Magnetic resonance imaging of bone marrow versus bone marrow biopsy in malignant lymphoma

Bone marrow involvement is a frequent finding in malignant lymphoma. Bone marrow biopsy of the posterior iliac crest is routinely performed for staging. Abnormal magnetic resonance imaging (MRI) signals of bone marrow was also reported to be indicative of bone marrow involvement. This study included 60 patients with malignant lymphoma. Unilateral bone marrow biopsy of the posterior iliac crest was performed. MRI of lumbar spine was studied within 24 hours of bone marrow biopsy. 22 healthy controls were used for the detection of MRI objectivity during visual evaluation. In 83% of patients (50/60), biopsy and MRI results agreed completely. In two patients, histologic sections failed to show any evidence of bone marrow involvement despite abnormal MRI signals suggestive of involvement. In three patients, MRI was completely normal despite biopsy proven bone marrow infiltration. False negativity (3/60) and false positivity (2/60) rates were very low. Negative biopsy findings with positive or equivocal MRI results should not exclude bone marrow involvement and needs further evaluation with bilateral or guided biopsy. Thus, we conclude that MRI of bone marrow is a fairly sensitive, noninvasive modality and might be of potential value in detecting bone marrow infiltration in malignant lymphoid neoplasms which can be utilized as a useful adjunct to standard staging procedures.     

Cell Suspensions from Collagenase Digestion of Bone Marrow Trephine Biopsy Specimens—its Use in Lymphoma

Collagenase digestion allows cells to be released into suspension from bone marrow tissue. Discrete abnormal populations of lymphoid cells can be identified by cell morphology and immunological phenotyping techniques. Viable cells are also available for chromosomal analysis. This technique makes cells available for analysis in cases of dry bone marrow taps and has a particular use in the investigation of bone marrow involvement by malignant lymphoma.     

Femoral marrow MRI is a non-invasive,non-irradiated and useful tool for detecting bone marrow involvement in non-Hodgkin lymphoma

Femoral marrow magnetic resonance imaging (MRI) is a non-invasive, non-irradiated and useful modality for evaluating bone marrow (BM) conditions. Human adult femoral BM is almost uniformly fatty marrow and has the largest volume of a single bone. MRI has an extremely high resolution for fat and water, which allows high-contrast imaging of cellular infiltration into fat tissue. In hematological diseases, femoral BM MRI can clearly detect cell infiltration, which is symmetrically imaged from the proximal to the distal direction of abnormal signal areas. Thus, we investigated the significance of femoral MRI for non-Hodgkin lymphoma (NHL). We analyzed the data of 69 NHL patients who received femoral MRI at diagnosis in this single-center retrospective cohort study. The median patient age was 73 years. MRI patterns were mainly classified as uniform patterns or nonuniform patterns. We also classified the range of cellular marrow as high-grade or low-grade based on whether it had spread to over half of the femur. Both overall survival (OS) and progression-free survival (PFS) were significantly influenced by abnormal femoral marrow MRI. In particular, the patients with cellular femoral marrow lesions had a worse OS and PFS based on log-rank tests. Multivariable analyses with the Cox proportional hazards model revealed that OS and PFS were significantly influenced by cellular marrow diagnosed by femoral MRI. We concluded that femoral marrow MRI is a useful tool for detecting BM involvement and an independent prognostic factor in NHL patients.     

Bone Marrow Transplantation in Low-Grade Non-Hodgkin's Lymphoma

The low-grade histologic types constitute one quarter of all non-Hodgkin's lymphomas (NHL). Conventional chemotherapy and chemo-radiation therapy have failed to significantly alter the course of this disease, and most patients eventually succumb to lymphoma. Despite the fact that NHLs exhibit a steep dose-response relation to cytotoxic therapy, fewer than 30% of eligible patients undergo bone marrow transplantation. Reasons for fewer patients receiving this course of treatment include: elderly patient population, extensive previous chemotherapy and/or radiation therapy, high incidence of bone marrow involvement, and transformation to higher grade NHLs. In recent years, improvements in several areas have enhanced the therapeutic index for bone marrow transplantation. These advances include the use of more effective preparative regimens, recombinant hematopoietic growth factors, extended-spectrum antibiotics, and an increased expertise in blood transfusion techniques and practices. Other, more effective strategies include sophisticated in vitro bone marrow purging approaches and peripheral blood progenitor cell collection. As a result, more patients have been able to receive dose-intensive therapy followed by hematopoietic cellular rescue. Although follow up is short in most series, encouraging results have stimulated some centers to begin transplanting responding patients earlier in their disease course; in more than 200 patients treated in this fashion, long-term disease-free survival has been achieved in nearly 70% of patients, some patients for a period of greater than 6 years. The new purine analogues fludarabine, pentostatin, and 2-chlorodeoxyadenosine also have shown promise in both initial and salvage treatment of low-grade NHLs. It remains to be determined whether this group of drugs will be complimentary to the bone marrow and/or peripheral blood progenitor cell transplant approach.     

非霍奇金淋巴瘤侵犯骨髓的病理形态及免疫表型特点分析

目的:探讨非霍奇金淋巴瘤(NHL)侵犯骨髓的病理形态、免疫表型特点.方法:对骨髓活检标本,石蜡包埋切片,HE染色,光镜观察形态免疫组化进行表型分析.结果:65例中,B细胞淋巴瘤39例,T细胞淋巴瘤26例.形态学上,B细胞淋巴瘤多以混合型、弥漫型侵犯为主,外周T细胞淋巴瘤(PTCL)以间质型、混合型侵犯多见,伴有浆细胞、嗜酸细胞等反应性成分.毛细胞白血病(HCL)呈蜂窝样外观,具有诊断特异性.26例有髓外原发淋巴瘤者,瘤细胞形态与相应骨髓活检形态一致.免疫组化可对大部分淋巴瘤分型.6例小B细胞淋巴瘤不能分型的,2例结合脾脏病理特点确诊,4例仅有骨髓活检标本的,有待进一步检查确定.结论:多数NHL骨髓侵犯具有明确的形态学及免疫表型特点,可以诊断并分型.少数需结合原发部位及其它检查确诊.     

Primary bone marrow lymphoma is a rare neoplasm with poor outcome: case series from single tertiary care centre and review of literature

Primary bone marrow lymphoma is a rare disease and remains undiagnosed due to deceptive clinical presentation. Here, we report four cases of primary bone marrow B‐cell non‐Hodgkin lymphoma, which presented with cytopenias without any lymphadenopathy or organomegaly. Bone marrow examination revealed large atypical B‐cells with a reactive T‐cell infiltrate with suppression of the normal hematopoietic elements. This lymphoma is known to have a poor prognosis. Inspite of treatment, two of our patients died during chemotherapy. Two patients relapsed, of which one showed an early relapse after two months and was put on an alternative regimen. The other patient relapsed twice at an interval of 4 and 5 years, respectively, following which he remained in remission for another 5 years and had recently shown a relapse for the third time. Review of literature revealed seven case series and 11 case reports of primary bone marrow lymphoma in the last five decades.     

The value of bone marrow biopsy for staging of patients with primary CNS lymphoma

BackgroundIn patients with presumed primary CNS lymphoma (PCNSL), a systemic manifestation is found only in a small minority. Although bone marrow biopsy (BMB) is recommended for staging, its diagnostic value is unclear.MethodsA retrospective analysis of 392 patients with presumed PCNSL from 3 university hospitals and 33 patients with secondary CNS lymphoma (SCNSL) and initial CNS involvement from a multicenter Germany-wide prospective registry was performed.ResultsA BMB was performed and documented in 320/392 patients with presumed PCNSL; 23 had pathologic results. One harbored the same lymphoma in the brain and bone marrow (BM), 22 showed findings in BM discordant to the histology of brain lymphoma; n = 12 harbored a low-grade lymphoma in the BM, the other showed B-cell proliferation but no proof of lymphoma (n = 5), monoclonal B cells (n = 3), or abnormalities not B-cell-associated (n = 2). In the group of SCNSL with initial CNS manifestation, 32/33 patients underwent BMB; 7 were documented with bone marrow involvement (BMI); 1 had concordant results in the brain and BM with no other systemic manifestation. Six had additional systemic lymphoma manifestations apart from the brain and BM.ConclusionsIn only 2 out of 352 (0.6%) patients with CNS lymphoma (320 presumed PCNSL and 32 SCNSL), BMB had an impact on diagnosis and treatment. While collected in a selected cohort, these findings challenge the value of BMB as part of routine staging in presumed PCNSL.     

评价全身FDG-PET/CT在诊断淋巴瘤患者骨髓浸润中的价值

目的:本研究旨在评价PET-CT和骨髓涂片、骨髓活检、免疫分型结果诊断淋巴瘤的一致性和相关性。方法:收集临床确诊淋巴瘤患者的详细临床信息,包括姓名、性别、年龄、淋巴瘤细胞起源、病理分型、临床分期、行为状态、有无B症状、血LDH水平、血β2微球蛋白水平、骨髓涂片结果、免疫分型结果、骨髓活检结果以及详细的PET-CT影像学描述等。根据不同临床信息为患者进行详细分层,评价影响PET-CT中骨髓摄取葡萄糖的因素、影响淋巴瘤骨髓浸润的因素。设定骨髓涂片、骨髓活检、免疫分型阳性为对照,探究PET-CT在诊断淋巴瘤患者骨髓浸润中的价值。分别探讨PET-CT对于诊断不同病理类型淋巴瘤患者骨髓浸润的差异。结果:在性别、病理类型、细胞起源、有无B症状及骨髓浸润等不同分层中,只有淋巴瘤骨髓浸润与PET-CT中骨髓葡萄糖摄取有密切相关性(P=0.002)。而骨髓浸润与年龄(P=0.017)密切相关。设定骨髓涂片、骨髓活检、免疫分型阳性为对照,PET-CT检测淋巴瘤总体骨髓浸润的敏感度为54.3％、特异度为80.5％、准确度为74.5％,并且在不同病理类型中差异显著。PET-CT可以与骨髓涂片、骨髓活检、免疫分型共同指导淋巴瘤临床分期。结论:PET-CT中的骨髓葡萄糖摄取对淋巴瘤骨髓浸润及临床分期有一定的指导意义。不同病理类型的淋巴瘤中,PET-CT与骨髓涂片、骨髓活检、免疫分型的一致性不尽相同。PET仍不能完全取代骨髓涂片、骨髓活检、免疫分型。     

Optimum trephine length in the assessment of bone marrow involvement in patients with diffuse large cell lymphoma.

BACKGROUND: The National Cancer Institute has recommended a bone marrow biopsy length of >/=20 mm for the staging and surveillance of patients with non-Hodgkin's lymphoma. However, there are few published data to support this recommendation, particularly the role of examining multiple levels. PATIENTS AND METHODS: Bone marrow biopsies from 172 patients with newly diagnosed diffuse large cell lymphoma (DLCL) entered in two consecutive trials of the Australasian Leukaemia and Lymphoma Group were analysed. The original haematoxylin and eosin-stained trephine biopsy and two or more deeper sections cut at 0.1-0.2 mm intervals were assessed with respect to the morphology, extent and pattern of lymphomatous involvement. The rate of positive diagnosis was correlated with the length of the biopsy specimen and the number of sections examined. RESULTS: Forty-seven biopsies (27%) demonstrated marrow involvement on examination of a mean of four trephine biopsy sections. The rate of positivity increased with the examination of multiple levels and correlated with increasing trephine length but was not dependent on the number of sites sampled. Twenty per cent of biopsies <20 mm in length were positive for lymphoma; this increased to 35% for biopsies >/=20 mm (P = 0.023). CONCLUSIONS: Morphological bone marrow involvement in DLCL is optimally demonstrated by a 20-mm long trephine biopsy from a single site which is examined at multiple levels (four or more). This obviates the need for bilateral sampling, thereby reducing patient morbidity from the procedure. This study provides evidence to support the National Cancer Institute recommendations regarding trephine biopsy in the staging of DLCL, providing multiple levels are examined.     

Outcome of Patients with Relapsed or Refractory Non-Hodgkin's Lymphoma Referred for Autologous Bone Marrow Transplantation

Fifty-one patients with relapsed or refractory intermediate- or high-grade non-Hodgkin's lymphoma were referred for autologous bone marrow transplantation (ABMT). The primary criterion for eligibility was sensitivity to conventional-dose salvage chemotherapy. Of 47 patients who received salvage chemotherapy, 30 demonstrated chemotherapy-sensitive disease. Six eligible patients did not undergo ABMT for various reasons. A total of 24 patients underwent ABMT, with etoposide, melphalan ± total body irradiation as the intensive therapy regimen. There was one early treatment-related death and three non-responders. Of the remaining patients, 9 relapsed, while 11 remain in continuous complete remission (CR) at a median follow-up of 21 months after transplant (range 5-37 months). Two patients with chemosensitive disease and bone marrow involvement underwent allogeneic BMT with marrow from HLA-identical siblings. Both are in continuous CR at 6 and 12 months follow-up. Of the 25 patients who did not undergo ABMT, all have died (median survival 5 months).

The results indicate that approximately one-half of relapsed or refractory aggressive histology lymphoma patients referred for ABMT eventually undergo transplantation, if chemotherapy-sensitive relapse is the major criterion for eligibility. Approximately 25% of the referred patients may become long-term disease-free survivors with this approach. Reports of marrow transplant series should include all patients referred for ABMT as the denominator for calculating disease-free survival in order to reduce the bias of patient selection.     

恶性淋巴瘤骨髓侵犯相关因素分析

目的 探讨恶性淋巴瘤骨髓侵犯的相关因素。方法分析恶性淋巴瘤骨髓侵犯57例初治患者的临床资料。结果恶性淋巴瘤骨髓侵犯与患者的年龄、病理类型、临床分期、受累部位、有无全身症状、病程等有关，年龄以30岁以下为多(50％)，病理类型以小淋巴细胞型及弥漫型裂细胞、淋巴母细胞、大细胞多见(84％)，临床分期以Ⅲ期、Ⅳ期为多(95％)，受累部位以纵隔及脾脏为多(44％、32％)，有全身症状者占63％，平均病程4．5月，45例NHL骨髓侵犯(BMI)患者仅有3例外周血象异常。结论恶性淋巴瘤患者年轻、病理类型差、临床分期晚、纵隔及脾脏受累、有全身症状、病程长者易出现骨髓侵犯，但BMI患者外周血象不能提示骨髓侵犯。为正确分期和指导临床治疗，应常规行骨髓涂片检查。     

骨髓涂片、骨髓活检对弥漫性大B细胞淋巴瘤临床分期的价值

目的:探讨骨髓涂片、骨髓活检对弥漫性大B细胞淋巴瘤(DLBCL)临床分期的价值.方法:对44例累及骨髓的病例回顾性分析骨髓涂片及骨髓活检切片,分别比较细胞学形态、组织形态、增生程度、纤维组织增生程度、检出率和敏感性.结果:骨髓涂片中可见中到大型的异型细胞骨髓,切片中瘤细胞以灶型最常见.按Manoharm改良法评估,骨髓切片中网状纤维含量有不同程度增多.骨髓涂片与骨髓切片增生程度的比较,差异有统计学意义(P＜0.05),切片组增生程度高于涂片组.骨髓涂片与骨髓切片检出率的比较,差异有统计学意义(P＜0.05),切片组检出率高于涂片组.骨髓涂片与骨髓切片敏感性的比较,差异有显著统计学意义(P＜0.01),切片组敏感性明显高于涂片组.结论:骨髓涂片简单易行,骨髓切片在骨髓组织状况、优势增生细胞等方面有优势,同时开展涂片和切片的检测,提高检出率,可以修正临床分期,如能同时进行流式细胞免疫表型分析,则更能提高检出率.     

Entourage: the immune microenvironment following follicular lymphoma

In follicular lymphoma, nonmalignant immune cells are important. Follicular lymphoma depends on CD4+ cells, but CD8+ cells counteract it. We hypothesized that the presence of follicular lymphoma is associated with higher CD4+ than CD8+ cell numbers in the tumor microenvironment but not in the immune system. Using flow cytometry, pre-treatment and follow-up CD4/CD8 ratios were estimated in the bone marrow, blood and lymph nodes of untreated follicular lymphoma patients in two independent data sets (N(1)=121; N(2)=166). The ratios were analyzed for their relation with bone marrow lymphoma involvement. Bone marrows were also investigated with immunohistochemistry. In either data set, the bone marrow CD4/CD8 ratios were higher in bone marrows involved with lymphoma (P=0.043 and 0.0002, respectively). The mean CD4/CD8 ratio was 1.0 in uninvolved and 1.4 in involved bone marrows. Also higher in involved bone marrows were CD4/CD56 and CD3CD25/CD3 ratios. No blood or lymph node ratios differed between bone marrow-negative and -positive patients. Sequential samples showed increased bone marrow CD4/CD8 ratios in all cases of progression to bone marrow involvement. Immunohistochemistry showed CD4+, CD57+, programmed death-1+, forkhead box protein 3+ and CD21+ cells accumulated inside the lymphoma infiltrates, whereas CD8+, CD56+ and CD68+ cells were outside the infiltrates. This study provides evidence in vivo that the microenvironment changes upon follicular lymphoma involvement.     

Prognostic Significance of Bone Marrow Trephine and Peripheral Blood Smears in 55 Patients with Mantle Cell Lymphoma

Bone marrow trephine and peripheral blood smears taken at diagnosis of 55 cases of well-documented mantle cell lymphomas were reviewed in order to analyse the leukaemic involvement in this non-Hodgkin's lymphoma: its incidence, morphological characteristics and prognostic significance. A median survival of 36 months was found. The median age was 61 and the male to female ratio was 4:1. Morphologically 7 cases presented with a mantle zone pattern, all the others had a diffuse pattern. Involvement of the bone marrow was found in 58% and a trend for prolonged survival in patients with a negative trephine was seen. An absolute lymphocytosis above 10,000 μ1 was found at diagnosis in 5 cases (10%) and had a statistically significant impact on survival. An additional 5 cases developed frank leukaemia during the course of the disease and died within 1 to 6 months of this evolution, suggesting that marked lymphocytosis is more a terminal event associated with an extremely poor prognosis than a presenting symptom. Finally we identified an additional parameter with statistically prognostic significance, namely, the presence of atypical cells in the peripheral blood even in the absence of an increased lymphocytosis.     

Magnetic Resonance Imaging in Patients with Bone Marrow Disorders

Magnetic resonance imaging (MRI) provides a non-invasive means to evaluate a large fraction of marrow in less than one hour. Marrow disorders produce non-specific changes in marrow signal intensities which primarily reflect changes in proportions of fat and cellular elements. The pattern of these signal changes narrows the differential diagnosis, and the combination of these features with the clinical context allows interpretations which are clinically useful in many ways. These include: I) the diagnosis of avascular necrosis (and its distinction from other causes of joint pain), 2) detection of osteomyelitis, 3) differential diagnosis of hypo-plastic disorders, 4) staging of lymphomas and myeloma, 5) selection of patients for autolo-gous bone marrow transplant, 6) objective measures of marrow response to therapy, 7) detection of leukemic transformation, and 8) improved detection of marrow disease (primary or secondary) in patients with otherwise unexplained bone pain.     

Bone marrow scintigraphy using Technetium-99m antigranulocyte antibody in malignant lymphomas

Background: The purpose of this study was to elucidate the clinical reliability of immunoscintigraphy (IS) to detect infiltration of the bone marrow in patients with malignant lymphoma.Patients and methods: Whole body IS was performed in 103 patients with Hodgkin's disease (HD) or non-Hodgkin's lymphoma (NHL) using Tc-99m labelled anti-NCA-95 which allows visualization of the granulopoietic bone marrow. Of these, 52% were studied prior to any therapy. Findings were compared to posterior iliac crest biopsy as well as MRI and/or follow-up examination. Criteria of marrow infiltration were a positive biopsy, positive follow-up, or positive results of MRI.Results: Comparison of IS and biopsy revealed concordant findings in 69 and discordant findings in 34 of 103 patients. Of the 34 patients with discordant results, IS showed lesions suspicious of bone marrow infiltration in 29 patients despite normal biopsy findings. When follow-up and additional examinations were taken into consideration, 10 patients remained with probably false positive and five with false negative IS findings. IS proved to be highly sensitive and specific in patients with HD (100% and 84%, respectively) and high-grade NHL (93% and 84%, respectively). Moderate sensitivity (60%) was found in low-grade NHL. This was possibly due to false negative IS in three to five patients with chemotherapy in contrast to one of five false negative results in patients without chemotherapy.Conclusion: Bone marrow scintigraphy using antigranulocyte antibodies is highly sensitive in HD and high-grade NHL. Positive findings in IS subsequent to a negative biopsy should be followed by guided re-biopsy or MRI.     

非霍奇金淋巴瘤骨髓侵犯相关血液学因素分析

目的：探讨非霍奇金淋巴瘤患者发生骨髓侵犯与相关血液学因素的关系。方法：对55例初诊的非霍奇金淋巴瘤患者进行骨髓穿刺涂片细胞学检查和骨髓活体组织检查,并检测其血常规及其他外周血相关参数的情况,分析这些参数与骨髓侵犯的相关性。结果：淋巴瘤侵犯骨髓发生率为29.09％。淋巴瘤侵犯骨髓患者的血红蛋白和血小板分别为（10967±20.90）g／L和（148.93±96.79）×10^9／L,均低于无骨髓侵犯的患者[（120.31±15.21）g／L和（293.38±138.91）×10^9／L]（P〈0.05）;前者D-二聚体和β2-MG分别为（2671.73±2443.12）ng／ml和（5.76±3.62）mg／L,均高于后者（1224.29±1063.10）ng／ml和（3.28±1.59）mg／L）]（P〈0.05）。而淋巴瘤细胞白血病患者白细胞为（11.42±9.29）×10^9／L,FIB和LDH分别为（5.90±2.61）g/L和（818.33±1011.36）U／L,均高于淋巴瘤侵犯骨髓患者的水平[（5.73±2.07）×10^9／L,（3.64±1.29）g／L,（307.64±274.08）U／L]（P〈0.05）。结论：初诊的非霍奇金淋巴瘤患者,外周血象的异常、高纤维蛋白原血症以及高水平的血清D-二聚体、LDH、β2-MG,与发生骨髓侵犯相关,及时诊断淋巴瘤侵犯骨髓和淋巴瘤细胞白血病,为NHL诊治及预后判断提供指导。     

非霍奇金淋巴瘤骨髓受累的诊断技术与预后评估

骨髓受累（bone marrow involvement, BMI）是非霍奇金淋巴瘤不良预后的标志,因其在评估预后和指导治疗中举足轻重的地位,而成为非霍奇金淋巴瘤（NHL）初诊时必备的评估内容。在其检出手段中,骨髓活检（bone marrow biopsy, BMB）具备基石的地位,但随着抽吸物的流式细胞学技术、细胞遗传学技术以及分子生物学技术等技术进步,其诊断意义也在提升,并展现出评估预后的价值。同时,PET-CT作为一种有效的检出方法,也逐渐成为研究热点。本文将综述这些检出方法,同时对BMI新近的预后研究进行回顾,以展望其研究前景。     

Immunophenotype of Bone Marrow Mast Cells in Indolent Systemic Mast Cell Disease in Adults

One of the major advances in the histological diagnosis of bone marrow (BM) involvement in mastocytosis has been the specific immunohistochemical detection of tryptase on most cells (MC), which has shown to be of great diagnostic value, especially in cases of malignant mastocytosis. On the other hand, recent studies have clearly shown that bone marrow mast cells can be specifically identified and accurately enumerated using multiparametric flow cytometry, which allow a systematic analysis of the immunophenotypic characteristics of bone marrow mast cells. Once this flow cytometric approach was applied for the analysis of BMMC from mastocytosis patients clear immunophenotypical differences were found between BMMC from normal individuals and adults with mastocytosis. The most characteristic immunophenotypic feature, both in malignant and adult indolent systemic mast cell disease, being the coexpression of CD2 and CD25 antigens, never present in normal bone marrow mast cells and, which constitute an aberrant hallmark of bone marrow mast cells in adult mastocytosis. Furthermore, bone mast cells from mastocytosis display a higher reactivity for CD35, CD63, and CD69 activation-associated antigens. Based on these results it could be concluded that the use of multiparametric flow cytometric immunophenotyping of BMMC in adult patients suffering from cutaneous mastocytosis can be of great utility for the diagnosis of BM involvement; additionally, this might also help to establish the real incidence of BM involvement in cutaneous mastocytosis.     

Salvage Therapy for Relapsed Mediastinal B-Cell Lymphoma with Allogeneic HLA-Identical Related Donor Bone Marrow Transplantation, Donor Lymphocyte Infusion and IDEC-C2B8

Primary B-cell lymphoma of the mediastinum is an aggressive non-Hodgkin's lymphoma with distinct clinicopathologic features. Response rates are between 60-80% following intensive chemotherapy regimens. Poor responders or patients with an early relapse usually do not achieve a prolonged second remission with conventional salvage therapy protocols and therefore qualify for intensive or experimental approaches. Here we describe two patients of same age, gender and stage with primary mediastinal B-cell lymphoma and an early relapse after the first courses of combination chemotherapy and irradiation of the mediastinum. One patient relapsed after a salvage therapy with allogeneic donor-related bone marrow transplantation and donor lymphocyte infusion but responded again with a continuing good partial remission after infusion of the chimeric anti-CD20 antibody IDEC-C2B8. For the other patient an allogeneic bone marrow transplantation was not possible. He finally failed to respond to salvage therapy with IDEC-C2B8 and died of progressive disease. The anti-CD20 antibody IDEC-C2B8 induced a partial remission in a patient with primary mediastinal B-cell lymphoma refractory to other therapeutic approaches, including allogeneic bone marrow transplanatation (alloBMT), donor lymphocyte infusion (DLI) and irradiation. The role of IDEC-C2B8 as a component of salvage regimens appears to be worthy for further evaluation in high-risk patients with primary mediastinal B-cell lymphoma