Genetic heterogeneity of diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common form of lymphoma in adults. The disease exhibits a striking heterogeneity in gene expression profiles and clinical outcomes, but its genetic causes remain to be fully defined. Through whole genome and exome sequencing, we characterized the genetic diversity of DLBCL. In all, we sequenced 73 DLBCL primary tumors (34 with matched normal DNA). Separately, we sequenced the exomes of 21 DLBCL cell lines. We identified 322 DLBCL cancer genes that were recurrently mutated in primary DLBCLs. We identified recurrent mutations implicating a number of known and not previously identified genes and pathways in DLBCL including those related to chromatin modification (ARID1A and MEF2B), NF-κB (CARD11 and TNFAIP3), PI3 kinase (PIK3CD, PIK3R1, and MTOR), B-cell lineage (IRF8, POU2F2, and GNA13), and WNT signaling (WIF1). We also experimentally validated a mutation in PIK3CD, a gene not previously implicated in lymphomas. The patterns of mutation demonstrated a classic long tail distribution with substantial variation of mutated genes from patient to patient and also between published studies. Thus, our study reveals the tremendous genetic heterogeneity that underlies lymphomas and highlights the need for personalized medicine approaches to treating these patients.

Chromosome instability in diffuse large B cell lymphomas is suppressed by activation of the noncanonical NF-κB pathway.

Diffuse large B cell lymphoma (DLBCL) is the most common form of lymphoma in the United States. DLBCL comprises biologically distinct subtypes including germinal center-like (GCB) and activated-B-cell-like DLBCL (ABC). The most aggressive type, ABC-DLBCL, displays dysregulation of both canonical and noncanonical NF-κB pathway as well as genomic instability. Although, much is known about the tumorigenic roles of the canonical NF-kB pathway, the precise role of the noncanonical NF-kB pathway remains unknown. Here we show that activation of the noncanonical NF-κB pathway regulates chromosome stability, DNA damage response and centrosome duplication in DLBCL. Analysis of 92 DLBCL samples revealed that activation of the noncanonical NF-κB pathway is associated with low levels of DNA damage and centrosome amplification. Inhibiting the noncanonical pathway in lymphoma cells uncovered baseline DNA damage and prevented doxorubicin-induced DNA damage repair. In addition, it triggered centrosome amplification and chromosome instability, indicated by anaphase bridges, multipolar spindles and chromosome missegregation. We determined that the noncanonical NF-κB pathway execute these functions through the regulation of GADD45α and REDD1 in a p53-independent manner, while it collaborates with p53 to regulate cyclin G2 expression. Furthermore, this pathway regulates GADD45α, REDD1 and cyclin G2 through direct binding of NF-κB sites to their promoter region. Overall, these results indicate that the noncanonical NF-κB pathway plays a central role in maintaining genome integrity in DLBCL. Our data suggests that inhibition of the noncanonical NF-kB pathway should be considered as an important component in DLBCL therapeutic approach.

Deep sequencing of the small RNA transcriptome of normal and malignant human B cells identifies hundreds of novel microRNAs.

A role for microRNA (miRNA) has been recognized in nearly every biologic system examined thus far. A complete delineation of their role must be preceded by the identification of all miRNAs present in any system. We elucidated the complete small RNA transcriptome of normal and malignant B cells through deep sequencing of 31 normal and malignant human B-cell samples that comprise the spectrum of B-cell differentiation and common malignant phenotypes. We identified the expression of 333 known miRNAs, which is more than twice the number previously recognized in any tissue type. We further identified the expression of 286 candidate novel miRNAs in normal and malignant B cells. These miRNAs were validated at a high rate (92%) using quantitative polymerase chain reaction, and we demonstrated their application in the distinction of clinically relevant subgroups of lymphoma. We further demonstrated that a novel miRNA cluster, previously annotated as a hypothetical gene LOC100130622, contains 6 novel miRNAs that regulate the transforming growth factor-ß pathway. Thus, our work suggests that more than a third of the miRNAs present in most cellular types are currently unknown and that these miRNAs may regulate important cellular functions.

Multimodality Technologies in the Assessment of Hematolymphoid Neoplasms.

Accurate assessment of tissues for hematolymphoid neoplasms requires an integrated multiparameter approach. Although morphologic examination by light microscopy remains the mainstay of initial assessment for hematolymphoid neoplasms, immunophenotypic analysis by immunohistochemistry and/or flow cytometry is essential to determine the pattern of differentiation and to detect minimal disease when morphology is inconclusive. In some cases, immunophenotypic analysis provides additional information for targeted immunotherapy and prognostication. Genotypic studies, including cytogenetics, fluorescence in situ hybridization, DNA microarray, polymerase chain reaction, and/or next-generation sequencing, are also imperative for subclassification of the genetically defined disease entities in the current World Health Organization classification of hematolymphoid neoplasms. Moreover, genotypic studies can establish clonality, stratify patients to determine appropriate treatment, and monitor patients for treatment response.

Presence of p16 hypermethylation and Epstein-Barr virus infection in transplant-associated hematolymphoid neoplasm of the skin.

BACKGROUND: Epstein-Barr virus (EBV) is associated with the malignant transformation of B, T, and NK lymphocytes in humans, especially in immunosuppressed individuals. OBJECTIVE: We describe an unusual case confined to the skin in a 39-year-old African American female following a renal transplant. METHODS: Morphologically and immunophenotypically, the tumor was best classified as a plasmablastic lymphoma; however, the neoplastic population revealed rearrangements of both immunoglobulin heavy chain (IgG) and T cell receptor gamma (TCR-gamma). In situ hybridization demonstrated the presence of Epstein-Barr early RNA species (EBER) in the lymphoma cells, consistent with EBV infection. RESULTS: We have previously demonstrated that EBV-induced reactive oxygen is associated with hypermethylation of the tumor suppressor gene p16 in Burkitt lymphoma, and that p16 hypermethylation is nearly always associated with EBV infection in Burkitt lymphoma. LIMITATIONS: Further studies are needed to determine whether p16 is widely suppressed in immunosuppression-induced lymphoma. CONCLUSION: In this study, we demonstrated high levels of hypermethylation of the tumor suppressor gene p16, thus supporting the role of EBV as a carcinogen in post-transplant lymphoproliferative disease.

Clinical significance of quantitative monitoring and mutational analysis of BCR-ABL1 transcript in Philadelphia chromosome positive B lymphoblastic leukemia.

Quantitative detection of BCR-ABL1 transcript is essential in monitoring residual disease of Philadelphia chromosome positive B lymphoblastic leukemia (Ph+ B-LL). We studied the kinetics of BCR-ABL1 transcript in 41 Ph+ B-LL patients in correlation with their clinical outcome. A total of 23 patients achieved complete molecular remission at 6 months post-treatment. This was associated with a lower relapse risk and better overall survival. Likewise, sustainable complete molecular remission in 27 patients was associated with superior clinical outcome. Sporadic low level BCR-ABL1 was detected in 12 of 27 patients who had attained complete molecular remission. The relapse rate was significantly higher in non-transplant patients with persistent positive BCR-ABL1 than patients transplanted when BCR-ABL1 was detectable. All eight patients harboring ABL1 kinase domain mutations died of disease or were transferred to hospice care. We concluded that monitoring the level of BCR-ABL1 transcript after hematologic remission has predictive value to the long-term outcome.

Clinical Validation and Implementation of a Targeted Next-Generation Sequencing Assay to Detect Somatic Variants in Non-Small Cell Lung, Melanoma, and Gastrointestinal Malignancies.

We tested and clinically validated a targeted next-generation sequencing (NGS) mutation panel using 80 formalin-fixed, paraffin-embedded (FFPE) tumor samples. Forty non-small cell lung carcinoma (NSCLC), 30 melanoma, and 30 gastrointestinal (12 colonic, 10 gastric, and 8 pancreatic adenocarcinoma) FFPE samples were selected from laboratory archives. After appropriate specimen and nucleic acid quality control, 80 NGS libraries were prepared using the Illumina TruSight tumor (TST) kit and sequenced on the Illumina MiSeq. Sequence alignment, variant calling, and sequencing quality control were performed using vendor software and laboratory-developed analysis workflows. TST generated ≥500× coverage for 98.4% of the 13,952 targeted bases. Reproducible and accurate variant calling was achieved at ≥5% variant allele frequency with 8 to 12 multiplexed samples per MiSeq flow cell. TST detected 112 variants overall, and confirmed all known single-nucleotide variants (n = 27), deletions (n = 5), insertions (n = 3), and multinucleotide variants (n = 3). TST detected at least one variant in 85.0% (68/80), and two or more variants in 36.2% (29/80), of samples. TP53 was the most frequently mutated gene in NSCLC (13 variants; 13/32 samples), gastrointestinal malignancies (15 variants; 13/25 samples), and overall (30 variants; 28/80 samples). BRAF mutations were most common in melanoma (nine variants; 9/23 samples). Clinically relevant NGS data can be obtained from routine clinical FFPE solid tumor specimens using TST, benchtop instruments, and vendor-supplied bioinformatics pipelines.

Tenascin and microvessel stromal changes in patients with non-Hodgkin's lymphoma are isolated to the sites of disease and vary in correlation to disease activity.

This study investigated stromal changes in expression of tenascin and vasculogenesis in lymphoma. Documenting the dynamic nature of the stromal changes in lymphoma in relation to response to therapy is helpful in planning new therapies directed at these targets. Two hundred and sixty one samples from 111 patients with varying types of non-Hodgkin's lymphoma were reviewed and examined using immunohistochemistry techniques. Samples were stained for factor VIII - related antigen for microvessel density (MVD) analysis and anti-tenascin antibody for qualitative assessment of the stromal expression. Multiple samples from the same patient were taken at the same point in time to assess whether stromal changes were limited to sites of disease. Multiple samples were examined over the course of a patient's illness to assess whether the stromal changes were modulated according to disease activity. There was a significant increase in tenascin expression and MVD in the sites of disease compared with uninvolved sites (p = 0.01 and p < 0.0001, respectively). In patients who responded to therapy, there was a decrease in the expression of tenascin (p = 0.0049) and MVD (p < 0.0001), and in those with disease progression there was an increase in the tenascin expression (p = 0.0050) and MVD (p < 0.0001). Our results suggest stromal changes are isolated to the sites of disease within patients, allowing targeted therapies to be developed. Further, stromal changes correlate with disease response over the course of the patient's disease. This new finding may have implications for the timing of anti-stromally directed therapies.

Development and validation of CALR mutation testing for clinical diagnosis.

OBJECTIVES: To validate a diagnostic assay for detecting CALR mutations in the clinical setting. METHODS: Traditional polymerase chain reaction (PCR) was performed on DNA previously extracted from 60 specimens (30 bone marrow aspirates [BMAs] and 30 peripheral blood [PB] samples) from 55 patients. Nearly all reported CALR mutations are insertions or deletions in exon 9. Therefore, we performed amplicon sizing by capillary electrophoresis and fragment length analysis (FLA) to determine mutation status. Mutations were confirmed by Sanger sequencing. RESULTS: Fourteen samples from 10 patients with JAK2 and MPL wild-type myeloproliferative neoplasms were positive for CALR mutation. Detected mutations included a 52-base pair (bp) deletion (n = 6), a 5-bp insertion (n = 2), a 31-bp deletion (n = 1), and a 61-bp deletion (n = 1). Sanger sequencing of 15 samples showed 100% concordance. Matched patient PB and BMA samples (n = 5) harbored identical mutations, and samples run multiple times (n = 8) showed 100% reproducibility. CONCLUSIONS: We conclude that CALR mutations may be quickly and accurately detected by FLA of PCR amplicons by capillary electrophoresis. These methods are routine procedures for most molecular laboratories and should allow for straightforward incorporation of the CALR assay into the clinical diagnostic testing menu.

Thoracic presentations of posttransplant lymphoproliferative disorders.

BACKGROUND: Posttransplant lymphoproliferative disorders (PTLDs) are rare complications following transplantation. Although organ-specific cases have been reported, primary presentation in the thoracic cavity has not been fully characterized. METHODS: Eleven cases of PTLD with a primary thoracic presentation were identified among 3,085 solid-organ transplant patients and 1,662 bone marrow transplant patients from 1990 to 2001. RESULTS: There were eight men and three women with a mean age of 49 years. Transplanted organs included lungs (three patients), kidneys (three patients), kidney/pancreas (two patients), allogeneic bone marrow (two patients), and heart (one patient). The time to presentation ranged from 1 to 97 months (median time, 8 months). Six patients developed PTLD within 1 year of undergoing transplantation. Pretransplant serology for Epstein-Barr virus (EBV) and cytomegalovirus was negative in 80% and 78% of cases, respectively. Radiographic evaluation revealed mediastinal adenopathy in 45% of patients, and pulmonary parenchymal lesions in 55%. Fifty-five percent of patients also had extrathoracic involvement. Diagnosis was achieved by CT-guided transthoracic needle biopsy in eight patients, and by open biopsy in three patients. Pathologic analysis revealed monomorphic PTLD (ie, diffuse large B-cell lymphoma) in seven patients, polymorphic PTLD in two patients, anaplastic large cell lymphoma in one patient, and Hodgkin lymphoma in one patient. Eighty-four percent of the specimens evaluated for EBV were determined to be positive by in situ hybridization and/or immunohistochemistry. All patients were initially treated with a reduction in immunosuppression therapy, and six patients (55%) received adjuvant chemotherapy. The overall mortality rate was 64%. Four patients died from complications of PTLD (kidney, two patients; heart, one patient; bone marrow, one patient), and three patients (all lung transplant recipients) died from rejection or infectious complications. The median interval from diagnosis to death was 13 months (range, 1 to 42 months). CONCLUSIONS: Thoracic PTLD can occur in any transplant patient and must be regarded as a potentially fatal complication in the immunosuppressed patient. Heart and lung allograft recipients have the worst prognosis because of the mortality that accompanies rejection with subtherapeutic immunosuppression therapy. Earlier diagnosis and improvements in immunosuppression and chemotherapy may improve survival for these inherently high-risk patients.

Flow cytometry in the differential diagnosis of lymphocyte-rich thymoma from precursor T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma.

We compared the antigen expression profile of thymocytes in lymphocyte-rich thymoma with that of precursor T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma (T-cell ALL/LBL) cells using 4-colorflow cytometry. In all 15 thymoma cases, the thymocytes demonstrated 3 distinct subpopulations. The least mature cells (double-negative) expressed low-density CD2 and CD5, high-density CD7, CD10, CD34, and heterogeneous CD4 and CD8. They had the lowest density CD45 expression and were surface CD3-. The immature cells (double-positive) expressed CD2, CD5, CD7, CD4, CD8, heterogeneous surface CD3, and intermediate-density CD45. They were CD10- and CD34-. The mature cells (single-positive) expressed CD2, surface CD3, CD5, CD7, and CD4 or CD8. The heterogeneous expression of surface CD3, CD4, and CD8 also created a characteristic smearing pattern for these antigens. In all 15 T-cell ALL/LBL cases, the lymphoblasts formed a tight cluster without discrete subpopulations or smearing pattern. Of 5 double-negative cases, 4 demonstrated loss of CD2, CD10, or CD34 expression. Of 7 double-positive cases, 5 showed complete loss of surface CD3, CD2, and/or CD5; 4 were CD10+; and 2 were CD34+. Of 3 single-positive cases, 2 showed loss of CD2 and/or aberrant expression of CD34. Analysis of antigen expression pattern, the presence or absence of T cell-associated antigen deletion, and the expression of CD10 and CD34 by 4-color flow cytometry can help differentiate thymoma from T-cell ALL/LBL.

Immunophenotypic analysis of anaplastic large cell lymphoma by flow cytometry.

We studied the antigen expression profiles of 19 anaplastic large cell lymphoma (ALCL) cases by multiparameter flow cytometry. The neoplastic cells expressed CD45, HLA-DR, and CD30 in all cases. At least 1 T cell-associated antigen was expressed in each case (CD2, 12/17 [71%]; CD4, 12/19 [63%]; CD3, 6/19 [32%]; CD7, 6/19 [32%]; CD5, 5/19 [26%]; CD8, 4/19 [21%]). CD25 was expressed in 14 (88%) of 16 cases. CD13 was expressed unexpectedly in 8 (47%) of 17 cases. One CD13+ ALCL also was positive for CD33 and 2 others for CD15, CD19, CD20, CD22, CD14, and CD36 were not expressed. Anaplastic lymphoma kinase protein was detected in about 33% (3/9) of ALCLs examined by flow cytometric immunophenotyping (FCI); expression was validated by immunohistochemical analysis. Of 19 ALCL cases, 12 were diagnosed solely based on FCI findings in conjunction with morphologic evaluation of body fluid (1 case), fine-needle aspirate (3 cases), or excisional biopsy specimen (8 cases). The diagnoses of the remaining 7 cases were suggested strongly by FCI and confirmed by immunohistochemical analysis. FCI is useful to aid in diagnosis of ALCL, particularly along with fine-needle aspiration evaluation. ALCL with aberrant expression of myeloid antigens should not be mistaken for extramedullary myeloid tumor.

Multiple myeloma in association with sarcoidosis.

The association of sarcoidosis with Hodgkin disease and non-Hodgkin lymphoma is well known. However, multiple myeloma also can occur rarely in association with sarcoidosis. We describe a patient with sarcoidosis who subsequently developed multiple myeloma. The patient was a 49-year-old woman with a 4-year history of severe, chronic, active sarcoidosis involving her lungs, lymph nodes, eyes, and bone marrow. During the initial clinical workup, a serum monoclonal paraprotein was detected and bone marrow examination revealed a slight increase in plasma cells (4%), in addition to noncaseating granulomas. Thus, the diagnoses of monoclonal gammopathy of undetermined significance and sarcoidosis were established simultaneously. She sought medical attention for her current illness when she developed low back pain and weakness of her lower extremities. Serum protein electrophoresis and immunofixation revealed a monoclonal paraprotein, immunoglobulin (Ig) G kappa type, and quantification revealed an IgG level of 46.67 g/L (normal, 5.88--15.73 g/L). Bone marrow aspiration and biopsy revealed multiple myeloma and sarcoidosis. Including this patient, 11 cases of sarcoidosis and multiple myeloma have been reported to date, including 3 patients with monoclonal gammopathy of undetermined significance preceding the onset of multiple myeloma. In this case, as in most of the cases reported previously, sarcoidosis preceded the development of multiple myeloma.

T-cell-rich B-cell lymphoma presenting in the spleen: a clinicopathologic analysis of 3 cases.

We review the clinical, pathologic, and molecular genetic features of 3 splenic T-cell-rich B-cell lymphomas and discuss their differential diagnosis. All patients presented with symptomatic splenomegaly and underwent diagnostic/therapeutic splenectomy. Microscopically, the spleen in all cases showed a micronodular proliferation of lymphoid cells. A proportion of the nodules demonstrated central hyalinization or sclerosis. There was also an exuberant extramedullary hematopoiesis. On immunohistochemical stain, the nodules consisted predominantly of small T cells with scattered large atypical B cells. The clonal nature of the atypical B cells was confirmed by polymerase chain reaction assays for immunoglobulin heavy-chain gene rearrangement. In the H&E sections, the differential diagnoses included Hodgkin's lymphoma, follicular lymphoma, peripheral T-cell lymphoma, and nonneoplastic granulomatous process. The presence of exuberant extramedullary hematopoiesis also raised the possibility of a chronic myeloproliferative disorder. The combined morphologic, immunohistochemical, and molecular genetic data are essential for a correct diagnosis of splenic T-cell-rich B-cell lymphoma.

A rare presentation of myocardial plasmacytoma assessed by FDG PET/CT.

We describe a rare case of myocardial plasmacytoma staged and followed up with FDG PET/CT. A 72-year-old man was incidentally identified with a right ventricular apical mass, which was pathologically confirmed to be a plasmacytoma. A pre-treatment FDG PET/CT scan subsequently showed lesions not only in the right ventricle but also in the bones and mediastinal lymph nodes, which led to the change in treatment plan. Post-therapy PET scan revealed good response. This case demonstrates the value of FDG PET/CT in accurately staging unusually presented plasmacytoma and in monitoring response to treatment.

Molecular Pathology of Malignant Lymphoma.

This review focuses on practical uses of molecular testing in mature B-cell and T-cell lymphomas with a focus on those lymphomas in which molecular testing is common. Clinical findings, histology, and biomarkers, as well as diagnostic and prognostic predictive value and practical applications of molecular testing for mature B- and T-cell lymphomas are presented.

The genetic landscape of mutations in Burkitt lymphoma.

Burkitt lymphoma is characterized by deregulation of MYC, but the contribution of other genetic mutations to the disease is largely unknown. Here, we describe the first completely sequenced genome from a Burkitt lymphoma tumor and germline DNA from the same affected individual. We further sequenced the exomes of 59 Burkitt lymphoma tumors and compared them to sequenced exomes from 94 diffuse large B-cell lymphoma (DLBCL) tumors. We identified 70 genes that were recurrently mutated in Burkitt lymphomas, including ID3, GNA13, RET, PIK3R1 and the SWI/SNF genes ARID1A and SMARCA4. Our data implicate a number of genes in cancer for the first time, including CCT6B, SALL3, FTCD and PC. ID3 mutations occurred in 34% of Burkitt lymphomas and not in DLBCLs. We show experimentally that ID3 mutations promote cell cycle progression and proliferation. Our work thus elucidates commonly occurring gene-coding mutations in Burkitt lymphoma and implicates ID3 as a new tumor suppressor gene.

Peripheral blood monitoring of chronic myeloid leukemia during treatment with imatinib, second-line agents, and beyond.

BACKGROUND: The current study was conducted to compare simultaneously obtained bone marrow (BM) cytogenetics (CTG), peripheral blood (PB) and BM fluorescence in situ hybridization (FISH), and quantitative real-time polymerase chain reaction (Q-PCR) for BCR-ABL1 in monitoring response to treatment with tyrosine kinase inhibitors and homoharringtonine (HHT) in patients with chronic myeloid leukemia (CML). METHODS: PB and BM FISH (n = 112 samples) and/or Q-PCR (n = 132 samples) for BCR-ABL1 were simultaneously obtained in 70 patients with Philadelphia chromosome-positive (Ph+) CML in chronic (68%), accelerated (16%), and blast phase (16%) before the initiation of therapy and during the course of treatment with imatinib (IM) (n = 40 patients), dasatinib (n = 20 patients), nilotinib (n = 4 patients), bosutinib (n = 18 patients), or HHT (n = 4 patients) for patients with newly diagnosed (n = 13 patients), IM-sensitive (n = 34 patients), IM-resistant (n = 30 patients), or IM-intolerant (n = 9 patients) disease. Eighteen patients were found to have Ph+ variants or karyotypic abnormalities in addition to the Ph+. RESULTS: Excellent correlations (r) were observed between PB and BM FISH (r = 0.95) and PB and BM Q-PCR (r = 0.87), as well as BM CTG and PB FISH (r = 0.89) and PB Q-PCR (r = 0.82). This correlation was not affected by the presence of the Ph+ variant or additional chromosomal abnormalities, the presence of ABL1 kinase domain mutations, phase of the disease, or treatment. CONCLUSIONS: PB FISH and Q-PCR appear to be reliable methods with which to monitor response to modern therapy in patients with all phases of CML.

Gene patents: perspectives from the clinical laboratory.

Patents involving human genes, human genetic material, and genotype-phenotype correlations are a reality and are increasingly having a negative effect on the clinical molecular diagnostic laboratory and on patient care. Specifically, gene patents and exclusive licensing of diagnostic testing has a detrimental effect on the quality of laboratory testing, the cost of testing, turnaround time, coordination of care, patient access to testing and the ability to confirm testing at a separate laboratory. In this article, gene patents are discussed from the perspective of a medical director of a molecular diagnostics laboratory, and the effect of such patents on clinical laboratory practice is examined.

A novel flow cytometric antibody panel for distinguishing Burkitt lymphoma from CD10+ diffuse large B-cell lymphoma.

Rapid and accurate differential diagnosis between Burkitt lymphoma (BL) and CD10+ diffuse large B-cell lymphoma (DLBCL) is imperative because their treatment differs. Recent studies have characterized several antigens differentially expressed in these 2 types of lymphoma. Our goal was to determine whether use of these markers would aid in the differential diagnosis of BL vs CD10+ DLBCL by flow cytometric immunophenotyping (FCI). Twenty-three cases of CD10+ B-cell lymphomas with available cryopreserved samples were identified (13 BL and 10 CD10+ DLBCL). Multiparameter FCI was performed using the following antibodies: CD18, CD20, CD43, CD44, and CD54 and isotype controls. Expression of CD44 and CD54 was detected at a significantly lower level in BL compared with CD10+ DLBCL (P = .001 and P = .01, respectively). There was not a significant difference in expression of CD18 and CD43. Our data show that expression of CD44 and CD54 differs significantly between BL and CD10+ DLBCL.