Use Of Bone Marrow Biopsy Research Articles

New diagnostic strategy for multiple myeloma: A review

Multiple myeloma (MM) is the second most prevalent hematological malignancy and is distinguished by the aberrant proliferation of monoclonal plasma cells inside the bone marrow and production of M-protein. This condition frequently results in bone deterioration, acute kidney damage, anemia, and hypercalcemia. However, the clinical manifestations and accompanying symptoms of MM vary and may change as the condition evolves. Therefore, diagnosis of MM is difficult. At present, the confirmation of MM diagnosis necessitates the use of bone marrow biopsy, a procedure that is both invasive and challenging for assessing dynamic alterations in the disease. The integration of laboratory testing technologies with imaging technology has the potential to enhance the diagnostic effectiveness and provide a thorough evaluation of disease progression and prognosis in patients with MM. All the examination methods have advantages and disadvantages. Therefore, diagnosis is determined by the application of clinical characteristics, serological tests, and imaging investigations.

Patterns of bone marrow infiltration in lymphomas- A retrospective descriptive analysis from a tertiary care centre in Southern India

Bone marrow biopsy (BMB) examination is the gold standard for staging of lymphoma which is interpreted along with other clinical, laboratory and radiological investigations. This study aimed to evaluate the various patterns of BMB infiltration by lymphomas which include Hodgkin and Non Hodgkin lymphoma and the usefulness of BMB compared to bone marrow aspiration (BMA). : In a period of three years, there were 212 cases which showed lymphoma infiltration in bone marrow. We assessed the peripheral blood smear (PBS), BMA and BMB slides and concordance between each was evaluated. BMB slides were assessed for the pattern of involvement. The most frequent subtype was chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) (21.70%) followed by Hodgkin lymphoma (HL)(12.73%)and follicular lymphoma (FL)(11.32%). Predominant pattern of infiltration showed by CLL/SLL cases was mixed pattern, by FL was paratrabecular pattern, mantle cell lymphoma(MCL) showed either diffuse or nodular, diffuse large B cell lymphoma (DLBCL) and Burkitt lymphoma(BL) showed predominantly diffuse pattern. Hairy cell leukemia (HCL) and peripheral T cell lymphoma (PTCL) showed an interstitial pattern. In HL, the pattern was usually focal nodular however diffuse involvement was seen in a few. Of the 212 cases, 50.94% cases had atypical lymphocytes or lymphocytosis in PBS and 81.14% cases showed infiltration in BMA. Atypical lymphoid cells may not be present at times in peripheral blood or bone marrow aspirate in spite of infiltration in the bone marrow. Different lymphomas show characteristic patterns of marrow involvement.

Evaluation of the Prognostic Utility of Bone Marrow Biopsy in Diffuse Large B-Cell Lymphoma: A SEER-Medicare Linked Database Analysis

Background: Positron emission tomography-computed tomography (PET-CT) has become the primary modality for initial staging in diffuse large B-cell lymphoma (DLBCL) [Barrington et al, J Clin Oncol 2014; Cheson et al, J Clin Oncol 2014]. Recently, the role of a staging bone marrow biopsy (BMB) has become less clear. A meta-analysis suggested that PET-CT can miss bone marrow involvement [Adams et al, Eur J Nucl Med Mol Imaging 2014], but recent guidelines on staging suggested that BMB should be optional. We analyzed temporal trends in use of different screening modalities and evaluated the association between patient outcomes and staging modality (PET-CT with BMB compared to either PET-CT without BMB or CT with BMB) in patients with DLBCL in SEER-Medicare. We hypothesized that use of PET-CT as screening would increase over time and that use of BMB would decrease over time. We also hypothesized that use of BMB would not be associated with an improvement in overall survival in patients staged with PET-CT. Methods: 70,858 patients diagnosed with DLBCL in SEER-Medicare were identified with ICD-O-3 SEER histology codes 9680 and 9684. In this analysis, we included 7,159 patients who were diagnosed between 2002 and 2015, were treated with first-line rituximab, cyclophosphamide, vincristine, and doxorubicin chemotherapy regimens, and had claims for PET-CT and/or BMB within 30 days on either side of diagnosis. The patients were divided into screening categories of patients receiving PET-CT without BMB (PET-CT w/o BMB), patients receiving BMB with CT (i.e., no PET-CT) (CT w/ BMB), and patients receiving both screening modalities (PET-CT w/ BMB). Overall survival (OS) was calculated from date of diagnosis to death. Kaplan-Meier (KM) curves were used to estimate survival probabilities across screening categories and log-rank tests (LRT) were used to statistically evaluate differences between OS curves. Cox proportional hazards (CoxPH) models were used to estimate hazard ratios prior to and following adjustment for confounders. Results: 2,059 patients received PET-CT w/o BMB, 1,539 received CT w/ BMB, and 3,561 received PET-CT w/ BMB. Proportions of patients receiving PET-CT w/ BMB and PET-CT w/o BMB increased across years of diagnosis (36.7 to 51.9% and 17.4 to 36.1%, respectively, between 2002-2005 and 2013-2015), while the proportion of patients receiving CT w/ BMB decreased across years of diagnosis (45.8 to 12.0%) (Table 1). Similarly, the proportion of patients receiving BMB independent of imaging modality also decreased (28.8% to 16.8%). In bivariate analyses, categories of screening were significantly associated with age category, sex, year of diagnosis, race, stage, nodal status, poor performance status, Charlson Comorbidity Index (CCI), number of first-line cycles, and geographic classification, with receipt of PET-CT w/ BMB being more common in patients who are younger, male, diagnosed in later years in urban settings, and received >4 first-line cycles, with earlier stage at diagnosis, nodal disease, good performance status, and lower CCI (Table 1). In unadjusted KM analysis, median survival among patients receiving PET-CT w/ BMB was 8.7 years, compared to 8.1 and 7.6 years among patients receiving PET-CT w/o BMB and CT w/ BMB, respectively (LRT P<0.0001; Figure 1). In fully adjusted CoxPH models, patients receiving PET-CT w/ BMB did not have a significantly better OS compared to those receiving PET-CT w/o BMB (HR: 0.93; 95% CI, 0.84-1.02; P=0.1075). Separately, patients receiving CT w/ BMB had a significantly worse OS compared to those receiving PET-CT w/o BMB (HR: 1.13; 95% CI, 1.02-1.26; P=0.0212), even though OS was not significantly associated with year of diagnosis (P=0.6613). Conclusions: In this SEER-Medicare cohort of 7,159 patients with newly diagnosed DLBCL, we found temporal trends supporting increased use of pretreatment staging PET-CT and decreased use of BMB. We also found that use of PET-CT w/ BMB did not provide a survival benefit as compared to use of PET-CT w/o BMB. These data would suggest that use of BMB could be spared in patients newly diagnosed with DLBCL over the age of 65, unless otherwise clinically indicated. Interestingly, the finding of no OS benefit across years of diagnosis suggests that improvements in outcomes in recent trials may be due to patient selection. Given the limitations associated with registry data, the study warrants replication in more complete DLBCL data sets. Disclosures Rutherford: Genentech/Roche: Research Funding; Karyopharm: Consultancy, Research Funding; Regeneron: Research Funding; Celgene: Consultancy; Kite: Consultancy; Dova: Consultancy; Seattle Genetics: Consultancy; AstraZeneca: Consultancy; LAM Therapeutics: Research Funding; Heron: Consultancy; Juno: Consultancy. Leonard:Miltenyi: Consultancy; Karyopharm: Consultancy; Gilead/Kite: Consultancy; Sutro: Consultancy; Bayer: Consultancy; BMS/Celgene: Consultancy; MEI Pharma: Consultancy; Epizyme: Consultancy; Roche/Genentech: Consultancy; Regeneron: Consultancy; ADC Therapeutics: Consultancy; GenMab: Consultancy; AstraZeneca: Consultancy. Martin:Kite: Consultancy; Morphosys: Consultancy; Regeneron: Consultancy; Karyopharm: Consultancy, Research Funding; Janssen: Consultancy; Sandoz: Consultancy; I-MAB: Consultancy; Bayer: Consultancy; Incyte: Consultancy; Cellectar: Consultancy; Beigene: Consultancy; Celgene: Consultancy; Teneobio: Consultancy.

Quality Initiative in Clinical Practice: A Single-Institution Appraisal of Quality Metrics in the Management of Newly Diagnosed Diffuse Large B-Cell Lymphoma

ObjectiveTo assess our adherence to treatment guidelines for diffuse large B-cell lymphoma (DLBCL) established by the American Society of Hematology in 2014 through implementation of a quality improvement initiative (QII) at our institution in 2015.Patients and MethodsPatients with newly diagnosed DLBCL treated from January 1, 2006, through December 31, 2017, were identified. Electronic medical records were reviewed for documentation of American Society of Hematology Practice Improvement Module quality measures (eg, key pathologic features of DLBCL, lymphoma staging, and screening for hepatitis B virus [HBV] infection in patients receiving rituximab-based chemotherapy). We also reviewed assessment of prognosis by revised International Prognostic Index score, testing for hepatitis C virus, HBV, and HIV, chemotherapy education, and the addition of rituximab in the treatment regimen of CD20+ DLBCL.ResultsFollowing QII implementation, we saw improvements in most metrics, including reporting of key molecular features (fluorescence in situ hybridization for c-MYC, BCL2, and BCL6, from 45.5% [75 of 165 patients] before QII to 91.7% [22 of 24 patients] after QII; P<.001), screening for HBV (41.8% [69 of 165 patients] to 91.7% [22 of 24 patients]; P<.001) and HIV infections (33.9% [56 of 165 patients] to 87.5% [21 of 24 patients]; P<.0001), providing chemotherapy education (92.7% [153 of 165 patients] to 100%), and use of rituximab for CD20+ DLBCL (83.6% [138 of 165 patients] to 100%; P=.05). All patients had positron emission tomography–computed tomography for DLBCL staging, and there was significantly lower use of bone marrow biopsy (P=.011).ConclusionImplementating a QII and employing standardized metrics can aid in improving quality of care for patients with newly diagnosed DLBCL and allow opportunities to build and ensure better adherence to evolving patient care guidelines.

Quality Initiative in Clinical Practice: A Single Institution Appraisal of Quality Metrics in the Management of Newly Diagnosed Diffuse Large B-Cell Lymphoma Based on the American Society of Hematology Practice Improvement Module

▪ABSTRACTBackground: In 2014, the American Society of Hematology (ASH) established a practice improvement module (PIM) incorporating quality metrics for management of diffuse large B cell lymphoma (DLBCL). Such PIMs have allowed physicians to monitor the quality of care in their practice. We implemented a DLBCL quality improvement initiative (QII) at our institution in January, 2015. In an appraisal of this initiative, we reviewed the ASH PIM metrics and included several others to assess adherence to guidelines for treatment of DLBCL and to examine the need for institutional improvement.Methods: Patients who were newly diagnosed with DLBCL and received treatment at our institution from January 2006 through December 2017 were identified. Electronic medical records were reviewed for documentation of ASH PIM quality measures (e.g., key pathologic features of DLBCL, lymphoma staging, screening for hepatitis B virus (HBV) infection in patients receiving rituximab-based chemotherapy, etc). We also reviewed the proportion of patients who had assessment of prognosis by revised International Prognostic Index (r-IPI) score, testing for hepatitis C (HCV), HIV viral infections, chemotherapy education, and the addition of rituximab in the treatment regimen of CD20+ DLBCL.Results: Following implementation of the QII, our institution saw improvement in most quality metrics. Particularly significant were improvements in reporting of key molecular features (45.45% to 91.6%, P < 0.0001), screening for HBV (41.82% to 91.67%, P < 0.001) and HIV infections (33.94% to 87.5%, P < 0.0001). All patients post-QII had a PET-CT scan for staging of DLBCL and there was a significantly lower use of bone marrow biopsy (61.2% to 33.33%, P = 0.011).Conclusion: Implementation of a quality initiative and employing standardized metrics can aid in improving institutional quality of care for patients with newly diagnosed DLBCL, and allows opportunity to build and ensure better adherence to evolving national and professional patient care guidelines. DisclosuresNo relevant conflicts of interest to declare.

Rethinking the usefulness of bone marrow biopsy on treatment decision in CLL patients at diagnosis.

We aimed to investigate the role of bone marrow infiltration pattern (BMIP) and bone marrow reticulin fibrosis (BMRF) in determining treatment demand in patients with diagnosis of chronic lymphocytic leukemia (CLL). We retrospectively evaluated the data of 65 patients, who were followed with the diagnosis of CLL at Istanbul Training and Research Hospital, Department of Hematology, between July 2007 and June 2016. The median age of the patients was 64years (range, 32-83). Twenty-three (35.4%) patients were female, and 42 (64.6%) were male. Early/mild grade BMRF was observed in 46 (70.8%) patients and advanced grade BMRF in 19 (29.2%) patients. Eleven (23.9%) of 46 patients with early/mild grade BMRF and 10 (52.9%) of 19 patients with advanced grade BMRF required treatment during follow-up (p=0.04). According to the BMIP, 14 (21.5%) patients had diffuse and 51 (78.5%) patients had non-diffuse BMIP. Eleven (78.6%) of 14 patients with diffuse BMIP and 10 (19.6%) of 51 patients with non-diffuse BMIP required treatment during follow-up (p<0.001). In univariate analysis, both advanced grade BMRF and diffuse BMIP had an impact on occurrence of treatment demand (p=0.028, HR=3.535 vs. p<0.01 HR=15.033). Multivariate analysis also revealed diffuse BMIP to be effective (p<0.001, HR 13.089), while advanced grade BMRF failed to significantly influence treatment demand (p=0.140, HR 2.664). In conclusion, in the light of our findings, it is reasonable to consider that bone marrow biopsy at the time of diagnosis might provide a preliminary information about treatment demand in patients with CLL.

Changing patterns of AIDS: impact on the indications and diagnostic yield of bone marrow biopsies

After the advent of HAART, the clinical course of HIV infection has dramatically improved. Therefore, it seems appropriate to reevaluate the performance of bone marrow biopsy (BMB) as a diagnostic tool. The aim of the present study was to compare the reasons for performing a BMB and its diagnostic yield in HIV-patients before and after HAART. A total of 165 BMB specimens obtained from HIV-infected patients receiving care at the Hospital of Universidade Federal do Rio de Janeiro in two different periods (1986-1994 and 1999-2004) were analysed. The main reason for BMB examination in the first period was fever (88%), which decreased in the second period (57%, p < 0.0001), when cytopenia (51%) was the leading reason for BMB, whereas in the first period it accounted for only 30% (p = 0.008). A definitive diagnosis (infection, granulomas or lymphomas) was obtained in 28% of patients in the first period and in 19% during the second period (p = 0.20). The diagnosis turned out as infections decreased from 16% in period 1 to 2% in period 2 (p = 0.003). Despite the the limitations in the evaluation of fever, the use of BMB must be considered on an individual basis, whenever less invasive alternatives have been exhausted, and should be complemented by a bone marrow aspiration for microbiological studies.

Yield of Bone Marrow Examination in Diagnosing the Source of Fever of Unknown Origin

Fever of unknown origin (FUO) still remains a diagnostic challenge, while diagnosis may remain obscure for several weeks or months. The role of tissue biopsy is crucial in the diagnostic approach. We report a series of 130 consecutive patients with FUO who had undergone a bone marrow biopsy (BMB). Among 280 consecutive nonimmunocompromised patients hospitalized between 1995 and 2005 for a febrile illness of uncertain cause, lasting at least 3 weeks, with no diagnosis after an appropriate minimal diagnostic workup, 130 underwent BMB. Overall, a specific diagnosis was achieved by BMB and histological examination in 31 cases (diagnostic yield, 23.7%). Three types of diseases were found: hematological malignant diseases in 25 cases, including 19 patients with malignant lymphoma, 4 with acute leukemia, 1 with hairy cell leukemia, and 1 with multiple myeloma; infectious diseases in 3 cases; systemic mastocytosis in 2 cases; and disseminated granulomatosis in 1 case. Thrombocytopenia (odds ratio, 4.9; 95% confidence interval, 1.04-9.30) and anemia (odds ratio, 3.24; 95% CI, 1.13-9.34) were the most reliable predictive factors regarding the usefulness of BMB. Bone marrow cultures had very limited value in our cohort. Finally, corticosteroid use did not seem to affect the yield of BMB. Bone marrow biopsy is a useful technique for the diagnosis of prolonged fever in immunocompetent patients. Thrombocytopenia and anemia seem to be correlated with the value of this test.

Bone marrow fibrosis in childhood acute lymphoblastic leukemia correlates to biological factors, treatment response and outcome

We retrospectively evaluated reticulin fiber density (RFD) in 166 diagnostic bone marrow (BM) biopsies and 62 biopsies obtained at treatment day 29 from children with acute lymphoblastic leukemia (ALL). Patients with B-cell precursor (BCP)-ALL showed higher RFD as compared to patients with T-cell ALL (P<0.001). RFD correlated negatively with white blood cell count (P=0.008) in BCP-ALL patients. Patients with high-hyperdiploid ALL (51-61 chromosomes), no high-risk criteria and low RFD showed a favorable outcome when compared to similar patients with high RFD (P=0.002). In BCP-ALL patients, RFD at diagnosis correlated to the levels of minimal residual disease (MRD) analyzed by flow cytometry on treatment day 29 (P=0.001). Accordingly, patients with MRD > or = 10(-4) presented higher RFD at diagnosis compared to patients with MRD < 10(-4) (P=0.003). BCP-ALL patients with low RFD at diagnosis and a rapid reduction of RFD on day 29 had a favorable outcome compared to patients with the same baseline RFD level at diagnosis but a slow RFD reduction (P=0.041). To our knowledge, these findings are novel and may indicate BM fibrosis as a new valuable prognostic marker in childhood ALL. Expanded use of BM biopsy both at diagnosis and during follow-up is suggested.

Bone Marrow Fibrosis Evaluation in Childhood Acute Lymphoblastic Leukaemia: Correlation to Biological Factors and Treatment Response.

Fibrosis may complicate bone marrow (BM) disease and in its advanced stage negatively affect the outcome of the patients due to BM failure, particularly in myeloproliferative disorders. Studies of the potential importance of BM fibrosis are rare in childhood acute lymphoblastic leukemia (ALL). We have previously shown a prognostic impact of BM fibrosis measured as reticulin fibre density (RFD) at diagnosis in childhood ALL. To further investigate the consequence of BM fibrosis in childhood ALL in relation to immunophenotype, cytogenetic findings and minimal residual disease (MRD) we retrospectively evaluated the RFD in 139 diagnostic BM biopsies from patients with a total mean follow up time of five years and eight months from two childhood oncology centers in Sweden. Patients with pre-B-ALL showed a higher mean RFD (19.1%) compared to patients with T-ALL (11.4%, p < 0.001). This was true also when comparing high-risk (HR) pre-B-ALL patients (18.1%) with the T-ALL patients (p = 0.002). RFD correlated inversely with the white blood cell count in the HR group (r = −0.41, p = 0.009), probably reflecting our finding of low degree of fibrosis in T-ALL. The cytogenetic analysis revealed that for patients with a hyperdiploid ALL (modal chromosome number: 51–61, n: 41) in the low-risk (LR) group, mean RFD was higher for relapsed patients (22.6%) compared to patients in continuous complete remission (17.2%, p = 0.019). The probability of disease free survival for the same group using RFD cutoff of 21.1%, representing the upper third of the material, was 85%±8% for patients with hyperdiploid ALL and low RFD compared to 51%±14% for patients with hyperdiploid ALL and high RFD (p = 0.01, Figure 1). Data for 32 of the patients demonstrated an association between high RFD at diagnosis and high minimal residual disease (MRD) on day 29 after start of treatment. Patients with FACS-MRD > 10−3 day 29 displayed higher mean RFD at diagnosis (21.2%) compared to patients with FACS-MRD < 10−3 (16.7%, p = 0.027, Figure 2). When analyzing the PCR-MRD data day 29 the findings were similar. We conclude that RFD is higher in pre-B-ALL compared to T-ALL, that RFD has prognostic impact in LR patients with hyperdiploid ALL and that high RFD at diagnosis is associated to high MRD on treatment day 29. All these findings are to our knowledge novel, suggesting that evaluation of BM fibrosis at diagnosis is a potentially new therapy stratifying factor and support the need of further research on BM fibrosis in childhood ALL and expanded use of BM biopsy at diagnosis. [Display omitted] [Display omitted]

An Aggressive Bone Marrow Evaluation Including Immunocytology With GD2 for Advanced Retinoblastoma

There is general agreement that bone marrow (BM) examination for staging in patients with retinoblastoma should be limited to cases with advanced disease. However, there are limited data about the yield of sampling multiple sites with aspirations and biopsies and immunocytology. Our policy for BM examination included: 2 aspirates and 2 biopsies at the posterior iliac crest scheduled only for cases with postlaminar optic nerve extension (n=56), scleral invasion (n=10) or orbital (n=5) or metastatic disease at diagnosis (n=7) or at extraocular relapse (n=18). Immunocytology with the antibodies 3A7 or 3F8 for the ganglioside GD2 was performed. From 1/1994 to 3/2005, 277 newly diagnosed patients and 5 at extraocular relapse were included. BM invasion was not found in any of the 66 patients enucleated with disease confined to the globe, but was found in 11/27 of those with overt extraocular disease. There were 2/11 cases with at least 1 negative aspirate with positive biopsy and/or immunocytology for GD2. GD2 positivity was found in 9/9 cases. A more aggressive BM evaluation has a low yield in enucleated patients with high-risk features but disease limited to the globe. However, in cases with overt extraocular dissemination, the use of BM biopsy and immunocytology for GD2 allowed for the detection of cases that would have been missed by aspirations alone. GD2 was intensively expressed and it may also be used to monitor disease response and the presence of minimal residual disease.

The Yield of Bone Marrow Biopsy and Culture Compared with Blood Culture in the Evaluation of HIV-infected Patients for Mycobacterial and Fungal Infections

Purpose: To compare the clinical utility of bone marrow biopsy and culture specimens with blood cultures for mycobacterial and fungal infections among human immunodeficiency virus (HIV)-infected patients. Patients and Methods: All bone marrow biopsies obtained from HIV-infected patients at the University of Alabama at Birmingham (UAB) Medical Center during 1993 to 1995 were blindly reviewed in a standardized format. Bone marrow culture results and blood culture results obtained within 6 weeks of each bone marrow study were compiled. Medical records were reviewed to determine indications for performing bone marrow biopsies, empiric or prophylactic antimicrobial therapies preceding the biopsy, and CD4 counts. Results: Eighty-two bone marrow studies were obtained from 76 patients. Most were performed during the evaluation of fever, cytopenia, or weight loss. Of 55 bone marrow mycobacterial cultures, 13 yielded Mycobacterium avium complex (MAC) and 2 yielded M tuberculosis (MTB). Of 51 bone marrow fungal cultures performed, 2 yielded Cryptococcus neoformans and 1 Histoplasma capsulatum. All patients with a bone marrow culture positive for MAC had a CD4 count of 20 cells/mm 3 or less. The mean CD4 count in this group (±95% confidence interval) (8 ± 3 cells/mm 3) was lower than that of culture-negative cases (41 ± 25 cells/mm 3); P <0.015). When bone marrow cultures and mycobacterial blood cultures were concurrently obtained, results were usually in agreement between the two sites. The mean time until the report of positive mycobacterial bone marrow cultures (22 ± 5 days) was similar to that for blood cultures (24 ± 3 days). Most (84%) patients with multiple mycobacterial cultures had completely concordant results (all positive or all negative). When blood or bone marrow culture yielded mycobacteria, only 29% of the corresponding bone marrow examinations revealed stainable acid-fast bacilli (AFB). In contrast, all 3 cases with positive fungal bone marrow cultures also had stainable organisms on histologic examination. Conclusions: The combined use of bone marrow biopsy and culture as well as blood cultures provide the maximum diagnostic yield when evaluating patients with AIDS for mycobacterial or fungal infections. However, when mycobacterial infections were diagnosed, bone marrow results seldom provided more immediate or specific information than lysis centrifugation blood cultures. A single lysis centrifugation blood culture should be the first step in the routine evaluation of HIV-infected patients when disseminated MAC infection is suspected.

Incidence and histological features of bone marrow involvement in malignant lymphomas.

Bone marrow biopsy (BMB) is a routine investigation in the diagnosis and staging of Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL), and there is evidence supporting its prognostic importance in some histological varieties. The histological characteristics of BMB in 433 NHL and 155 HD patients were reviewed for clinicopathological correlations; 36 of these cases were also studied by means of immunohistochemistry. BM infiltrates were discovered in 171 NHL patients. In 36 cases, the diagnosis of NHL was directly established by BMB; a discordance between lymph node and BM histology was observed in 38 of the other 135 cases. BM-positive centroblastic and immunoblastic NHL were significantly associated with larger infiltrates, BM fibrosis, and megakaryocytic hyperplasia. Leukemization at diagnosis was more frequent in low-malignancy NHL. No correlation was found between histology and prognosis, although immunohistochemistry revealed a B-cell phenotype in all but two cases. BMB was positive in 18 of the 155 HD patients and directly diagnostic in two; Reed-Sternberg and Hodgkin cells were CD-30 positive and surrounded by T-cell infiltration. The concordance between BM and lymph node histology was fairly satisfactory, although the relationships between BM infiltration and other histological parameters may reflect peculiar interactions with BM microenvironmental factors. The usefulness of BMB in the diagnosis of malignant lymphomas has been demonstrated, and further progress can be expected from the availability of reliable immunohistochemical markers of clonality reacting on paraffin-embedded BM sections.