴别诊断研究

目的研究淋巴样增强结合因子1(LEF1)蛋白在淋巴母细胞淋巴瘤/急性淋巴细胞白血病(LBL/ALL)和小B细胞淋巴瘤中的表达,探讨其在LBL/ALL病理诊断及鉴别诊断中的价值。方法收集2012年1月至2019年12月上海市同济医院就诊及会诊的53例LBL/ALL石蜡组织标本,采用免疫组织化学法检测LEF1、末端脱氧核苷酸转移酶(TdT)蛋白表达,比较LEF1和TdT诊断的特异度、灵敏度。检测小B细胞淋巴瘤包括慢性淋巴细胞白血病/小淋巴细胞淋巴瘤(CLL/SLL)、滤泡性淋巴瘤、套细胞淋巴瘤、边缘区B细胞淋巴瘤、华氏巨球蛋白血症/淋巴浆细胞淋巴瘤共77例LEF1蛋白表达,比较LBL/ALL与各亚型小B细胞淋巴瘤LEF1蛋白表达差异。单因素分析LEF1蛋白表达与LBL/ALL患者总生存与无进展生存的相关性。结果LBL/ALL中LEF1蛋白表达阳性率为100%(53/53),中位值90%;TdT阳性率为84.9%(45/53;T-LBL/ALL为78.1%,B-LBL/ALL为95.2%),中位值80%;LEF1和TdT阳性率及中位值差异均有统计学意义(P值分别为0.008,0.001)。CLL/SLL LEF1蛋白表达阳性比例为14/18,中位值45%;滤泡性淋巴瘤(0/16)、套细胞淋巴瘤(0/16)、边缘区B细胞淋巴瘤(0/19)、华氏巨球蛋白血症/淋巴浆细胞淋巴瘤(0/8)LEF1蛋白均为阴性。B-LBL/ALL与小B细胞淋巴瘤比较,LEF1阳性率有显著差异。本组LBL/ALL病例中位随访时间16个月,LEF1蛋白表达与LBL/ALL总生存和无进展生存差异无统计学意义。结论LEF1免疫组织化学检测诊断LBL/ALL有很高的灵敏度和较好的特异度,与TdT联用可提高LBL/ALL诊断率。     

T淋巴母细胞性淋巴瘤/髓系肉瘤合并朗格汉斯细胞组织细胞增生症的临床病理分析

目的探讨T淋巴母细胞性淋巴瘤(T-LBL)/髓系肉瘤(MS)合并朗格汉斯细胞组织细胞增生症(LCH)的临床病理学特征、免疫表型及预后。方法收集中山大学附属佛山医院和首都医科大学北京友谊医院2013年12月至2019年4月间6例T-LBL/MS合并LCH患者临床及病理资料,采用HE染色、免疫组织化学EnVision法、原位杂交法进行染色分析,检索文献并复习。结果6例患者中,男性2例,女性4例。4例为T-LBL合并LCH,1例为T-LBL/MS合并LCH,1例为MS合并LCH。患者年龄5~77岁,中位年龄59岁。3例为多发淋巴结内病变,另3例为多发淋巴结及皮肤/肝脾病变。5例显示淋巴结结构破坏,3例可见数个残留萎缩的滤泡。瘤细胞有2种形态,一种为体积中等大小的淋巴样细胞,呈片巢状分布。核圆形、卵圆形,这类细胞主要分布于残留的滤泡旁和副皮质区。另一种为组织细胞样细胞,体积大,胞质丰富淡染或嗜双色性。核卵圆形、不规则形,呈折叠状,主要分布于淋巴结边缘窦、髓窦和滤泡间区。所有病例的背景嗜酸性粒细胞浸润不明显。中等大小淋巴样细胞表现为末端脱氧核苷酸转移酶(TdT)、CD99、CD7阳性,不同程度表达CD34、髓过氧化物酶(MPO)、CD2、CD3,Ki-67阳性指数多在30%~50%之间。而组织细胞样细胞表现为CD1a阳性、S-100蛋白阳性、Langerin表达不一,不同程度表达CD163/CD68,不表达T和B细胞标志物,Ki-67阳性指数多在10%~20%之间。所有病例均无EB病毒感染。随访4例(随访时间6~63个月,中位时间18.5个月),其中1例死亡,3例带病生存。结论T-LBL/MS合并LCH是一种少见的混合型幼稚淋巴造血系统疾病,多发生于皮肤、淋巴结,临床进展凶猛,预后差,故充分认识同一组织内两种病变成分有助于精准诊断与治疗。     

浆膜腔积液淋巴母细胞淋巴瘤/急性淋巴细胞白血病的细胞学诊断分析

目的探讨浆膜腔积液淋巴母细胞淋巴瘤/急性淋巴细胞白血病(LBL/ALL)的细胞病理学诊断线索及意义。方法收集郑州大学第一附属医院2011年8月至2019年12月确诊为LBL/ALL的浆膜腔积液标本45例,观察并总结其临床特点及细胞形态学特征,其中22例标本被制成细胞块并行免疫细胞化学检测,3例行流式细胞术检测,5例行T细胞受体(TCR)和免疫球蛋白(Ig)基因重排分析。结果45例病例中男性35例,女性10例,男女比为3.5∶1.0,中位年龄15岁。39例(86.7%)患者有纵隔肿块,34例(75.6%)患者伴有血清乳酸脱氢酶(LDH)的增高;显微镜下,细胞量较为丰富,弥漫散在分布;细胞成分相对单一,小至中等大小;细胞核形不规则或曲核,可见核裂或乳头状突起,染色质细,核仁不明显;核分裂象易见;胞质少或无,背景均可见到核碎裂及凋亡小体。22例细胞块免疫表型为19例(86.4%)表达末端脱氧核苷酸转移酶(TdT),20例(90.9%)表达CD99,Ki-67阳性指数65%~95%。行流式细胞术检测的3例标本均显示TdT、CD2、CD3和CD7高表达的异常T细胞,行基因重排检测的5例标本中,4例呈TCR单克隆重排,1例同时发现TCR和Igκ单克隆重排。结论结合临床特征(青少年男性伴有纵隔肿块)和细胞形态特点(大量散在分布的形态单一的中小淋巴细胞,明显的核形不规则,染色质细腻,易见核分裂象、核碎裂及凋亡小体),可以对浆膜腔积液LBL/ALL进行初步诊断,辅以免疫细胞化学结果及其他辅助检测技术可进一步提高LBL/ALL诊断的准确性和可靠性。     

甲状腺病变累及至上纵隔的MDCT表现特征及其解剖、病理学基础

为了明确甲状腺病变累及至上纵隔的多层螺旋CT(MDCT)影像表现特点及其解剖、病理学基础,回顾性收集经临床病理证实的累及至上纵隔的甲状腺病变49例(其中结节性甲状腺肿22例,甲状腺瘤13例,甲状腺癌14例),结合其解剖、病理学基础,分析其MDCT表现特征及优势解剖分布。结果发现甲状病变向下位于前上纵隔约占67.3%(33/49)、后上纵隔14.3%(7/49)、跨前后纵隔18.4%(9/49);不同性质病变有各自特征性的MDCT表现:结节性甲状腺肿以局限多发结节、肿块为主,约占77.3%(17/22);甲状腺腺瘤以单发肿块为主,约占92.3%(12/13);甲状腺癌以单发肿块为主,约占57.1%(8/14),9例合并有颈部和(或)纵隔淋巴结转移。因此,甲状腺病变累及至上纵隔,位于前上纵隔多见,后纵隔少见,其影像学表现及优势解剖分布与其解剖、病理基础密切相关。     

淋巴结边缘区B细胞淋巴瘤临床病理学特点及BRAF V600E和MYD88 L265P基因突变分析

目的探讨淋巴结边缘区B细胞淋巴瘤(NMZL)临床病理学特点及BRAF V600E和MYD88 L265P基因突变情况。方法收集2009年9月至2021年2月河南省人民医院病理科及北京大学医学部病理学系诊断的NMZL 32例, 分析其临床病理学特点, 聚合酶链反应(PCR)检测BRAF V600E基因及Sanger测序法检测MYD88 L265P基因突变情况。结果患者男性20例, 女性12例, 中位年龄69岁(范围36～82岁), 临床表现为多发淋巴结肿大, 头颈部淋巴结最多见(22/32, 68.8%), 其次为腹股沟(12/32, 37.5%)、腋窝(11/32, 34.4%)、纵隔(5/32, 15.6%)、腹膜后淋巴结(4/32, 12.5%)。患者多处于Ann Arbor分期Ⅰ/Ⅱ期(21例)。形态学表现为弥漫型(24/32, 75.0%)、结节型(5/32, 15.6%)、滤泡间型(2/32, 6.3%)及滤泡周型(1/32, 3.1%)的生长模式, 肿瘤细胞呈单核细胞样、中心细胞样、小淋巴细胞样及不同程度的浆细胞样分化。免疫表型:肿瘤细胞弥漫表达CD20, 部分表达CD43...     

24例年轻人结外NK/T细胞淋巴瘤(鼻型)的临床病理特征分析

目的探讨一组年龄≤40岁结外NK/T细胞淋巴瘤(鼻型)(extranodal natural killer/T-cell lymphoma,nasal type,ENKTL)的临床病理特征。方法收集海南医学院第一附属医院、海南省人民医院和海口市人民医院病理科2004年1月~2017年2月收治的年龄≤40岁ENKTL病例共24例,应用免疫组化检测CD20、CD3、CD5、CD56、TIA-1、Granzyme B和Ki-67在ENKTL中的表达,应用EBER原位杂交检测EBV表达,同时收集临床数据,分析该组病例的临床病理特征及预后。结果本组年龄≤40岁的ENKTL病例中,患者年龄15~40岁,中位年龄29岁,男女比为2∶1。免疫表型:CD20、CD5(-),CD3、CD56、TIA-1和Granzyme B(+),Ki-67增殖指数30%~95%,EBER原位杂交肿瘤细胞均阳性;肿瘤原发部位主要位于上呼吸道,尤其多见于鼻腔及鼻咽部;中位生存期21个月,预后与病变部位(鼻或鼻外)、是否同时伴有其他疾病及是否接受治疗相关。结论本组≤40岁ENKTL病例具有与其他年龄组相似的临床病理特征,伴有较高的HBV感染率,中位生存时间21个月,预后与病变部位(鼻或鼻外)、是否同时伴有其他疾病及是否接受治疗相关。     

淋巴浆细胞性淋巴瘤的临床病理特点分析

目的 探讨淋巴浆细胞性淋巴瘤(LPL)的临床及病理学特点及其鉴别诊断和与Waldenstr(o)m巨球蛋白血症的关系.方法 24例骨髓活检标本,6例同时行淋巴结活检,行石蜡包埋切片、HE染色形态观察及免疫组织化学EliVision法检测分析.结果 男17例,女7例(男:女=2.4:1).中位年龄59.5岁(42～75岁).临床表现以乏力最多见,为83.3%(20/24).高黏滞血症20.8%(5/24),B症状8.3%(2/24),浅表淋巴结肿大41.7%(10/24).贫血79.2%(19/24),白细胞增高8.3%(2/24),血小板减少37.5%(9/24).血清免疫固定电泳显示23例(95.8%)出现单克隆性免疫球蛋白轻链条带,IgM型20例、IgG型2例、IgA型1例.22例骨髓活检和2例淋巴结活检均经病理组织形态和免疫组织化学诊断为LPL,骨髓及淋巴结瘤细胞由小淋巴细胞、浆细胞样淋巴细胞及浆细胞组成;侵犯骨髓的方式多为弥漫型(63.6%,14/22),结节型及间质型少见分别为22.7%(5/22)及13.6%(3/22).淋巴结瘤细胞呈弥漫性分布.瘤细胞表达Pax5、CD20、CD38、CD138,不表达CD5、CD10、CD23、细胞周期蛋白D1、CD3、CD7、髓过氧化物酶.结论 LPL具有明确的临床及病理学特点,诊断应主要结合组织形态和免疫表型与慢性淋巴细胞白血病/小细胞淋巴瘤、脾脏边缘区淋巴瘤及滤泡性淋巴瘤等小淋巴细胞肿瘤鉴别.Waldenstr(o)m巨球蛋白血症的本质为LPL.     

38例儿童Langerhans细胞组织细胞增生症临床病理观察

目的探讨儿童Langerhans细胞组织细胞增生症(Langerhans cell histiocytosis,LCH)的临床特点、病理形态学及免疫表型特征,并分析其与预后的关系。方法分析38例儿童LCH的临床及病理资料,其中18例做了免疫组化染色。结果在38例儿童LCH中,单发为30例(占78·9%),多发为8例(占21·1%)。病变发生于骨组织34例(占89·5%)(其中1例伴有皮肤病变),发生于皮肤组织3例,发生于淋巴结1例。镜下病变主要由Langerhans细胞及嗜酸性粒细胞组成。免疫组化结果显示Langerhans细胞阳性表达CD1a为100%(13/13),S-100蛋白为88·2%(15/17),vimentin为90·0%(9/10),CD68为81·8%(9/11),Mac387为30·0%(3/10),lysozyme为40·0%(4/10),CK、EMA、CD45均阴性。结论儿童LCH最多发生于骨组织,在病理学上具有特殊的形态学表现以及免疫组化表型。疾病的预后与病理分型及临床分级有关。     

LAT和CD99在T淋巴母细胞淋巴瘤中的表达及意义

目的 探讨LAT和CD99在T淋巴母细胞淋巴瘤(precursor T lymphoblastic lymphoma,T-LBL)中表达的价值.方法 对37例T-LBL应用免疫组织化学EnVision二步法进行LAT和CD99标记.同时选取15例其他病例作为对照:3例B淋巴母细胞淋巴瘤,4例非特殊类型外周T细胞淋巴瘤,3例结外鼻型NK/T细胞淋巴瘤,5例淋巴结反应性增生.结果 37例T-LBL均表达LAT和CD99;4例外周T细胞淋巴瘤及3例鼻型结外NK/T细胞淋巴瘤弥漫表达LAT,不表达CD99;3例B淋巴母细胞淋巴瘤均表达CD99,但不表达LAT;5例反应性增牛淋巴结的T细胞区LAT阳性,淋巴结皮、髓质区均不表达CD99.结论 联合检测LAT和CD99有助于T-LBL的诊断和鉴别诊断.     

Expression of the promyelocytic leukemia zinc-finger in T-lymphoblastic lymphoma and leukemia has strong implications for their cellular origin and greater association with initial bone marrow involvement

The promyelocytic leukemia zinc-finger (PLZF) is essential for the development of innate T cells (as represented by natural killer T cells) for acquisition of their unique innate immune properties. We evaluated the PLZF protein expression in a variety of immature and mature lymphoid malignancies. PLZF was preferentially expressed in T-lymphoblastic lymphoma/acute lymphoblastic leukemia (T-LBL/ALL) in 50% of the 54 cases. Among 51 cases of peripheral T-cell lymphoma not otherwise specified, only one (2%) expressed PLZF. One mycosis fungoides case expressed PLZF in lymph node involved by tumor. Otherwise, PLZF was not detected in any other type of lymphoma. In T-LBL/ALL, PLZF expression was more common in CD4/CD8 double-negative (67%) or CD8 single-positive subtypes (73%) than in CD4/CD8 double-positive (13%) and CD4 single-positive subtypes (0%) (P=0.001). Importantly, PLZF and CD1a expression were mutually exclusive in T-LBL/ALL (P=0.001). This was also the case for T-cell receptor βF1 expression (P=0.000). Most (96%) of the PLZF-positive T-LBL/ALL cases showed initial bone marrow involvement compared with 39% of PLZF-negative cases (P=0.000). Based on these findings, we suggest that T-LBL/ALLs that express PLZF arise from early immature double-negative thymocytes when the T-cell receptor β chain has not yet expressed or innate T-cell precursors, and strongly imply bone marrow involvement.     

Expression and significance of CD47, PD1 and PDL1 in T-cell acute lymphoblastic lymphoma/leukemia

Although dose intensi?cation strategies achieve a favorable prognosis for pediatric patients of T-lmphoblastic lymphoma/leukemia (T-LBL/ALL), numerous side effects have been followed. Molecular targeted therapies will be needed to optimize the current treatment strategy for T-LBL/ALL. The aim of this study was to analyse expression and significance of CD47, PD1 and PDL1?in. T-LBL/ALL. We performed immunohistochemistry staining and real time fluorescence quantitative PCR (qRT-PCR) on FFPE tissues. Immunohistochemistry results showed that the high expression rate of CD47 protein was 46.4% (26/56) and the positive expression rate of PDL1 protein was 37.5% (21/56). PD1 expression was observed in tumor infiltrating lymphocytes in approximately 20% of T-LBL/ALL patients, but not expressed on tumor cells of T-LBL/ALL. And the results of qRT-PCR showed that the relative expression levels of CD47, PDL1 and PD1 mRNA in 56 cases of T LBL/ALL were significantly higher than those in control group (6.915 vs 4.050, 12.255 vs 2.575, 37.990 vs 3.615), and the differences were all statistically significant (p all <0.05). Univariate analysis showed that age, CD47 protein, CD47 mRNA,PDL1 protein and PDL1 mRNA expression were closely correlated with prognosis (P all <0.05). We found that the overall one-year survival rates of patients with a high expression (≥M) of CD47 and PDL1 mRNA were higher than in patients with low expression (<M). However, the overall one-year survival rate of patients with a high expression (≥M) of CD47 and PDL1 protein were lower than in patients with low expression (<M). And patients with ≤25 years old had a worse prognosis than with >25 years old. Multivariate Cox regression analysis showed that the high expression of CD47 and PDL1 protein were independent prognostic factors (both p?<?0.05). In a word, PD1/PDL1 and CD47 may be involved in the disease progression and prognosis of T-LBL/ALL, and detection and targeting of CD47 and PD1/PDL1 may provide a rational basis to for treatment of T-LBL/ALL.     

Significance of microRNA-16 and bcl-2 expression in T lymphoblastic lymphoma/leukemia and its relation with prognosis北大核心CSCD

Objective: To study the expression of miR-16 and bcl-2 in T lymphoblastic lymphoma/leukemia (T-LBiyALL) and its relationship to prognosis. Methods: 70 cases of T-LBL/ALL with follow-up data were studied by using immunohistochemical EnVision method for CDla,CD3, cCD3, CD7, CD10, CD20, CD23, CD34, CD43, CD45RO, CD99, TDT, MPO, bcl-2 and Ki-67. The expression levels of miR-16 were examined by TaqMan real-time polymerase chain reaction (RT-PCR). Thirty cases of reactive lymph node were selected as control. Results: Among the 70 cases of T-LBL/ALL, the percentages of tumor cells expression of TDT, CD99, CD3, CD7.CD10, CD34, CDla,cCD3, bcl-2, CD45RO and CD43 were 94. 3% (66/70), 94. 3% (66/70), 68. 6% (48/70), 92. 9% (65/70), 32. 9% (23/70), 24. 3% (17/70), 40. 0% (28/70), 51. 4% (36/70), 34. 3 % (24/70), 37. 1 % (26/70), and 48. 6% (34/70). Separately, while tumor cells expression of MPO, CD20 and CD23 was all negative. A figure of Ki-67 expression > 80% was found in 24 cases and ≤ 80% in 46 cases. The expression of miR-16 was up-regulated in T-LBL/ALL, and it was 5. 07 times of the reactive lymph node(P = 0. 001). The high expression group of miR-16 was significantly correlated with longer over survival (P = 0. 041). The prognosis of negative bcl-2 group was better than bcl-2 positive one(P =0. 904). The relationship of miR-16 and bcl-2 was significant P =0. 042, x2=4. 147). Survival multivariate COX proportional hazard regression analysis revealed that the low expression of miR-16 might be a independent poor prognosis factor (P =0.049). Conclusions: While the high expression group of miR-16 has longer OS than that in low expression group. The prognosis of bcl-2 negative was better than bcl-2 positive. miR-16 may be a independent prognosis factor. The relationship of miR-16 and bcl-2 might suggested that gene regulation may be influenced by them.     

Differential expression of cyclin-dependent kinase 6 in cortical thymocytes and T-cell lymphoblastic lymphoma/leukemia.

Cyclin-dependent kinase-6 (CDK6) is the earliest inducible member of the CDK family in human T lymphocytes, involved in growth factor stimulation and cell cycle progression. CDK6 is one of the targets of p16 and p15, CDK inhibitors encoded by MTS1 and MTS2, two tumor suppressor genes that are frequently deleted in T-cell leukemia. In this study we have investigated CDK6 expression in normal and neoplastic lymphoid tissues using immunohistochemistry and flow cytometry. In normal (six samples) and hyperplastic (four samples) thymuses, strong CDK6 expression was observed in a discrete proportion of cortical thymocytes (10 to 15%), mainly located in the peripheral (subcapsular) zone of the cortex. All tested cases of T-cell lymphoblastic lymphoma/leukemia (T-LBL/ALL) showed strong CDK6 expression in the majority (up to 100%) of neoplastic lymphoid cells. Western blot analysis confirmed the expected CDK6 protein size (40 kd). According to Southern blot analysis, CDK6 overexpression in neoplastic T lymphoblasts was not due to gene amplification. In all other lymphomas investigated (28 peripheral T-cell non-Hodgkin's lympohomas (T-NHLs), 7 CD30+ anaplastic NHLs, 22 high-grade B-NHLs, 15 low-grade B-NHLs, 25 B-cell precursor ALLs), CDK6 was not expressed or expressed at low levels, with the only exception of three nasal angiocentric T-NHLs, all exhibiting CDK6 immunoreactivity comparable to that observed in T-LBL/ALL. These data provide evidence that CDK6 is abnormally expressed in T-LBL/ALL and may be involved in the pathogenesis of this malignancy. In addition, the quantitative difference of CDK6 expression between neoplastic and non-neoplastic cortical thymocytes can be potentially useful in the differential diagnosis of thymic neoplasms on histological and cytological specimens.     

Lineage determination of CD20- B-Cell neoplasms: an immunohistochemical study

We studied 61 CD20- B-cell lymphomas, including 29 cases of precursor B-cell lymphoblastic leukemia/lymphoblastic lymphoma (B-ALL/B-LBL), 25 cases of CD20- recurrent mature B-cell lymphoma after rituximab therapy, and 7 cases of CD20- diffuse large B cell lymphoma (DLBCL). We used markers specific for B lineage: CD79a, Pax-5, OCT.2, and BOB.1. All B-ALL/B-LBLs expressed Pax-5 (29/29 [100%]), 25 (93%) of 27 expressed BOB.1, 23 (79%) of 29 expressed CD79a, and 6 (22%) of 27 expressed OCT.2. The percentages of cases expressing Pax-5, CD79a, OCT.2, and BOB.1 in CD20- recurrent mature B-cell lymphomas after rituximab treatment were 88% (21/24), 84% (21/25), 81% (17/21), and 73% (16/22), respectively. CD20- DLBCLs rarely express routine B-lineage markers, such as and CD79a and Pax-5, but they expressed OCT.2 or BOB.1. Pax-5, BOB.1, and CD79a antigens are the most reliable B-lineage markers for paraffin immunophenotyping B-ALL/B-LBL. CD79a and Pax-5 should be used as the first-line B lineage-specific markers for rituximab-treated CD20- mature B-cell lymphomas. If negative, OCT.2 or BOB.1 may be useful. The newly identified B-lineage markers, OCT.2 and BOB.1, may be the most useful for the B-lineage determination of CD20- plasmablastic or primary effusion subtypes of DLBCL.     

TDT (-), KIT (+), CD34 (+), CD99 (+) precursor T lymphoblastic leukemia/lymphoma

Although the definition of precursor T lymphoblastic lymphoma (T-LBL) is based only on histopathology, most cases cannot be diagnosed only by HE sections. Since 95% of T-LBL expresses TdT and TdT is expressed only in lymphoblasts, immunohistochemical demonstration of TdT is mandatory for the diagnosis of TLBL. However, little is known about the expression of other precursor cell molecules. A 58-year-old woman with myelodysplastic syndrome (RAEB) became overt acute myelogenous leukemia (AML). She was treated twice with allogeneic peripheral blood stem cell transplantation from her son. Nine months later, imaging modalities detected a soft tissue tumor around the left ileal bone. A biopsy was performed. Histologically, the tumor cells were malignant polymorphic lymphoid cells with hyperchromatic nuclei and inconspicuous nucleoli. Immunohistochemically, the tumor cells are positive for CD45, CD45RO, CD34, KIT (CD117), CD99 (MIC-2), p53, CD10, PDGFRA, and Ki67 (labeling=60%). They were negative for pancytokeratin AE1/3, pancytokeratin CAM5.2, TdT, CD3, CD20, CD79α, CD43, CD56, CD57, CD30, bcl-2, κ-chain, λ-chain, cytokeratin (CK) 7, CK20, synaptophysin, chromogranin, smooth muscle actin, p63, MPO, CD68, lysozyme, and ASD esterase. Although TdT was negative, other precursor cell markers (KIT, CD34, and CD99) were positive and the lymphoid cells showed T-cell lineage, the diagnosis was T-LBL. The patient died of lymphoma/ leukemia 11 months after the diagnosis. The author stress that TdT, KIT, CD34 and CD99 should be included in panels of precursor T-cell neoplasms. In addition, the author think that KIT, CD34 and CD99 are helpful for the diagnosis of T-LBL in cases negative for TdT. Further, it is unique that this case was not myeloid sarcoma but precursor T-cell neoplasm, and that T-LBL develops during AML.     

Aberrant myeloid marker expression in precursor B-cell and T-cell leukemias

The World Health Organization (WHO) characterization of the immunophenotype of precursor B-cell acute lymphoblastic leukemia (pre-B ALL) includes the possible expression of myeloid cluster of differentiation (CD) markers CD13 and CD33. In precursor T-cell acute lymphoblastic leukemia (pre-T ALL), myeloid markers CD13 and CD33 are frequent while CD117 is rare. In the present investigation, 71 cases of confirmed pre-B ALL were evaluated for the presence of CD13 and CD33. Of the 19 (27%) cases that positively expressed myeloid markers, 10 (53%) expressed CD13, 17 (89%) expressed CD33, and 1 (5%) expressed CD117. Eight (42%) expressed both CD13 and CD33, and 1 (5%) expressed CD13, CD33, and CD117. Twenty-one cases of confirmed pre-T ALL were analyzed for myeloid markers CD13, CD33, CD117, and MPO. Of the 6 (29%) expressing myeloid markers, 4 (67%) were positive for CD13, 4 (67%) for CD33, 3 50(%) for CD117, and 1 (17%) for MPO. One (17%) was positive for both CD13 and CD117; one (17%) for CD13 and CD33; one (17%) for CD13, CD33 and CD117; and one (17%) for CD13, CD33 and MPO. These markers portend a poor prognosis compared to ALL cases without myeloid antigens, and a poor response to drug therapies targeting conventional ALL. Future studies will be directed to correlation of these markers with prognosis and therapeutic response, as well as whether drug therapies targeting myeloid antigens could be of use in treatment.