Aggressive B-cell lymphomas with a primary bone marrow presentation

Aggressive B-cell lymphomas present as a heterogeneous spectrum of disease. A primary diagnosis in the bone marrow (BM) may be challenging in terms of diagnostic classification and clinical handling, owing to limited architectural information. Aggressive B-cell lymphomas can be subdivided into entities that typically present primarily in the BM, and cases with BM involvement in which the bulk of disease is present in other organs. One main topic at the 2018 BM workshop of the European Association of Haematopathology/Society of Hematopathology was therefore aggressive B-cell lymphomas with a primary BM presentation. The spectrum of cases submitted to this topic gave a good overview of commonly encountered problems, as well as unusual manifestations, and highlighted areas of imprecise disease definitions and diagnostic grey zones. The categories submitted to the workshop included cases of Burkitt lymphoma (BL) with unusual features, high-grade B-cell lymphomas (HG-BCLs) with and without so-called double/triple-hit, and diffuse large B-cell lymphomas (DLBCLs) with a primary BM presentation. Areas of difficulties included the morphological boundaries of HG-BCL not otherwise specified, cases with MYC and bcl-2 or bcl-6 translocations and terminal deoxynucleotidyl transferase (TdT) expression, which were categorised as B-cell lymphoblastic leukaemia/lymphoma if most cells showed TdT positivity, and the clinicopathological overlap between intravascular large B-cell lymphoma, CD5-positive DLBCL, and DLBCL with primary presentations in the BM, spleen, and liver. This review summarises our understanding of the main aggressive B-cell lymphoma categories with a common primary BM presentation and potential problem areas, and makes suggestions for the immunophenotypic and genetic work-up, illustrated by the interesting and challenging cases submitted to the workshop.     

A method for preserving monoclonal marker expression in bone marrow biopsies from haematological disorders using a glycol methacrylate cold-embedding technique

We report a simple glycol methacrylate (GMA) cold embedding technique that can be used on bone marrow biopsy core. The biopsies were fixed in cold Bouins solution, dehydrated in cold methanol followed by infiltration and embedding in cold GMA then polymerised at 4°C under vacuum. This provided an effective cooling system, which preserved a wide range of the cell antigens by preventing heat damage due to excessive rise in temperature. This might be a useful diagnostic tool for the analyses of bone morphology and immuno-histochemistry on the same section. We have described a method of bone marrow biopsy which allows us to achieve excellent antigenic preservation and high-quality observation of morphological details in relation to expression with immuno-histochemical markers.An erratum to this article can be found at     

Our approach to bone marrow biopsies in cytopenia

Unexplained cytopenia is one of the most common indications for performing trephine bone marrow (BM) biopsy (BMB). The histopathological examination in this regard must be seen in the broader context of a multimodal approach in order to reach an as entity-specific as possible diagnosis, considering medical history, physical examination, laboratory data, peripheral blood morphology, BM aspiration smear, flow cytometry results and, if indicated, cytogenetics and molecular genetics. The particular irreplaceability of the histopathological work-up and the expectations to the BMB lie especially in the detection of fibrosing and/or focal processes (e.g. localized islets of blasts) and disorders extrinsic to the BM such as e.g. metastases, thrombotic microangiopathies, granulomatous myelitides etc. We propose a systematic combined histopathological pattern-based and blood count-based approach that can be applied in such circumstances to achieve a precise diagnosis or, at least, a clinically useful differential diagnosis, particularly taking into consideration specific morphologic pitfalls and application of ancillary techniques. Constitutional BM failure syndromes will not be profoundly addressed.     

Ancillary techniques in bone marrow pathology: molecular diagnostics on bone marrow trephine biopsies

Pathologic examination of trephine bone marrow (BM) biopsies plays a central role in the diagnosis and staging of haematological neoplasms and other disorders affecting haematopoiesis. Haematopathology has been profoundly influenced by the advent of molecular genetic techniques suitable for paraffin-embedded tissues, and certain applications, such as the determination of B- and T-cell clonality, belong to its standard diagnostic repertoire. Many of these molecular tests can be performed successfully with nucleic acids extracted from BM trephine biopsies, if some technical aspects specific to this template source such as various fixation and decalcification procedures are taken into consideration. The current indications for molecular BM diagnostics range from the confirmation of lymphoma involvement with gene rearrangement analysis, demonstration of tumor-specific translocations in lymphoid and chronic myeloproliferative disorders along to the detection of microorganisms or marrow involvement by soft tissue sarcomas. The availability of quantitative polymerase chain reaction techniques for the investigation of allelic imbalances and gene expression levels in paraffin-embedded material also open new avenues for research and advanced diagnostics. The molecular detection of minimal residual disease in haematological neoplasms, especially in the context of new treatment strategies, will provide future challenges. This article summarizes the current state of the art in molecular diagnostics applied to paraffin-embedded BM biopsies.     

Marginal zone and mantle cell lymphomas: assessment of cytomorphology in subtyping small B-cell lymphomas

The diagnosis of malignant lymphomas by fine-needle aspiration biopsy (FNAB) is increasing in utilization. The cytomorphologic distinction among the small B-cell lymphomas may be quite difficult. We are unaware of anyone who has compared directly mantle cell lymphoma (MCL) and marginal zone lymphoma (MZL) in FNAB. Our major goal was to examine the cytomorphologic attributes of MCL and MZL and to look for features distinctive of or suggestive of either neoplasm. Seven immunophenotypic MCL and seven immunophenotypic MZL aspirates were evaluated for a number of cytomorphologic features in direct smears. Features favoring MCL include a relatively monomorphic cellular population, prominent nuclear membrane contour irregularities, and mitotic figures. Conversely, a polymorphic cellular population suggested MZL. However, due to extensive overlap of specific cytologic features, the two lymphomas cannot be definitively distinguished based solely on cytomorphology. Although there are cytomorphologic attributes suggestive of either MCL or MZL, considerable overlap exists. Based on an individual case basis, the distinction cannot be made reliably by morphology alone; ancillary studies, e.g., immunophenotyping, are essential.     

Clinical utility of bone marrow flow cytometry in B-cell non-Hodgkin lymphomas (B-NHL)

AIM: To determine the efficacy of flow cytometry (FC) in the assessment of bone marrow (BM) in B-cell non-Hodgkin lymphoma (B-NHL). FC is a common practice, but is far from being validated. METHODS AND RESULTS: Morphological analysis and FC immunophenotyping were performed on 421 samples. T-cell lymphomas, Hodgkin's disease, chronic lymphocytic leukaemia and hairy cell leukaemia were not included in the study. Clonality was assessed by the standard kappa/lambda/CD19 test. Aberrant immunophenotypes present in the B-cell subpopulation were also investigated. A double-step procedure was employed in all cases to increase the sensitivity of the FC procedure. Of 380 evaluable samples, 188 corresponded to follicular lymphoma (FL), 58 to diffuse large B-cell lymphoma (DLBCL), 57 to mantle cell lymphoma (MCL), seven to Burkitt's lymphoma and the remaining 70 samples to other low-grade lymphomas. Morphological marrow infiltration was found in 148 cases, and flow immunophenotyping identified 138 cases with BM involvement. A concordance between the two methods was detected in 298 cases (79%). There was a discordance in 82 cases (21%): morphology positive/FC negative in 46 cases and morphology negative/FC positive in 36 (61% of all cases with discordance were from FL). There was no difference in outcome when patients with discordances were compared with patients without discordances. CONCLUSIONS: Most samples showed concordance between morphological and FC results. FC identified BM involvement in the absence of morphological infiltration. Morphology/FC discordance seems to have no influence on the outcome of FL patients.     

Macrophages and their subpopulations following allogeneic bone marrow transplantation for chronic myeloid leukaemia

A morphometric and immunohistochemical study was performed on 354 bone marrow trephine biopsies derived from 126 patients with chronic myeloid leukaemia (CML) before and after allogeneic bone marrow transplantation (BMT). The purpose of this investigation was to evaluate the macrophage population, including several subsets and their dynamics in the posttransplant period. In addition to the total CD68⁺ resident (mature) macrophages the so-called activated fraction identified by its capacity to express α-d-galactosyl residues, the pseudo-Gaucher cells (PGCs) and the iron-laden histiocytic reticular cells were also considered. Following immuno- and lectin-histochemical staining morphometric analysis was carried out on sequential postgraft bone marrow specimens at standardized intervals. Compared to the normal bone marrow and calculated per haematopoiesis (cellularity) an overall decrease of about 40–50% in the quantity of CD68⁺ macrophages and the BSA-I⁺ subpopulation was detectable in the early posttransplant period (9–45 days after BMT). Noteworthy was the temporal recurrence of PGCs in the engrafted bone marrow, which was not associated with a clonally transformed cell population or leukaemic relapse. Reappearance of postgraft PGCs was most prominent in the first 2 months after BMT. This conspicuous feature was presumed to be functionally associated with a pronounced degradation of cell debris following pretransplant myelo-ablative therapy (scavenger macrophages). Evidence for an activation of the BSA-I⁺ macrophage subset was derived from the identical carbohydrate-binding capacity shown by the PGCs. In the regenerating haematopoiesis shortly after BMT a significant correlation between the number of BSA-I⁺ macrophages and erythroid precursor cells was determinable. This result implicates a close functional relationship between postgraft reconstitution of erythropoietic islets and centrally localized activated macrophages. In conclusion, findings emerging from this study included the reappearance of PCGs in the engrafted bone marrow independently of a leukaemic relapse and the significant association of the activated BSA-I⁺ macrophage subset with the recovery of erythropoiesis. Received: 31 January 2000 / Accepted: 6 March 2000     

Recommendations for the biopsy procedure and assessment of skeletal muscle biopsies

 Muscle biopsy has a valuable diagnostic role in many neuromuscular diseases, but it is an invasive investigation that should not be undertaken lightly. Furthermore, the biopsy procedure and subsequent laboratory processing of the specimen may significantly influence the results. The following guide is designed to optimise the diagnostic information that can be obtained from muscle biopsy. It covers the whole procedure, from selection of the biopsy site and technique of biopsy, progressing through freezing of the specimen for histochemistry, and the role of immunocytochemistry and electron microscopy. Finally, the contents of a model biopsy report are considered. Received: 7 April 1997 / Accepted: 7 April 1997     

Osteomyelofibrosis/-sclerosis: A histological and cytogenetic study on core biopsies of the bone marrow

Summary A combined histological and cytogenetic study was performed on the bone marrow in 33 patients with overt osteomyelofibrosis/-sclerosis (MF/OMS) and so called agnogenic myeloid metaplasia including blast crisis. Histopathology of the plastic embedded samples of bone marrow showed an abnormal proliferation of megakaryopoiesis with conspicuous atypias of growth and maturation in addition to a neoplastic neutrophilic granulopoiesis, particularly in the early stages of MF. Thus a biphasic population of neoplastic hematopoiesis is postulated and this lesion is called chronic megakaryocytic-granulocytic myelosis (CMGM) with myelofibrosis — CMGM stage III — or with osteomyelosclerosis — CMGM stage IV. Initiation of fibrillogenesis, the most striking alteration of this disorder, is partially attributed to disorganization of megakaryopoiesis with abnormal proliferation and clustering around the sinuses and intraluminal growth, with subsequent obliteration of the vascular compartment. Cytogenetic evaluation demonstrated the Philadelphia chromosome (Ph'-chromosome) in 93% of CGL and in 67% of MF/OMS, including cases with blast crisis. Unlike CGL and MF/OMS where a Ph'-chromosome is common, myelofibrosis of non-neoplastic origin and AML displayed no Ph'-chromosome. Further aberrations such as aneuploidy involved the C/D group chromosomes predominantly and were especially prominent in blast crisis (about 50%) with no significant differences in CGL and MF/OMS or in AML. Our results of chromosomal analysis, evaluated in close context with histopathology, show no fundamental differences between CGL and myeloproliferative disorders of mixed cellularity, i.e., chronic megakaryocytic-granulocytic myelosis (CMGM). For this reason the terminal stages of fibrotic and osteosclerotic lesions belong into these categories of CMGM or CGL respectively. In conclusion MF/OMS are final stages or subtypes of CML, carrying the same chromosomal marker and demonstrating remarkable atypias of the hematopoietic tissue suggestive of malignancy. The fibrotic/ osteosclerotic alteration itself is thought to represent a secondary nonneoplastic feature.Supported by the Deutsche Forschungsgemeinschaft (grant GE 121/20)     

Immunophenotype of hairy-cell leukaemia after cold polymerization of methyl-methacrylate embeddings from 50 diagnostic bone marrow biopsies

Hairy-cell leukaemia may be difficult to diagnose in bone marrow biopsies, especially in the early stages or in its residum after complete clinical remission. To consider the impact of published data on immunophenotyping hairy-cell leukaemias, a total of 50 diagnostic biopsies were systematically analysed with a panel of eight antibodies and compared with cases of chronic lymphatic leukaemia (CLL), 20 follicular centre lymphomas, 20 lympho-plasmacytoid immunocytomas, 10 small-cell T-cell non-Hodgkin lymphomas and 20 cases of benign nodular lymphatic hyperplasia. The panel of eight antibodies comprised DBA44, CD45, CD20, CD45R, CD45R0, CD43 and the CD68 antibodies KP1 and Ki-M1P. The hairy-cell leukaemias were staged histologically into four categories of bone marrow infiltration. DBA44 reacted positively in 47/50 cases. CD45 and the B-cell markers CD20 and CD45R reacted in 49/50 and 43/50 cases, respectively. One CD68 marker, KP1, was positive in 38/50 cases but the other — Ki-M1P — only in 1/50 cases. Chronic lymphatic leukaemia cases, the other B-cell NHLs and lymphatic hyperplasias showed strong positivity for CD20 and CD45R, but only the immunocytomas reacted with DBA44 in 7/20 cases. The T-cell NHLs and hyperplasias showed a strong positivity for the T-cell markers CD45R0 and CD43. The CD68-marker Ki-M1P revealed a high specificity, since it was negative in all NHLs and positive only in one hairy-cell leukaemia. Methyl-methacrylate embedding of bone marrow biopsies under cold polymerization produces a high quality of histo- and cytomorphology, resulting in greater diagnostic reliability and the detection of low-stage infiltration of hairy-cell leukaemia. DBA44 appears as a highly specific antibody to mark hairy-cells since only immunocytomas reacted positively in a few cases. A small panel of antibodies including DBA44, CD20, CD45R and Ki-M1P may serve to distinguish small-cell NHL from hairy-cell leukaemia even at an early stage or when there are minimal residual tumour cells.     

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。     

4248例骨髓活检组织病理的初步分析

对４２４８例骨髓活检组织的病理变化进行分析，结果显示：骨髓活检对许多血液疾病的诊断、预后、分类、分期有一定价值，对早期白血病、慢粒急变，活检可发现先于涂片的变化。分析结果与表明活检对于骨髓纤维化入恶性肿瘤转移等的诊断有较大的作用。并讨论了活检和涂片的优点和不足，指出对有些疾病的诊断，如淋巴瘤、白血病的分类等，两者结合起来分析。     

Enzyme and immunohistochemistry on undecalcified bone and bone marrow biopsies after embedding in plastic: A new embedding method for routine application

Summary A simplified method of low temperature methyl and butyl methacrylate embedding (up –20° to –15° C) is demonstrated using a proper redox system of benzoyl peroxide and aromatic amine. This method combines the morphological superiority of plastic-embedded bone tissue and bone marrow sections with the advantages of specific enzyme histochemical and immunochemical markers. The method permits good preservation of morphological details, the survival of antigenic determinants and the retention of enzyme activities. The specimens were fixed in 1.6% formaldehyde and 5% sucrose in 0.02 M phosphate buffer at pH 7.4, washed in 0.02 M phosphate buffer and 5% sucrose, dehydrated with acetone and impregnated with monomers of embedding medium. All these steps were carried out at +4° C. The method presented is especially suitable for enzyme histological and immunohistological diagnosis of primary and secondary bone tumours, soft tissue tumours, as well as myelo- and lymphoproliferative disorders of bone marrow biopsies. Examples are demonstrated with mono- and polyclonal antibodies and reaction products of hydrolytic enzymes.Dedicated to Prof. Dr. Gerhard Seifert on the occasion of his 70th birthday     

Intravascular large B-cell lymphoma with bone marrow involvement at presentation and haemophagocytic syndrome: two Western cases in favour of a specific variant

AIMS: To report two cases of an unusual form of intravascular lymphoma, characterized by bone marrow involvement at presentation with haemophagocytic syndrome. METHODS AND RESULTS: We describe the clinicopathological features of two patients with intravascular lymphoma primarily involving bone marrow. Both patients complained only of fever with pancytopenia and reactive haemophagocytic syndrome. Diagnosis was made on bone marrow examination, which showed large tumour cells of B-cell lineage confined within the lumen of sinuses. CONCLUSION: These two cases and five previous reports could represent a variant of intravascular lymphoma, characterized by early involvement of bone marrow without dissemination to other organs. This form of intravascular lymphoma, called IVL-HS, seems to be an 'Asian' variant with a high prevalence in Asian people and a very low prevalence in Western countries. At a practical level, bone marrow biopsy may be useful in the diagnosis of intravascular lymphoma when the clinical presentation is restricted to fever of unknown origin with a reactive haemophagocytic syndrome.     

Clinical role of flow cytometry in redefining bone marrow involvement in diffuse large B-cell lymphoma (DLBCL) - a new perspective

Aims:  The clinical role of flow cytometry in staging bone marrow in diffuse large B-cell lymphoma (DLBCL), especially its impact on outcome, remains uncertain. The aim was to determine the contribution of flow cytometry to conventional staging, and to study the impact of this revised staging on survival.
Methods and results:  One hundred and thirteen cases of DLBCL diagnosed at The Canberra Hospital from 1996 to 2005 were identified. Blinded analysis of bone marrow (BM) morphology and flow cytometric data showed involvement on morphology (M) in 25 (22.1%) cases, on flow cytometry (F) in 21 (18.6%) cases and overall (M + F) in 32 cases (28.3%); discordance was noted in 16 cases (16.1%). Cases with and without marrow involvement on conventional staging alone (M) had no significant difference in survival ( P  = NS). However, when BM involvement was defined as positivity on morphology and/or flow cytometry (M + F), the median survival of patients with involvement was significantly worse than patients without involvement ( P  = 0.026).
Conclusions:  Flow cytometry-positive cases should be included with those positive on morphology in a summative model to define BM involvement in DLBCL, as it may have a potential impact on predicting outcome.     

Broncho-bronchiolitis obliterans as a complication of bone marrow transplantation: a clinicopathological study of eight autopsy cases

 We identified eight patients with bronchiolitis obliterans (BO) in the autopsies of 81 bone marrow transplant (BMT) recipients. Rapidly progressive dyspnoea and cough were the main presenting symptoms in all eight patients, associated with overinflation and/or infiltrative opacity seen on chest X-ray and obstructive disorder revealed by pulmonary function tests. Early lesions were characterized by epithelial loss and an inflammatory infiltrate containing foamy histiocytes with mild luminal narrowing. Partial or total occlusion of the bronchiolar lumina by fibrous connective tissue was the feature of late lesions. Both changes were coexistent in all cases. In one case, small bronchi with cartilage were also affected by the obstructive process, showing bronchitis obliterans. All eight patients showed non-obstructive broncho-bronchiolitis characterized by denuding of respiratory epithelium, mural oedema and an inflammatory infiltrate in addition to BO, and these changes were also seen in 18 patients without BO. The submucosal glands of large bronchi and the trachea showed mucous retention and a mild inflammatory infiltrate in four of the eight patients. Coexistent infectious processes were seen in all cases, cytomegalovirus and Aspergillus being the most frequent organisms. BO probably develops as an immunopathological event related to graft-versus-host disease (GVHD) during the impaired immune status phase of the post-BMT period, possibly initiated by infection. Bronchial gland involvement in chronic GVHD is one of the factors responsible for this abnormal immune status. Received: 14 January 1997 / Accepted: 5 March 1997