毛细胞白血病细胞表面糖蛋白三聚体的免疫电镜检测

目的 为毛细胞白血病(hairy cell leukemia，HCL)的诊断提供新方法。方法 采用对毛细胞白血病有高度特异性的单抗B-ly-7(CD103)对5例患者毛细胞表面的糖蛋白三聚体(trimeric glycoprotein，TGP)进行免疫电镜研究。结果 4例HCL患者毛细胞表达TGP，镜下显示细胞胞质突起呈现出清晰的黑色边缘，与邻近染色阴性的细胞形成明显区别。而1例伴绒毛淋巴细胞的脾淋巴瘤(splenic lymphoma with villous lymphocytes，SLVL)和6例B淋巴细胞慢性白血病(B-chronic lymphocytic leukemia，B-CLL)均显示阴性。结论 免疫电镜检测毛细胞膜上的TGP有助于毛细胞白血病的鉴别诊断。     

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.     

淋巴母细胞淋巴瘤/白血病临床病理、免疫表型及预后相关性研究

目的 探讨淋巴母细胞淋巴瘤/急性淋巴母细胞白血病(LBL/ALL)临床病理、免疫组织化学特征并行预后相关性分析.方法 回顾性研究153例LBL/ALL患者的临床病理资料,根据临床和随访结果,对其预后与免疫表型、Ann Arbor分期、纵隔肿块、骨髓受累、肝脾肿大、Ki-67指数以及患者年龄、性别多因素进行相关性研究.结果 TdT和CIY99阳性率分别为79.1%(121/153例)和96.3%(131/136例).按免疫表型分为T-、B-LBI/ALL及未定类.(1)T-LBL/ALL占69.3%(106/153例),男75例,女31例,中位年龄17.5(2～68)岁,92例(86.8%)表现为外周淋巴结肿大,其中59例(55.7%)伴有纵隔肿块,91例(85.8%)为Ⅲ～进展期.1年与5年生存率分别为36.1%和8.1%,年龄大于25岁(P=0.049)、Ⅲ～Ⅳ期(P=0.001)是T-LBL/ALL预后不良的指征.(2)B-LBL/ALL占19.O%(29/153例),男18例,女11例,中位年龄14岁(9个月～75岁),17例(58.6%)表现为外周淋巴结肿大,其中13例(44.8%)有骨髓或外周血受累,5例(17.2%)伴有纵隔病变,21例病变处于Ⅲ～Ⅳ期.1年与5年生存率分别为53.3%和36.7%.(3)未定类组为11.7%(18/153例),所检抗体如CD3ε/CD3、CD45RO、CD79a、CD20、髓过氧化物酶(MPO)、CD5、CD56、cyclin D1、CK、神经元特异性烯醇化酶(NSE)、嗜铬粒素A(CgA)和突触素(Syn)均阴性.男13例,女5例,中位年龄15.5(4～53)岁,原发淋巴结病变15例(83.3%),7例(38.9%)有纵隔病变.(4)与B-LBL/ALL比较,T-LBI/ALL患者伴有纵隔肿块较为常见(P=0.0003),中位生存期短[分别为(15.0±7.0)个月和(6.0±1.1)个月],但差异无统计学意义(P=0.07).结论 TdT与CD99是前驱淋巴细胞重要的特异性标志物;T-LBL/ALL多见于青少年男性,常伴有纵隔占位及浅表或多处淋巴结肿大;B-LBL/ALL易累及骨髓或外周血;T-LBL/ALL预后较差,年龄和临床分期是影响T-LBL/ALL患者生存的重要预后参数.     

淋巴浆细胞性淋巴瘤伴Waldenstrom巨球蛋白血症的临床病理和免疫表型分析

目的 探讨淋巴浆细胞性淋巴瘤伴Waldenstrom巨球蛋白血症的临床病理学特征及预后,了解其免疫表型在病理诊断和鉴别诊断中的作用.方法 根据2008版WHO淋巴造血组织肿瘤分类收集40例淋巴浆细胞性淋巴瘤伴Waldenstrom巨球蛋白血症患者临床及随访资料,对标本进行免疫表型检测(SP法)及PAS、甲苯胺蓝、刚果红特殊染色.结果 患者年龄40～90岁,中位年龄64岁.患者多以疲乏、贫血和出血倾向就诊.淋巴结、脾脏和肝脏肿大比率分别为42.5%、20.0%和12.5%.36例骨髓浸润模式表现为混合型(17例)、弥漫型(15例)和间质型(4例).9例淋巴结,1例结构完全破坏,8例部分破坏,可见扩张的淋巴窦和残存的淋巴滤泡.骨髓组织与淋巴结组织免疫表型结果基本一致.肿瘤性小淋巴细胞表达CD20和CD79a,浆细胞表达CD79a和CD138.所有病例均不表达CD5,仅4例弱表达CD23.生存分析显示不同的骨髓浸润模式、白蛋白值、血小板计数、白细胞计数、血清IgM值对患者生存时间均未见影响.结论 淋巴浆细胞性淋巴瘤伴Waldenstrom巨球蛋白血症为一种少见的好发于老年人的惰性小B细胞淋巴瘤,临床表现多样化.骨髓活检形态学观察、免疫表型分析及临床资料(尤其是血清学检查)对于其临床病理诊断至关重要.     

毛细胞白血病(HCL)NK活性减低:细胞水平分析

毛细胞白血病(HCL)是以毛细胞(HC)浸入骨髓、外周血和脾脏为特征的淋巴细胞增殖性疾病。仅仅最近,人们才提出足够的根据证明HC是B淋巴细胞产生的。尽管在这一增殖性疾病中含有大量的相当成熟的B淋巴细胞,但在未治疗的HCL病人,其T细胞亚群的分布却明显的不平衡。著者用~(51)Cr释放试验和单细胞毒性试验     

骨髓增生异常综合征中CD117、CD15表达的诊断价值

目的探讨骨髓增生异常综合征(myelodysplastic syndrome, MDS)中CD117、CD15表达的诊断价值。方法收集26例MDS为实验组,23例髓系白血病(myeloid leukemia, ML)作为对照组,包括18例急性髓系白血病(acute myeloid leukemia, AML)和5例慢性髓系白血病(chronic myeloid leukaemia, CML)。应用免疫组化EnVision两步法观察两组CD117和CD15的表达差异,根据免疫形态分为4种模式:Ⅰ型(散在阳性)、Ⅱ型(簇状阳性)、Ⅲ型(斑驳状阳性)、Ⅳ型(弥漫阳性)。结果 MDS组CD117的Ⅱ型阳性率(57.69%)高于ML组(P均0.05),其诊断灵敏度为57.69%,特异度分别为94.44%(与AML相比)、100%(与CML相比)。MDS组CD15的Ⅲ型阳性率(100%)高于AML(0)、CML(0)组(P均0.05),其诊断灵敏度、特异度均为100%。MDS组巨核细胞数量和单圆核/多圆核巨核细胞的阳性率(25.08±15.60,69.23%)高于AML组(10±10.35,21.74%)(P0.05)。结论 CD117和CD15的免疫形态对MDS和ML的鉴别诊断具有辅助意义。     

侵袭性NK细胞白血病的临床病理学特点

目的 探讨侵袭性NK细胞白血病(ANKL)的临床病理学特点.方法 回顾性分析10例ANKL患者的临床病理档案资料,全部病例均行全血细胞计数以及外周血涂片、骨髓穿刺与骨髓活检标本的形态学观察.用流式细胞学(FCM)及免疫组织化学(EliVision法)进行免疫表型分析.聚合酶链反应(PCR)法检测T细胞受体(TCR)γ基因重排.结果 10例患者中,最常见的血液学异常为贫血(7例)与血小板减少(9例).6例外周血涂片可见大颗粒淋巴细胞.骨髓穿刺涂片示8例淋巴细胞比例增高(＞20.0％).6例可见大颗粒淋巴细胞.骨髓活检切片示轻度浸润5例,中度浸润3例,重度浸润2例.骨髓切片中8例为间质型浸润,2例呈弥漫型浸润,4例可见噬血现象(吞噬成熟红细胞).免疫表型方面,FCM检测示全部病例为CD2+sCD3- CD4- CD56+CD57-.9例CD7、5例CD16、4例CD8和1例CD5阳性.8例行免疫组织化学相关抗原检测:cCD3 4例、CD566例、T细胞内抗原1(TIA-1)6例、颗粒酶B4例和穿孔素2例阳性.10例TCRγ基因重排检测均为胚系构型.结论 ANKL是一种NK细胞来源的高度侵袭性淋巴组织肿瘤,需进行全面的外周血与骨髓的形态学、免疫表型以及分子遗传学检测才能确诊,需注意与多种NK细胞与T细胞淋巴瘤鉴别.     

脾B细胞边缘区淋巴瘤的临床病理观察

目的 分析和总结脾边缘区B细胞淋巴瘤(SMZL)的临床病理特点、探讨其诊断与鉴别诊断要点.方法 对8例原发性SMZL的临床资料行回顾性分析总结、组织切片的形态观察和免疫组织化学EliVision法染色分析,并对部分病例行基因重排克隆性检测,获得4例随访资料.结果 8例SMZL的中位年龄为61.5岁(36～75岁),男女比例为1.7:1.患者均因脾大就诊,5例伴血象异常,白细胞和血小板均低于正常,其中2例全血细胞下降.脾切除后3例血象全部或部分恢复正常.3例福达华联合化疗后,2例完全缓解,1例死亡.随访4例的平均生存期21.5个月(6～60个月).在病理形态上,8例脾脏均呈白髓结节状增生,其中6例由经典的两种细胞组成,其分布表现为结节中央密集而深染的小淋巴细胞,周围为不典型单核细胞样细胞.2例增生结节全部由形态一致的不典型单核细胞样细胞组成.红髓区片状浸润8例.肿瘤细胞CD20+(8例);bcl02+(6/6),IgD+(2/4),CD5+(1/4),CD43-(516),cyclin D1-和bcl-6/CD10-(6/6).核增殖指数<15%.结论 SMZL为惰性淋巴瘤,以脾大伴血象异常为主要临床表现.脾切除治疗有效,FCD化疗可完全缓解,预后较好.病理形态以白髓结节状增生为主,呈不典型单核细胞样细胞形态,大部分标本结节中央见较小密集的淋巴细胞,同时存在红髓区片状浸润.诊断需除外其他小B细胞淋巴瘤和脾白髓增生.     

人参皂苷Rg1对白血病干细胞衰老的影响

目的对比健康人群造血干细胞(HSCs)与白血病患者HSCs衰老的生物学特征,并探讨人参皂苷Rg1对促进白血病干细胞衰老的效果,为白血病的防治提供新的思路和方法。方法取正常人骨髓15例(正常组),慢性髓细胞白血病患者骨髓16例(白血病组),正常组与白血病组分别再分为对照组与Rg1组。对照组进行常规培养;Rg1组在培养体系中加10μg/m L的人参皂苷Rg1,其他条件同对照组。2 d后提取各组人骨髓单个核细胞(BMNCs),免疫磁性吸附细胞分选法(MACS)分离纯化出CD34~+/CD38~-细胞群,流式细胞术检测细胞纯度,台盼蓝染色检测细胞活性,流式细胞术检测细胞周期时相,衰老相关β-半乳糖苷酶(SA-β-gal)染色观察各组阳性细胞百分比,CCK-8检测各组CD34~+/CD38~-增殖能力。结果分选前每1×106个BMNCs中CD34~+/CD38~-细胞群比例为(1.76±0.34)%;免疫磁性分选后每1×106个细胞中CD34~+/CD38~-细胞群比例为(91.15±2.41)%。白血病Rg1组人骨髓CD34~+/CD38~-细胞的SA-β-gal染色阳性率明显高于白血病对照组,差异具有统计学意义(P0.05);正常对照组与正常Rg1组比较,差异无统计学意义(P0.05),但均高于白血病对照组,差异具有统计学意义(P0.05)。CCK-8结果显示,白血病对照组CD34~+/CD38~-细胞增殖速度明显增加,高于其余各组,差异具有统计学意义(P0.05)。各组人骨髓CD34~+/CD38~-细胞存活率可达99.1%以上。细胞周期时相结果显示,白血病对照组CD34~+/CD38~-细胞G1期阻滞明显低于其余3组,差异具有统计学意义(P0.05)。结论慢性髓细胞白血病患者骨髓CD34~+/CD38~-细胞增生活跃,出现明显逆衰老现象,这可能是造成一些慢性髓细胞白血病的原因之一,而人参皂苷Rg1可以通过促进白血病干细胞衰老延缓这一过程。     

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.     

Hairy cell leukemia-variant--a case report

Hairy-cell leukemia-variant (HCL-V) is a rare B-cell disorder which accountsfor 10% of HCL cases. The main features are splenomegaly, lymphocytosis and cytopenias without monocytopenia. The circulating cells have a morphology intermediate between prolymphocytes and hairy cells. The immunophenotype shows a mature B-cell phenotype with expression of B-cell antigens CD11c and CD103 but unlike typical hairy cell the cells are negative for CD25. The histology of bone marrow and spleen shows a pattern of infiltration similar to that in HCL. We present a case of HCL-V in a 66-year-old male. The bone marrow findings, immunophenotypic profile and electron microscopic features are described. The patient underwent splenectomy which also revealed infiltration by leukemia. Patients are resistant to alkylating agents and alpha-interferon (á-IFN). Splenectomy may be beneficial for long-lasting partial responses in some of the patients and is a good palliative treatment.     

Hairy cell leukemia and variant in Taiwan: report of a variant case and literature review

Hairy cell leukemia (HCL) is characterized by leukemic cells with abundant "hairy" cytoplasm, strong cytoplasmic positivity for tartrate-resistant acid phosphatase (TRAP), characteristic immunophenotype and sensitivity to treatment with purine nucleoside analogs. HCL-variant (HCL-v) encompasses chronic B-cell leukemias resembling classical HCL but exhibiting variant cytomorphology, variant immunophenotype and resistance to conventional HCL therapy. We present the case of a 67-year-old Taiwanese male with HCL-v who had leukocytosis and splenomegaly. His hairy leukemic cells were weakly positive for TRAP and expressed CDllc and CD103 but not CD25. He received oral chemotherapy with chlorambucil and in complete hematological remission in 9 months but relapsed 2 months later. Literature review revealed 9 cases of HCL and 3 cases of HCL-v including current case from Taiwan. All patients were adults with splenomegaly. The HCL patients had a significantly higher frequency of leukopenia (p = 0.024) and monocytopenia (p = 0.008) and a lower frequency of leukocytosis (p = 0.018) than HCL-v patients. All 8 HCL patients responded favorably to 2-chlorodeoxyadenosine with or without splenectomy. The 3 HCL-v patients had leukocytosis and received chemotherapy with variable outcome. HCL and HCL-v are rare in Taiwan and their pathological and immunophenotypical features were not fully characterized. A multimodality approach incorporating hematological findings, cytomorphology, histopathology, cytochemistry, complete immunophenotyping and clinical features is needed to identify and characterize such cases in Taiwan.     

Diagnostic relevance of peripheral blood immunocytochemistry in hairy cell leukaemia.

AIMS--(1) To assess the diagnostic relevance of peripheral blood immunocytochemistry in hairy cell leukaemia (HCL); (2) to compare the immunostaining of bone marrow biopsy specimens with bone marrow and peripheral blood cytospins; (3) to evaluate the sensitivity of the different markers used; (4) to identify the ultrastructural localisation of DBA.44 in HCL variant. METHODS--Immunoenzymatic staining procedures, immunoperoxidase and immunoalkaline phosphatase, were used with a panel of monoclonal antibodies directed to HCL associated antigens. Ultrastructural immunostaining was performed using colloidal gold conjugated antibodies. RESULTS--HCL showed strong cytoplasmic reactivity for CD22, CD25, CD103, DBA.44, kappa, or lambda light chains. Peripheral blood diagnostic hairy cells were found in all the cases with absolute counts ranging from 0.11 x 10(9)/l up to 6.4 x 10(9)/l and values increasing with the size of the spleen. A median of 36.5% of leukaemic cells was found in bone marrow aspirates and 70% in bone marrow trephine specimens. The monoclonal antibodies CD22 and DBA.44 showed the highest and the lowest percentage of positive hairy cells, respectively; this difference was statistically significant (p = 0.0025). Ultrastructural immunolabelling with DBA.44 showed a cytoplasmic membrane localisation of the antigen in one case of HCL variant. CONCLUSIONS--(1) Immunocytochemistry is a useful technique which enhances the accuracy of diagnosis in HCL; (2) peripheral blood immunocytochemistry is recommended because it highlights hairy cells in all cases; (3) CD22 appears to be the most sensitive of the markers tested; (4) ultrastructural analysis is a useful tool in selected cases of HCL variant.     

Transformation of hairy cell leukemia to high-grade lymphoma: a case report and review of the literature

The coexistence of hairy cell leukemia (HCL) and non-Hodgkin's lymphoma is extremely rare. In the few reports demonstrating such coexistence, the relationship between the 2 entities was mostly inconclusive. We report a case of HCL that transformed to large cell lymphoma. This case has been followed for more than 4 years with immunohistochemical, flow cytometric, and molecular genetic studies on multiple bone marrow biopsy specimens, a splenectomy specimen, and a lymph node biopsy. In our case, the immunophenotype and tartrate-resistant acid phosphatase stain confirmed that the large cell lymphoma was of HCL origin. The markedly increased Ki-67 staining (proliferation fraction) in the lymph node biopsy specimen compared to the earlier splenectomy specimen indicated the transformation of a low-grade leukemia to a high-grade lymphoma. The overexpression of p53 in the lymph node implies that p53 mutation was probably involved in the pathogenesis of HCL transformation.     

Evaluation of Leu-M5 (CD11c) in hairy cell leukemia by the alkaline phosphatase anti-alkaline phosphatase technique

The concomitant presence of B antigens and of the antigen recognized by the monoclonal antibody Leu-M5 (CD11c) on neoplastic lymphoid cells has been reported to be largely restricted to hairy cell leukemia (HCL). The authors studied Leu-M5 reactivity of neoplastic cells from 59 patients whose specimens were referred with a stated diagnosis of HCL by using the alkaline phosphatase anti-alkaline phosphatase technique on peripheral blood (PB) and bone marrow (BM) specimens. Tartrate-resistant acid phosphatase (AcP-T) activity was also studied. In 49 patients, HCL had been confirmed previously by BM biopsy, and specimens were evaluated for disease status during or after therapy with interferon (IFN) or 2'-deoxycoformycin. The remaining ten patients were newly referred for confirmation of the diagnosis of HCL before therapy. In all 55 patients in whom the BM biopsy demonstrated HCL, virtually every leukemic cell was Leu-M5 reactive, and the reaction proved, in some cases, to be helpful in the detection of small numbers of hairy cells in PB or BM preparations. AcP-T reactivity was demonstrated in the neoplastic cells of 52 of these 55 patients, including all but 3 of those receiving IFN, and was helpful in confirming persistent leukemia when interpretation of BM biopsy sections was difficult because the numbers of hairy cells were small. However, in four of the ten newly referred patients, BM biopsy showed features of splenic lymphoma with villous lymphocytes, rather than HCL. The neoplastic cells of these four patients were of B-cell origin and in three were Leu-M5 reactive. The authors' study indicates that Leu-M5 is present in nearly all hairy cells, but its presence in conjunction with other B-cell markers is not specific for HCL.     

Specific skin lesions as the presenting symptom of hairy cell leukemia

A 68-year-old Japanese man with a chief complaint of eczema-like dermatosis was diagnosed as having B-cell hairy cell leukemia (HCL) by demonstration of hairy cells in the skin lesions as well as in blood and bone marrow. He was treated with alpha-interferon, resulting in disappearance of skin lesions and reduction of his massive splenomegaly from 18 to 5 cm in about 14 months. Although specific skin lesions in HCL, shown by a review of the literature to occur in about 8% of cases, are not as uncommon as generally assumed, it is rare for HCL to present with specific skin lesions, the present case being only the second of its type mentioned in the literature.     

Antigenic phenotypes of hairy cell leukemia and monocytoid B-cell lymphoma: an immunohistochemical evaluation of 66 cases.

Using a large panel of antibodies on multi-tumor block sections of routinely processed, paraffin-embedded fixed tissue, we compared the antigenic phenotype of 42 clinically, morphologically, and immunologically well-characterized cases of hairy cell leukemia (HCL) with 24 cases of monocytoid B-cell lymphoma (MBCL) selected from the Monocytoid B-Cell Lymphoma Registry at the City of Hope National Medical Center. The predominant antigenic phenotype of hairy cells was CD45 (leukocyte common antigen)+, CD45Ra (4KB5, MB1, MT2)+, L26+, CDw75 (LN1)+, CD74 (LN2)+, LN3+, MB2+, CD45RO (UCHL1)-, MT1-, CD15 (Leu-M1)-, neuron-specific enolase (NSE)-, epithelial membrane antigen-, and CD30 (Ber-H2)-. The immunophenotype of neoplastic monocytoid B lymphocytes was essentially identical to that of the hairy cells, with one exception: the neoplastic monocytoid B lymphocytes were stained by epithelial membrane antigen in seven cases. An interesting observation was the staining by anti-muscle-specific actin of the neoplastic cells of MBCL in 53% of cases, but of none of the cases of HCL. The results of our study (1) indicate that HCL and MBCL can be immunophenotyped reliably on fixed tissue samples, (2) further confirm the proposed lineage relationship between these two lymphoproliferative disorders, and (3) indicate that decalcification of bone marrow biopsies does not adversely affect the immunoreactivity of hematopoietic-associated antigens.     

Hairy cell leukemia and anti-leukocyte common antigen

Thirty-three bone marrow biopsies from 15 patients with hairy cell leukemia (HCL) were evaluated morphologically and immunohistochemically by use of the peroxidase-antiperoxidase technique to demonstrate reactivity for leukocyte common antigen (LCA). Hairy cells in all biopsies showed a distinctive and characteristic pattern for LCA, which decorated the periphery of the cytoplasm but that left most of the cytoplasm and the nucleus unstained. Anti-LCA was particularly helpful in highlighting focal or subtle leukemic infiltrates. Hairy cells in biopsies from three patients had, on routine morphologic examination, a spindled and sarcomatoid appearance, but these too were strongly LCA positive. Treatment regimens were variable: five patients had splenectomy and received chemotherapy; five patients had splenectomy alone; and four patients had chemotherapy alone. Seven patients received interferon, and one patient received no treatment. In those six patients who had multiple biopsies as part of follow-up examinations, hairy cells as identified by anti-LCA were continuously present. Often in significant numbers, and were usually underestimated or not identified by routine examination. In those patients who received chemotherapy, qualitative alterations in the LCA reaction of hairy cells were observed.     

Spleen alterations in hairy cell leukemia: a scanning electron microscopic study

In Hairy Cell Leukemia (HCL) peripheral blood and bone marrow cells show under the scanning electron microscope (SEM) a characteristic surface with numerous ruffles and microvilli. The spleen of a patient affected by HCL was studied by SEM after fresh sectioning and routine preparation. Cells with the typical "hairy" surface were observed infiltrating the red pulp, altering the normal reticular meshwork and causing red blood cell distortion. In the sinuses, hairy cells adhered to the endothelial cells causing sinus dilatation and destruction. Aggregates of hairy cells delimiting pooled erythrocytes were also observed and may represent the "pseudosinuses" described in previous light and transmission electron microscopic studies. These preliminary findings may explain the condition of hypersplenism which characterizes HCL. In addition, SEM is proposed as a rapid and simple method to identify HCL spleen involvement.     

Rapid detection and quantitation of BRAF mutations in hairy cell leukemia using a sensitive pyrosequencing assay

BRAF protooncogene is an important mediator of cell proliferation and survival signals. BRAF p.V600E mutation was recently described as a molecular marker of hairy cell leukemia (HCL). We developed and validated a pyrosequencing-based approach that covers BRAF mutational hotspots in exons 11 (codon 468) and 15 (codons 595 to 600). The assay detects BRAF mutations at an analytical sensitivity of 5%. We screened 16 unenriched archived bone marrow aspirate samples from patients with a diagnosis of HCL (n = 12) and hairy cell leukemia-variant (HCL-v) (n = 4) using pyrosequencing. BRAF p.V600E mutation was present in all HCL cases and absent in all HCL-v. Our data support the recent finding that BRAF p.V600E mutation is universally present in HCL. Moreover, our pyrosequencing-based assay provides a convenient, rapid, sensitive, and quantitative tool for the detection of BRAF p.V600E mutations in HCL for clinical diagnostic testing.