Bone marrow trephine biopsy in lymphoproliferative disease

Challenges Encountered and Pattern-Based Analysis of Bone Marrow Biopsy in Lymphomas: An Institutional Experience

Objective The evaluation of bone marrow (BM) status is an integral part of the initial workup of patients diagnosed with lymphoma as it plays an important role in staging and predicting prognosis in these patients. This article determines the incidence and pattern of BM involvement in lymphoma cases and distinguishes benign from malignant lymphoid aggregates in BM biopsies.

Materials and Methods The study group included 121 cases of Hodgkin and non-Hodgkin lymphomas for which BM biopsies were performed, fixed in acetic acid-zinc formalin solution, decalcified using 10% formic acid, and subjected to hematoxylin and eosin and immunohistochemistry.

Results The overall incidence of BM biopsy involvement in our study was 31.4% (37/118), including 34.7% (35/101) in cases of B cell lymphomas, 25% (2/8) in cases of T cell lymphomas, and no involvement in Hodgkin lymphoma. The predominant histological pattern of BM involvement was diffused (14/37; 37.8%), followed by interstitial (10/37; 27.1%). Five cases revealed benign nonparatrabecular lymphoid aggregates which could be confused with lymphomatous involvement, especially in low grade lymphomas.

Conclusion A careful examination of the BM biopsies along with clinical history, peripheral blood examination, flow cytometry, and immunohistochemistry will help in arriving at the correct diagnosis.

Prognostic value of bone marrow involvement by clonal immunoglobulin gene rearrangements in follicular lymphoma

Aims

We aimed to evaluate the prognostic value of routine use of PCR amplification of immunoglobulin gene rearrangements in bone marrow (BM) staging in patients with follicular lymphoma (FL).

Methods

Clonal rearrangements were assessed by immunoglobulin heavy and light-chain gene rearrangement analysis in BM aspirates from 96 patients diagnosed with FL and related to morphological detection of BM involvement in biopsies. In 71 patients, results were also compared with concurrent flow cytometry analysis.

Results

BM involvement was detected by PCR in 34.4% (33/96) of patients. The presence of clonal rearrangements by PCR was associated with advanced clinical stage (I–III vs IV; p<0.001), high FL International Prognostic Index (FLIPI) score (0–1, 2 vs ≥3; p=0.003), and detection of BM involvement by morphology and flow cytometry analysis (p<0.001 for both). PCR-positive patients had a significantly poorer survival than PCR-negative patients (p=0.001, log-rank test). Thirteen patients positive by PCR but without morphologically detectable BM involvement, had significantly poorer survival than patients with negative morphology and negative PCR result (p=0.002). The poor survival associated with BM involvement by PCR was independent of the FLIPI score (p=0.007, Cox regression). BM involvement by morphology or flow cytometry did not show a significant impact on survival.

Conclusions

Our results showed that routine use of PCR-based clonality analysis significantly improved the prognostic impact of BM staging in patients with FL. BM involvement by PCR was also an independent adverse prognostic factor.

The bone marrow stroma in hematological neoplasms--a guilty bystander

In the setting of hematological neoplasms, changes in the bone marrow (BM) stroma might arise from pressure exerted by the neoplastic clone in shaping a supportive microenvironment, or from chronic perturbation of the BM homeostasis. Under such conditions, alterations in the composition of the BM stroma can be profound, and could emerge as relevant prognostic factors. In this Review, we delineate the multifaceted contribution of the BM stroma to the pathobiology of several hematological neoplasms, and discuss the impact of stromal modifications on the natural course of these diseases. Specifically, we highlight the involvement of BM stromal components in lymphoid and myeloid malignancies, and present the most relevant processes responsible for remodeling the BM stroma. The role of bystander BM stromal elements in the setting of hematological neoplasms is discussed, strengthening the rationale for treatment strategies that target the BM stroma.

Risk factors for poor treatment outcome and central nervous system relapse in diffuse large B-cell lymphoma with bone marrow involvement

Although several studies have described the prognostic implication of bone marrow (BM) involvement (BMI) in lymphoma, studies focused on BM-involved diffuse large B-cell lymphoma (DLBCL) are very rare and small-sized. This study was performed to examine the prognostic impact of morphologic findings of BMI by lymphoma and risk factors for central nervous system (CNS) relapse in BM-involved DLBCL. Between 1993 and 2005, 675 patients were diagnosed with DLBCL, and 88 patients who had BMI at initial diagnosis were eligible for this study. The median overall survival (OS) and failure-free survival (FFS) of 88 patients were 36.6 and 20.1 months, respectively. When three variables from BM morphologic findings (the pattern of BM infiltration, extent of BMI by lymphoma, and percentage of large cells in the infiltrate) were simultaneously included into multivariate model, the increased extent of BMI by lymphoma (> or =10%) in BM area was the only negative prognostic factor, independent of the International Prognostic Index (IPI). Patients with both lower IPI scores and less extent of BMI showed an excellent prognosis with chemotherapy alone (5-year OS and FFS rates, 80% and 69%). However, morphologic BM features were not independent predictive factors for CNS recurrences. An increased lactate dehydrogenase (LDH) level at initial diagnosis was the only independent predictive factor for CNS relapse. Further efforts should be directed toward finding optimal treatment modalities based on the IPI and the extent of BMI by lymphoma. CNS prophylaxis may be considered only in patients with initial elevated LDH levels.

Bone marrow involvement in follicular lymphoma: Comparison of histology and flow cytometry as staging procedures

Bone marrow (BM) examination is a routine staging procedure in follicular lymphoma (FL). Commonly, both BM histology as well as flow cytometry (FCM) of BM aspirates are performed. In order to compare the diagnostic value of these two techniques, we retrospectively evaluated trephine BM biopsies and listmode data of patients with a confirmed diagnosis of FL, obtained in parallel during a 5-year period. One hundred and thirty nine specimens from 91 patients with FL were eligible for analysis. After joint review, nine cases (6.5%) were reclassified, either in histology (six cases) or FCM (three cases). Seventy nine specimens (57%) showed no infiltration with both methods. Sixty specimens (43%) were scored positive for BM involvement by any of the two techniques. Concordant positive results were obtained in 41 cases (68% of positive BM). False negative results were obtained by FCM in 14 cases (23% of positive BM) and by histology in five cases (8%). Discrepant results between BM histology and FCM are frequent in patients with FL, most likely due to the predominantly paratrabecular infiltration and fibrosis typical for FL. Due to the lower false negative rate, trephine BM biopsy remains crucial for the detection of BM involvement in FL.

Lack of utility of CD20 immunohistochemistry in staging bone marrow biopsies for diffuse large B-cell lymphoma

The utility of CD20 immunohistochemistry in the evaluation of staging bone marrow biopsies of newly diagnosed diffuse large B-cell lymphoma (DLBCL) patients has not been extensively studied. We used 113 routinely processed bone marrow biopsies to study the extent and pattern of involvement by lymphoma and CD20 staining. Twelve (10.6%) of 113 cases had involvement by morphology, and 5 (41.7%) of these showed histologic discordance between the primary site and the bone marrow. All cases with morphologic evidence of bone marrow involvement showed staining for CD20. Four (3.5%) of 113 cases had non-neoplastic aggregates that stained for CD20. One case (0.9%) showed a small benign lymphoid aggregate by immunohistochemistry that was not evident by morphology. Our results demonstrate that CD20 staining did not detect any examples of bone marrow involvement by DLBCL that were not evident by morphology. We conclude that immunohistochemistry for CD20 adds no increase in the sensitivity of detection of bone marrow infiltration by DLBCL.

Diagnosis and Classification of Malignant Lymphoma and Related Entities in the Bone Marrow Trephine Biopsy

The trephine bone marrow (BM) biopsy is an important diagnostic tool in patients with malignant lymphoma. BM examination can serve to establish or confirm a primary diagnosis of lymphoma or to determine the extent of disease dissemination for staging purposes. BM histology renders information which cannot be gained equally from aspirate material, such as spacial distribution and extent of infiltrates, BM cellularity and fibrosis. Furthermore, cytology including flow cytometric immunophenotyping can give false-negative results in BM involvement by lymphoma due to intralesional fibrosis. In addition to morphological examination, the availability of a broad panel of antibodies suitable for paraffin-embedded tissues, in conjunction with less damaging decalcification procedures, nowadays enables us to perform complete immunophenotyping on BM trephines and allows for classification of lymphoma infiltrates according to established algorithms. Molecular determination of clonality and interphase fluorescent in situ hybridization can be employed selectively to resolve difficult cases. This review describes important diagnostic features of malignant lymphoma in the BM, relevant differential diagnoses, and the proper use of ancillary techniques.

Optimal processing of bone marrow trephine biopsy: the Hammersmith Protocol

Specimens of bone marrow trephine biopsy (BMT) are transported and fixed in acetic acid-zinc-formalin fixative, decalcified in 10% formic acid-5% formaldehyde and processed with other specimens to paraffin-wax embedding. Sections, 1-microm-thick, are cut by experienced histotechnologists and used for haematoxylin and eosin, Giemsa, reticulin silver and other histological stains. Further, all immunohistochemical procedures used in the laboratory, including double immunostaining, can be used on these sections with no or minimal modifications. About 10,000 BMT specimens have been analysed using this procedure since 1997 and diseases involving the bone marrow have been classified successfully. More recently, standardised polymerase chain reaction-based analysis and mRNA in situ hybridisation studies have been conducted. Excellent morphology with good antigen, DNA and RNA preservation is offered by the Hammersmith Protocol.

The prognostic impact of bone marrow involvement in patients with diffuse large cell lymphoma varies according to the degree of infiltration and presence of discordant marrow involvement

BACKGROUND

The prognostic significance of marrow involvement in diffuse large cell lymphoma (DLCL) is controversial. Factors that that have been reported to influence prognosis include the pattern and extent of marrow infiltration and histological discordance between the primary site and the bone marrow.

METHODS

Bone marrow biopsies from 172 patients with newly diagnosed DLCL entered in two consecutive trials of the Australasian Leukaemia and Lymphoma Group were analyzed. Progression-free (PFS) and overall survival (OS) were calculated according to the absence or presence of bone marrow involvement (BMI), the extent of lymphomatous infiltration and the presence of histological discordance between the primary site and the bone marrow.

RESULTS

Of 172 patients with DLCL accrued between 1982 and 1990, who were treated with CHOP or CHOP-like regimens, 47 (27%) demonstrated marrow involvement on examination of multiple levels. Seventy two percent (34/47) of patients had discordant marrow involvement (<50% large cells) and 28 had minimal (<10%) involvement; these latter patients with minimal marrow involvement (<10%) had similar PFS & OS to the 113 patients without involvement. Within the group of 47 patients with marrow involvement, an increasing percentage of BM involvement was significantly associated with an increasing percentage of concordant histology and a decreasing PFS & OS.

CONCLUSIONS

Minimal BMI, seen in the majority of patients with DLCL with marrow infiltration, appears not to influence the PFS & OS. However, an increasing degree of marrow involvement is associated with an increasing component of large cells and a poorer prognosis in DLCL patients, independent of other risk factors.

Successful antibiotic treatment of Borreliosis associated pseudolymphomatous systemic infiltrates

The clinical management of late stage Borreliosis can be difficult due to various associated symptoms and signs and cumbersome microbiological tests. We report a case of successful antibiotic treatment of Borreliosis-associated pseudolymphomatous infiltrates in bone marrow and lymph nodes, which were diagnosed by bone marrow trephine biopsy and positron emission tomography.

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.

Immunohistochemistry in bone marrow pathology: a useful adjunct for morphologic diagnosis

Pathomorphological examination of trephine biopsies of the bone marrow (BM) represents a standard method for the diagnosis and staging of hematologic neoplasms and other disorders involving the BM. The increasing knowledge about the genetic basis and biology of hematologic neoplasms, as well as the recently proposed WHO classification system, provide the framework for an accurate diagnosis. Although conventional morphology remains the gold standard for paraffin-embedded BM trephines, immunohistochemical stainings have become an integral part of the diagnostic workup. Antibodies suitable for paraffin sections are generally applicable to BM trephines, but modifications of staining protocols may be necessary due to the alternative fixatives and decalcification procedures used for BM biopsies. The indications for immunostainings range from confirmation and classification of lymphoma involvement, subclassification of acute leukemias, and estimating blast counts in myelodysplastic and myeloproliferative syndromes to characterization of BM involvement in nonhematologic neoplasms. Although subtyping of NHL in the BM is more difficult from the point of morphology, classification of the entities that frequently involve the BM, especially the small B-cell lymphomas, can easily be achieved with the help of immunohistochemistry. In this review, we try to summarize the current state of the art in BM immunohistochemistry for the diagnosis of hematologic disorders. Moreover, diagnostic algorithms and useful antibody panels are proposed for a rational and cost-effective approach.

Increased incidence of monoclonal B-cell infiltrate in chronic myeloproliferative disorders

A total of 106 trephine biopsy specimens with clinical, laboratory and pathology findings corresponding to chronic myeloproliferative disorders (CMPD) were analyzed to reveal the nature of the lymphoid infiltrate in the bone marrow. Histological investigation in 31 chronic myeloid leukemia (CML), 29 CMPDs not otherwise specified (CMPD-NOS), 28 essential thrombocytosis (ET), 15 polycythemia vera (PV) and three chronic eosinophilic leukemia/hypereosinophilic syndrome (CEL/HES) exhibited in 32% various amounts of lymphocytic infiltrate of sparsely to moderately diffuse or nodular types in the bone marrow, but the reactive or coinciding lymphomatous nature could not be revealed by histology alone in the majority of cases. PCR analysis of the immunoglobulin heavy chain (IgH) gene rearrangement was successfully performed in 81 out of the 106 DNA specimens extracted from formol-paraffin blocks. Out of the 81 samples with good-quality DNA, 18 gave a single or double discrete amplification band(s), which was reproducible only in four specimens. Sequencing finally proved monoclonal B-cell population of both pre- and postfollicular origin in all four samples (5%), one CML and three CMPD-NOS. Detailed clinical and pathological investigations indicated overt B-cell malignant lymphoma with clonal relationship to the CMPD in two out of these four patients. We conclude that detailed molecular analysis of IgH gene rearrangement in bone marrow samples of CMPD patients is needed to identify the true monoclonal B-cell infiltration, which-even without overt malignant lymphoma-may occur in this group of disorders. Modern Pathology (2004) 17, 1521-1530, advance online publication, 16 July 2004; doi:10.1038/modpathol.3800225.

Contribution of IgH-PCR to the evaluation of B-cell lymphoma involvement in paraffin-embedded bone marrow biopsy specimens

We investigated whether the determination of clonality by polymerase chain reaction (PCR) analysis of immunoglobulin heavy chain (IgH) gene rearrangements could be helpful in the evaluation of B-cell lymphoma (BCL) involvement of bone marrow (BM) biopsy specimens. We evaluated 83 paraffin-embedded BM biopsy specimens from 26 patients with BCL. When BM biopsy specimens considered positive, "suspicious," or negative by morphologic and immunohistochemical examination were evaluated by PCR, a monoclonal B-cell population was detected in 81% (39/48), 64% (9/14), and 11% (2/18), respectively. In most cases, a reproducible monoclonal IgH gene rearrangement was observed from BM and extramedullary sites. Nevertheless, in 4 cases, a different and independent monoclonal IgH rearrangement was observed during the disease course. PCR is efficient and complementary to morphologic and immunohistochemical examination for the evaluation of BCL involvement of BM biopsy specimens, especially when a reproducible rearrangement is found in 2 different samples.

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.

Specificity of polymerase chain reaction-based clonality analysis of immunoglobulin heavy chain gene rearrangement for the detection of bone marrow infiltrate in B-cell lymphoma-associated haemophagocytic syndrome

As a wide range of disorders underlie haemophagocytic syndrome, a rapid distinction between benign polyclonal and malignant monoclonal lymphoid proliferations is critical. We investigated whether polymerase chain reaction (PCR) amplification of immunoglobulin heavy chain gene rearrangement could efficiently detect clonal B-cell populations in non-diagnostic marrow for B-cell lymphoma-associated haemophagocytic syndrome (B-LAHS). On amplifying two DNA samples per biopsy, no reproducible monoclonal PCR result was found in reactive haemophagocytic marrows. In contrast, four out of nine assessable B-LAHS patients with histomorphologically and immunohistochemically lymphoma-free bone marrow showed a reproducible monoclonal immunoglobulin heavy chain gene rearrangement. At the molecular level, two B-LAHS patients had lymphoma-free marrow as demonstrated by patient-specific PCR, suggesting that haemophagocytic marrow is not always associated with lymphoma involvement. PCR-based demonstration of clonal B-cell populations in marrow would add an extra dimension to B-LAHS diagnosis.

The stromal composition of malignant lymphoid aggregates in bone marrow: variations in architecture and phenotype in different B-cell tumours

We present evidence that different B-cell tumours, in bone marrow, have different relationships to stroma. Marrow core biopsies from 46 patients with B-cell tumours were immunostained with antibodies for distinct stromal cells. Cases included follicular lymphoma (FL), chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL), mantle cell lymphoma (MCL), lymphoplasmacytic lymphoma (LPL), and nodal, extranodal and splenic marginal zone lymphoma (NMZL, MALT, SMZL). In normal marrow, low-affinity nerve growth factor receptor (LNGFR) highlighted a fine network of adventitial reticular cells (ARC). The nodular aggregates of CLL/SLL, NMZL, MALT and SMZL were characterized by distortion of the ARC network and downregulation of LNGFR. In contrast, the aggregates of FL, LPL and MCL were composed of linear arrays of ARC in tight association with individual tumour cells. LNFGR+ was upregulated in ARC associated with the aggregates in FL, LPL and focally in MCL. Upregulation of CD35, vascular cell adhesion molecule (VCAM-1) and CD40 on ARC was noted exclusively in FL. Marrow lymphoid aggregates in CLL/SLL, NMZL, MALT and SMZL probably grow by displacing the pre-existing marrow stroma, while FL and LPL maintain a close association with the ARC network. In FL, expression of follicular dendritic cell-associated markers is modulated in pre-existing marrow stromal cells.

Treatment of chronic myelogenous leukemia with the tyrosine kinase inhibitor STI571 results in marked regression of bone marrow fibrosis

Morphologic bone marrow changes in patients with BCR-ABL-positive chronic myelogenous leukemia (CML) were investigated during treatment with the tyrosine kinase inhibitor STI571. Bone marrow trephine biopsy specimens from 23 pretreated patients with CML were examined morphologically and by morphometry before and 6 weeks and 3 months after the initiation of STI571 therapy (Glivec, Novartis, Basel, Switzerland). Bone marrow changes during treatment showed a quantitative normalization of erythropoiesis, a marked reduction of granulopoiesis, and a significant decrease in megakaryocytes with the reappearance of normal-sized forms. Furthermore, a significant regression of bone marrow fibrosis was observed in patients with initial fibrosis (P <.000,000,001). These results may expand the profile of STI571 and may offer novel therapeutic possibilities in diseases with bone marrow fibrosis.

p27(Kip1) immunostaining for the differential diagnosis of small b-cell neoplasms in trephine bone marrow biopsies

The distinction between mantle cell lymphoma (MCL) and other small B-cell non-Hodgkin lymphomas (NHL) is important because MCL has a more aggressive clinical course. In bone marrow (BM) biopsy specimens, this distinction can be particularly difficult. Although cyclin D1 immunostaining and molecular detection of the t(11;14) translocation are highly specific markers for MCL, they fail to detect a proportion of cases. We have recently described that MCL typically lacks detectable expression of the cyclin-dependent kinase inhibitor p27(kip1) protein by immunostaining, which is expressed at high levels in most small B-cell NHL inversely correlated to the proliferation rate. We therefore examined whether p27(kip1) immunostaining could be a useful adjunct for the differential diagnosis of small B-cell NHL infiltrates in the BM. Trephine BM biopsy specimens of 96 patients, including well-characterized MCL (19 cases), B-cell chronic lymphocytic leukemia (27 cases), follicular lymphoma (18 cases), hairy cell leukemia (22 cases), and marginal zone lymphoma (10 cases) as well as 10 reactive BM, including five with benign lymphoid aggregates were investigated. In addition, the presence of a t(11;14) translocation involving the major translocation cluster was studied by PCR in all MCL. All cases of B-cell chronic lymphocytic leukemia, follicular lymphoma, and marginal zone lymphoma revealed a strong p27(kip1) nuclear staining in the majority of neoplastic cells. Fourteen (78%) cases of MCL were p27(kip1)-negative in the tumor cells, whereas four cases revealed a weak nuclear positivity. Seventeen (77%) cases of hairy cell leukemia were also either completely negative for p27(kip1) or showed a faint positive staining in a minority of the neoplastic cells. Nine of 19 cases (47%) of MCL showed a bcl1 rearrangement involving the major translocation cluster region. These findings demonstrate that p27(kip1) immunostaining is a valuable additional marker for the differential diagnosis of small B-cell NHL infiltrates in BM biopsies. The reduction or lack of p27(kip1) protein expression in MCL, as well as in hairy cell leukemia, might be an important event in the pathogenesis of these disorders.

Amplification of PCR products in excess of 600 base pairs using DNA extracted from decalcified, paraffin wax embedded bone marrow trephine biopsies

AIMS

To establish a robust method of extracting DNA from paraffin wax embedded bone marrow trephine (PBMT) biopsies for the amplification of relatively long polymerase chain reaction (PCR) products.

METHOD

Xylene and ethanol were used to remove paraffin wax from eight formalin fixed, EDTA decalcified PBMT biopsies and DNA extraction was performed using a Qiagen QIAamp tissue kit. The DNA samples were amplified using nine different PCR primers sets, including those used to detect chromosomal translocations (t(11;14) and t(14;18), and clonal B cell populations. A t(11;14) PCR product of approximately 600 base pairs (bp) was sequenced using dye terminator cycle sequencing.

RESULTS

All eight DNA samples extracted from PBMT biopsies were amplified successfully to generate DNA fragments up to 643 bp in length. Chromosomal translocations and immunoglobulin gene rearrangements were detected by PCR in some of the samples. Sequencing of the t(11;14) PCR product demonstrated the presence of chimaeric sequences, which included both bcl-1 and immunoglobulin heavy chain (IgH) gene sequences, consistent with the presence of this translocation.

CONCLUSIONS

This method enables PCR analyses of PBMT biopsies that were not previously possible, offering the prospect of improved accuracy of diagnosis and the monitoring of patients with bone marrow disease.

Specificity of PCR-based clonality analysis of immunoglobulin heavy chain gene rearrangements for the detection of bone marrow involvement by low-grade B-cell lymphomas

A study was performed to investigate the utility of polymerase chain reaction (PCR)-based analysis of immunoglobulin heavy chain (IgH) gene rearrangements for the diagnosis of low-grade malignant B-cell lymphomas on formalin-fixed, EDTA-decalcified, and paraffin-embedded bone marrow trephine biopsies. On amplifying two DNA samples per biopsy, no reproducible monoclonal PCR result was found in 32 patients with reactive lymphoid hyperplasias. In contrast, 5/14 patients with known low-grade B-cell lymphomas, but histomorphologically and immunohistochemically lymphoma-free bone marrow, showed a reproducible monoclonal IgH gene rearrangement. In three of these cases, sequence analysis revealed completely different amplification products on comparing bone marrow and lymph node infiltrations, while in the other two cases the products were identical. In one of the latter biopsies, an unequivocal lymphoma infiltrate was found after step sectioning of the biopsy, while the other case remained lymphoma-free according to conventional criteria. A third group of three patients with known lymphomas and bone marrow findings that were suggestive but not diagnostic of bone marrow involvement showed monoclonal PCR results in all three cases, with identical sequences in bone marrow and extramedullary lymphoma infiltrates. These data suggest that a reproducible monoclonal IgH gene rearrangement is highly specific for the presence of malignant B-cells in bone marrow. In staging procedures for low-grade B-cell lymphomas, PCR yields no additional information in cases that are morphologically and immunohistochemically lymphoma-free after evaluation of representative sections. PCR may be useful in equivocal cases, provided that IgH gene rearrangements of extramedullary lymphoma and bone marrow are sequenced and compared.

Focal lymphoid aggregates (nodules) in bone marrow biopsies: differentiation between benign hyperplasia and malignant lymphoma--a practical guideline

AIMS

To provide practical guidelines for the differentiation between benign and malignant focal lymphoid aggregates (lymphoid nodules) in routinely referred bone marrow trephine biopsies, using a synoptic approach including clinical data and histological workup.

METHODS

For easy identification of very small lymphoid infiltrates the chloroacetate esterase stain was applied as a screening procedure. This allowed the identification of 491 formalin fixed, paraffin wax embedded specimens with one or more lymphoid nodules. Examination of lymphoid infiltrates included such variables as histotopography, demarcation, cytology, reticulin fibres, and immunohistochemistry with a set of monoclonal antibodies (CD20, CD45R, CD45R0, CD3, CD43). Evaluation of clinical and morphological data was carried out independently. In case of malignant lymphomas, a correlation with corresponding lymph node findings was made.

RESULTS

352 patients had benign focal lymphoid aggregates usually associated with systemic autoimmune diseases, chronic myeloproliferative disorders, toxic myelopathy, and viral infections. Discrete nodular infiltrates of (small cell) malignant lymphomas (n = 93) simulating benign hyperplasia were found in chronic lymphocytic leukaemia, germinal centre cell lymphomas (CB-CC), and lymphoplasmacytic/cytoid lymphomas (LPI). In addition to immunoreactivity, certain histological variables proved distinctive. These were: (1) histotopography, that is, localisation of the lymphoid aggregates within the bone marrow space; (2) relation to the surrounding tissue: margination or interstitial spillage of lymphoid cells; and (3) increase in reticulin fibres.

CONCLUSIONS

A combined diagnostic procedure identifying several distinctive features, in particular histotopography and immunohistochemistry, provides a most promising way of discriminating reactive from neoplastic lymphoid nodules in the bone marrow.

Three-dimensional reconstruction of non-Hodgkin's lymphoma in bone marrow trephines

The objective of this study was to analyse the location in the bone marrow of deposits of low-grade non-Hodgkin's lymphoma. This was achieved using computer-generated three-dimensional reconstruction techniques applied to serial tissue sections of five bone marrow trephines involved by lymphoma. For comparative purposes, previously published three-dimensional models of benign lymphoid aggregates in the bone marrow were need. The images generated by this new study showed that deposits of low-grade non-Hodgkin's lymphoma involving the bone marrow always assumed a paratrabecular pattern of infiltration at some point. This is in direct contrast to the pattern of bone marrow infiltration shown by benign lymphoid aggregates. It is concluded that location within the marrow space is a crucial factor in distinguishing between benign and low-grade malignant lymphoid infiltrates in the bone marrow.

Use of methyl methacrylate resin for embedding bone marrow trephine biopsy specimens

AIMS

To evaluate the use of methyl methacrylate resin as an embedding medium for undecalcified bone marrow trephine biopsy specimens.

METHODS

About 2500 undecalcified bone marrow trephine biopsy specimens were processed, and embedded in methyl methacrylate resin. Semithin sections (2-3 microns) were stained by routine tinctorial and immunocytochemical staining methods with a wide range of antibodies using a standard streptavidin biotin horseradish peroxidase technique. Different antigen retrieval pretreatments were evaluated.

RESULTS

Bone marrow trephine biopsy specimens are embedded routinely in methyl methacrylate at the Haematological Malignancy Diagnostic Service at The Leeds General Infirmary. Over 50 different primary antibodies are in current use; for the majority of these, microwave antigen retrieval or trypsin digestion, or both, is either essential or greatly enhances the results.

CONCLUSIONS

Embedding bone marrow trephine biopsy specimens in methyl methacrylate resin retains morphology and permits reliable, high quality immunocytochemistry. This is particularly desirable for the demonstration of neoplastic cells in regenerative marrow after chemotherapy, and in the detection of residual disease after treatment. The use of methyl methacrylate for routine use on bone marrow trephine biopsy specimens is advocated.

Three-dimensional reconstruction of benign lymphoid aggregates in bone marrow trephines

Distinguishing between deposits of low-grade non-Hodgkin's lymphoma and benign lymphoid aggregates in bone marrow trephine sections is a recognized problem in haematopathology. To test the hypothesis that benign lymphoid aggregates do not make contact with a trabecular surface, three-dimensional models were constructed of five serially sectioned bone marrow trephines, containing a total of 19 lymphoid aggregates known to be benign. The computer-generated images showed that benign lymphoid aggregates were located in the central marrow space and did not become paratrabecular. This suggests that a paratrabecular location may help in some cases to distinguish deposits of low-grade non-Hodgkin's lymphoma from benign lymphoid aggregates.

Heavy-chain immunoglobulin gene rearrangement and cytoplasmic immunoglobulin expression in acute monocytic leukemia following primary germ cell tumor

A case of acute monocytic leukemia with rearrangement of the immunoglobulin heavy-chain gene and strong cytoplasmic immunoglobulin expression in a young patient treated with multi-drug chemotherapy for primary seminomatous germ cell tumor 13 months earlier is reported. The short latency period from the beginning of therapy for primary germ cell tumor and the abrupt onset of leukemia with no identifiable prodrome bear similarities to podophyllotoxin-related leukemias.

Bone marrow examination in newly diagnosed Hodgkin's disease: current practice in the United Kingdom

In the UK Hodgkin's disease is usually treated by either clinical oncologists or haematologists. A national study of the performance of bone marrow examination in newly diagnosed Hodgkin's disease was undertaken to establish current practice. A total of 620 questionnaires were despatched, and replies were received from 60% of consultants (45% of clinical oncologists and 70% of haematologists). Bone marrow examination was performed in all new cases significantly more often by haematologists than by clinical oncologists (74% vs 40%, P < 0.001). Among haematologists, there was no correlation between the number of new patients seen annually and practice, however clinical oncologists were even less likely to perform routine bone marrow biopsies if they saw more than ten patients per year (P < 0.02). Where bone marrow examination was performed selectively, the most common criteria used were peripheral blood cytopenia and advanced-stage disease. These criteria were applied in the same way by both clinical oncologists and haematologists. Bone marrow biopsy, an invasive and often painful procedure, is currently performed more frequently in Hodgkin's disease than can be recommended on the basis of recent studies in the literature and associated guidelines. There is a significant difference in practice between clinical oncologists and haematologists, and this raises the wider issue of the influence of hospital specialisation on patient management.

Familial hemophagocytic lymphohistiocytosis associated with disseminated T-cell lymphoma: a report of two siblings

Two siblings with evidence of disseminated T-cell lymphoma at the time of diagnosis of familial hemophagocytic lymphohistiocytosis (FHL) are reported, an association which has not been described previously. The first child with typical clinical and laboratory features of FHL died shortly after admission, before diagnosis could be established. Retrospective analysis of autoptic tissue revealed marked hemophagocytosis as well as morphological and immunohistochemical features suggestive of disseminated T-cell lymphoma. In the second child, FHL was diagnosed in time. Subsequent histologic investigation of bone marrow biopsies displayed a focal infiltration by T-cell lymphoma. DNA hybridization studies provided evidence of a monoclonal T-cell receptor beta chain gene rearrangement. Following conventional chemotherapeutic induction for FHL, the patient received an allogeneic bone marrow transplant (BMT) from a related healthy donor. Currently, 17 months after BMT, the boy is in unmaintained remission from FHL and T-cell lymphoma. The current pathogenetic concepts for FHL and a possible relationship between T-cell lymphoma and FHL are discussed.