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B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL) (intermediate DLBCL/BL), is a heterogeneous group with some features resembling DLBCL and others resembling BL. Here, we report a case of intermediate DLBCL/BL in a Korean child. A 2-yr-old male was admitted for evaluation and management of left hip pain. Immunohistochemistry of a biopsy of the femur neck revealed tumor cells positive for CD20, CD10, BCL2, BCL6, and Ki67. A bone marrow (BM) aspirate smear revealed that 49.3% of all nucleated cells were abnormal lymphoid cells, composed of large- and medium-sized cells. Immunophenotyping of the neoplastic cells revealed positivity for CD19, CD10, CD20, and sIg lambda and negativity for CD34, Tdt, and myeloperoxidase (MPO). Cytogenetic and FISH analyses showed a complex karyotype, including t(8;14)(q24.1;q32) and IGH-MYC fusion. Intensive chemotherapy was initiated, including prednisone, vincristine, L-asparaginase, daunorubicin, and central nervous system prophylaxis with intrathecal methotrexate (MTX) and cytarabine. One month after the initial diagnosis, BM examination revealed the persistent of abnormal lymphoid cells; cerebrospinal fluid cytology, including cytospin, showed atypical lymphoid cells. The patient was treated again with cyclophosphamide, vincristine, prednisone, adriamycin, MTX, and intrathecal MTX and cytarabine. The patient died of sepsis 5 months after the second round of chemotherapy.

Lymphomas of the gall bladder and extrahepatic bile ducts are exceedingly rare. We present the clinicopathological features of 19 cases from our files; 14 patients had primary lymphoma (13 involving gall bladder and one involving common hepatic duct), while five had systemic lymphoma on further work-up. Most patients presented with symptoms mimicking cholecystitis. The most common primary lymphoma types were diffuse large B-cell lymphoma (DLBCL), extranodal marginal zone lymphoma (EMZL), B-lymphoblastic lymphoma (B-LBL) and follicular lymphoma (FL). Two cases had features of lymphomatous polyposis, one a case of FL and the second a case of mantle cell lymphoma (MCL), with disease limited to the mantle zones, so-called in situ MCL. Other rare lymphoma subtypes not previously described in this site included the extracavitary variant of primary effusion lymphoma (PEL) and plasmablastic lymphoma (PBL). Patients with DLBCL and EMZL were older (mean age 75.8 years) than those with other subtypes (mean age 47 years) and more likely to have gallstones (60% vs. 12.5%). A comprehensive literature review revealed 36 primary gall bladder and 16 primary extrahepatic bile duct lymphomas. When compared to primary gall bladder lymphomas, those involving the extrahepatic bile ducts present at a younger age (47 years vs. 63 years) usually with obstructive jaundice, and are less often associated with gallstones (17% vs. 50%) or regional lymph node involvement (6% vs. 31%). In conclusion, primary lymphomas of the gall bladder and extrahepatic bile ducts show a broad spectrum of disease types, but in many respects mirror the spectrum of primary lymphomas of the gastrointestinal tract.

Sixty-four cases of malignant lymphoma involving the liver were examined. Of these, 20 cases were histologically confirmed to be primary hepatic B-cell lymphoma. Twelve of these 20 cases were diffuse large B-cell lymphoma (DLBCL) and eight cases were mucosa-associated lymphoid tissue (MALT) lymphoma. Of the 12 cases of DLBCL, six were immunohistologically positive for CD10 and/or Bcl6 (indicating a germinal center phenotype), six were positive for Bcl2, and five were positive for CD25. Eight of the 12 DLBCL cases (66.7%) and two of the eight MALT lymphoma cases (25%) had serum anti-hepatitis C virus (HCV) antibodies and HCV RNA. The incidence of HCV infection was significantly higher in the hepatic DLBCL cases than in systemic intravascular large B-cell cases with liver involvement (one of 11 cases, 9.1%) and T/NK-cell lymphoma cases (one of 19 cases, 5.3%) (p < 0.01 for both). Two hepatic DLBCL cases (16.7%) had rheumatoid arthritis treated with methotrexate, and four MALT lymphoma cases (50%) had Sjögren’s syndrome, primary biliary cirrhosis, or autoimmune hepatitis; one case in each of these two groups was complicated by chronic HCV-seropositive hepatitis. Although primary hepatic lymphoma is rare, persistent inflammatory processes associated with HCV infection or autoimmune disease may play independent roles in the lymphomagenesis of hepatic B cells.

Follicular lymphoma (FL) is a neoplasm originating from germinal centre cells, corresponding to 25–40% of non‐Hodgkin's lymphomas. Transformation into diffuse large B cell lymphoma (DLBCL) occurs in about one‐third of cases. CD5 is expressed in B‐chronic lymphoid leukaemia/small lymphocytic lymphoma and mantle cell lymphoma, but can rarely be expressed in conjunction with CD10 in well‐documented cases of FL. In this report one case of grade 1 FL is described, which transformed into a DLBCL 6 months after initial diagnosis, with both tumours expressing CD5. In both specimens, neoplastic cells were strongly positive for CD20, CD79a, bcl‐2, bcl‐6 and CD5 in virtually all cells. CD10 was strongly positive in initial specimens and weakly positive in the DLBCL. Investigation using the PCR confirmed the derivation of the DLBCL from the FL as they presented the same immunoglobulin heavy chain gene rearrangement and the same BCL2‐JH break point.

Mantle cell lymphoma, blastoid variant (B-MCL), is a very rare type of non-Hodgkin's lymphoma exhibiting an aggressive clinical course. We describe a case of B-MCL showing generalized lymphadenopathy and leukemic conversion in a 62-yr-old man. The case was diagnosed and subclassified as B-MCL on the basis of cyto-morphology and immunophenotype. Microscopic examination of the peripheral blood (PB) showed a spectrum of cells ranging from small mature lymphocytes to medium- and large-sized lymphocytes with blast-like chromatin and prominent nucleoli. The lymphoma cells were monoclonal B cells with moderately intense surface IgM. They were CD5 positive, cyclin D1 positive, CD10 negative, and CD23 negative. The flow cytometric immunophenotyping and DNA ploidy analysis of the PB and material obtained by aspiration cytology supported the diagnosis of B-MCL. These findings underline the utility of aspiration cytology in diagnosing B-MCL when cytomorphologic examination is combined with flow cytometric analysis of immuno-phenotype and demonstration of proliferation markers.

Primary bone marrow presentation of diffuse large B-cell lymphoma (DLBCL) is unusual, and appreciation of the diffuse growth pattern may be difficult in cases with low-level involvement. In particular, subtle sinusoidal and interstitial bone marrow involvement and morphologic overlap of the tumor cells with pronormoblasts may result initially in a missed diagnosis. We describe the clinicopathologic features of 13 cases of morphologically subtle DLBCL involving the bone marrow, which were only identified with the aid of immunohistochemistry. The overwhelming majority of cases (12/13, 92%) presented with cytopenias, and 5 of 7 cases, with available information, had splenomegaly. The morphology of the tumor cells in the aspirate smears overlapped with pronormoblasts (immature erythroid precursors) in 12 of 13 cases. Similarly, in histologic sections, the tumor cells in virtually all cases (12/13) demonstrated round nuclear contours and oblong nucleoli, mimicking pronormoblasts. A CD20 immunohistochemical stain was essential in identifying the neoplastic infiltrate in all cases. The majority of cases (73%, 10/13) showed low-level bone marrow involvement by lymphoma, 10% or less. CD20 immunohistochemistry highlighted individually dispersed and small clusters of large lymphoid cells in a sinusoidal and/or interstitial growth pattern. Most of the cases that were assessed showed a non-germinal center phenotype (CD10-, BCL6-/+, IRF4/MUM1+). There was an aggressive disease course with a median overall survival of 6 months. We would recommend performing a CD20 immunostain in patients who present with unexplained cytopenias and/or splenomegaly. Further investigation is warranted to better describe the features of this unique and aggressive variant of DLBCL.

Aggressive B-cell lymphoma (BCL) comprises a heterogeneous group of malignancies, including diffuse large B-cell lymphoma (DLBCL), Burkitt lymphoma, and mantle cell lymphoma (MCL). DLBCL, with its 3 subtypes, is the most common type of lymphoma. Advances in chemoimmunotherapy have substantially improved disease control. However, depending on the subtype, patients with DLBCL still exhibit substantially different survival rates. In MCL, a mature B-cell lymphoma, the addition of rituximab to conventional chemotherapy regimens has increased response rates, but not survival. Burkitt lymphoma, the most aggressive BCL, is characterized by a high proliferative index and requires more intensive chemotherapy regimens than DLBCL. Hence, there is a need for more effective therapies for all three diseases. Increased understanding of the molecular features of aggressive BCL has led to the development of a range of novel therapies, many of which target the tumor in a tailored manner and are summarized in this paper.

Introduction

The expression of smooth muscle actin (SMA) and s100p has been identified on an aggressive retro-orbital diffuse large B cell lymphoma (DLBCL) [1].

Aim

To assess the prognostic significance of immunohistochemical (IHC) expression of SMA and s100p on DLBCL.

Materials and methods

Twenty nine cases diagnosed as DLBCL were first classified into germinal centre (GC) B cell like and non GC origin either activated B cells (ABC) or type 3 based on their immunoreactivity for CD10, bcl-6 and Mum-1. Bcl-2 and MIB-1 as adverse prognostic factors were assessed. SMA and s100p were evaluated and correlated with patients' clinicopathological characteristics.

Results

Eleven cases (37.93%) positive for CD10 and/or bcl-6 were classified as GC B cell like subtype, 7 cases positive only for Mum-1 as ABC subtype (24.14%), and 11 cases double positive or negative for bcl-6 and Mum-1 were considered as type 3 (37.93%). Nuclear and cytoplasmic SMA and s100p were expressed in 58.62% and 51.72% of cases respectively and were strongly associated with the non GC like phenotype (p < 0.001 for SMA and p < 0.01 for s100p). SMA and s100p were strongly related to each other (p < 0.001). SMA was closely associated with bcl-2 and MIB-1 (p < 0.01 and p < 0.025 respectively), while s100p was only associated with bcl-2 (p < 0.05).

Conclusion

SMA and s100p are expressed on non GC DLBCL and appear to be adverse prognostic factors. Future large studies evaluating their significance will be valuable to assess the different subgroups in clinical context. Lastly, this expression may lead to misdiagnosis of non hematopoeitic neoplasm if lymphoid markers are not included in the IHC panel.

Diffuse large B-cell lymphoma (DLBCL) constitutes most primary central nervous system (CNS) lymphoma (PCNSL), whereas T-cell, low-grade and Burkitt’s lymphomas (BL) are rarely encountered. Due to the paucity of cases, little is known about the clinical features and treatment outcomes of PCNSL other than DLBCL. The objective of this study was to describe the clinical characteristics and outcomes for patients with PCNSL other than DLBCL. Fifteen patients, newly diagnosed with PCNSLs other than DLBCL between 2000 and 2010, were included. The male to female ratio was 0.67:1 with a median age of diagnosis of 31 years (range 18–59). Pathologic distributions were as follows: peripheral T-cell lymphoma (PTCL; n = 7), marginal zone B-cell lymphoma (MZBCL; n = 1), lymphoplasmacytic lymphoma (LPL; n = 2), Burkitt’s lymphoma (n = 1), other unspecified (T-cell lineage, n = 2; B-cell lineage, n = 2). Thirteen patients (87%) showed Eastern Cooperative Oncology Group performance score (ECOG PS) 1–2. The remaining two were one PTCL patient and one Burkitt’s lymphoma patient. Of the nine patients with T-cell lymphoma, five (56%) had multifocal lesions, and one (20%) with LPL of the five patients with B-cell lymphoma showed a single lesion. Leptomeningeal lymphomatosis was identified in two patients (one with Burkitt’s lymphoma and one with unspecified B-cell lymphoma). Two patients (22%) with T-cell lymphoma died 7.7 and 23.3 months later, respectively, due to disease progression, despite HD-MTX-based therapy. Six patients with T-cell lymphoma (6/9, 66.7%) and four patients with low-grade B-cell lymphoma (4/5, 80%) achieved complete response and have survived without relapse (Table 3). One patient with Burkitt’s lymphoma showed poor clinical features with ECOG PS 3, deep structure, multifocal, and leptomeningeal lymphomatosis, and died 7.6 months after the initiation of treatment. In comparison with previously reported DLBCLs (median OS 6.4 years, 95% CI 3.7–9.1 years), T-cell lymphoma showed equivocal or favorable clinical outcomes and low-grade B-cell lymphomas, such as MZBCL and LPL, had a good prognosis. However, primary CNS Burkitt’s lymphoma presented poor clinical outcomes and showed a comparatively aggressive clinical course. In conclusion, primary CNS lymphoma other than DLBCL occurred more in younger patients and showed a generally good prognosis, except for Burkitt’s lymphoma. Further research on treatment strategies for Burkitt’s lymphoma is needed.

Breast lymphoma accounts for less than 1% of all non-Hodgkin's lymphomas (NHLs) and approximately 0.1% of all breast neoplasms. Most breast lymphomas are classified as diffuse large B cell or mucosa associated lymphoid tissue (MALT) lymphomas. The case of a 53 year old woman presenting with a breast mass and found to have mantle cell lymphoma is described. Core biopsy of the breast lesion showed a B cell NHL, probably of large cell type and of high grade. Morphological and immunophenotypic analysis of peripheral blood and bone marrow samples suggested a mantle cell lymphoma (MCL). This was confirmed by the detection of a t(11;14) in the bone marrow aspirate and breast tissue by polymerase chain reaction analysis. There have been no previous reports of an MCL presenting as a breast lump. Because a diagnosis of MCL has prognostic and therapeutic implications, this case highlights the need for an awareness of MCL presenting in this way, and the requirement for specialised investigations in its detection.

Key Words: mantle cell lymphoma • breast lymphoma • cyclin D1 • t(11;14)

Background

To describe a rare manifestation of mantle cell lymphoma (MCL) in conjunctiva, with clinical, hisologic, immunohistologic and genetic findings together with review of the Literature.

Case presentation

Most ocular adnexal lymphomas are extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT). A few cases of ocular adnexal mantle cell lymphomas have been reported in the literature. We present a case of mantle cell lymphoma presenting as right conjunctival mass of at least three months duration in a 64-year-old man. Histopathologic examination showed a proliferation of monomorphous small-to-medium-sized lymphoid cells with cleaved nuclei in the subconjunctiva. By immunohistochemistry, the infiltrate was positive for CD20, CD5, BCL-2, cyclin D1, and the transcription factor SOX11. Fluorescent in situ hybridization demonstrated the presence of IGH-CCND1 fusion indicating t(11;14).

Conclusion

A rigorous approach to initial diagnosis and staging of small cell lymphomas of the ocular adnexa is needed. The recognition of ocular MCL requires appropriate immunohistochemical staining and/or genetic confirmation to differentiate this rare form of presentation of MCL from other more frequent small cell lymphomas.

The utility of CD20 immunohistochemistry in the evaluation of staging bone marrow biopsies of newly diagnosed diffuse large B-cell lymphomas (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 five (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.

Background

Anaplastic lymphoma kinase-positive diffuse large B-cell lymphoma (ALK-DLBCL) is a rare lymphoma with several clinicopathological differences from ALK-positive anaplastic large cell lymphoma (ALCL). The latest WHO classification of lymphomas recognizes ALK-DLBCL as a separate entity.

Methods

A comprehensive comparison was made between the clinical and pathological features of the 4 cases reported and those found in an extensive literature search using MEDLINE through December 2008.

Results

In our series, three cases were adults and one was pediatric. Two cases had primary extranodal disease (multifocal bone and right nasal fossa). Stages were I (n = 1), II (n = 1), III (n = 1) and IV (n = 1). Two cases had increased LDH levels and three reported B symptoms. IPI scores were 0 (n = 1), 2 (n = 2) and 3 (n = 1). All cases exhibited plasmablastic morphology. By immunohistochemistry, cases were positive for cytoplasmic ALK, MUM1, CD45, and EMA; they marked negative for CD3, CD30 and CD20. Studies for EBV and HHV-8 were negative. The survival for the patients with stage I, II, III and IV were 13, 62, 72 and 11 months, respectively.

Conclusion

ALK-DLBCL is a distinct variant of DLBCL with plasmacytic differentiation, which is characterized by a bimodal age incidence curve, primarily nodal involvement, plasmablastic morphology, lack of expression of CD20, aggressive behavior and poor response to standard therapies, although some cases can have prolonged survival as the cases reported in this study. ALK-DLBCL does not seem associated to immunosuppression or the presence of EBV or HHV8. Further prospective studies are needed to optimize therapies for this entity.

The distinction between Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL), two types of mature aggressive B-cell lymphomas that require distinct treatments, can be difficult because of forms showing features intermediate between DLBCL and BL (here called BL/DLBCL). They can be discriminated by the presence of c-myc translocations characteristic of BL. However, these are not exclusive of BL and when present in DLBCL are associated with lower survival. In this study, we show that Epstein-Barr virus-induced gene 3 (EBI3) is differentially expressed among BL and DLBCL. Analysis of gene expression data from 502 cases of aggressive mature B-cell lymphomas available on Gene Expression Omnibus and immunohistochemical analysis of 184 cases of BL, BL/DLBCL or DLBCL, showed that EBI3 was not expressed in EBV-positive or -negative BL cases, whereas it was expressed by over 30% of tumoral cells in nearly 80% of DLBCL cases, independently of their subtypes. In addition, we show that c-myc overexpression represses EBI3 expression, and that DLBCL or BL/DLBCL cases with c-myc translocations have lower expression of EBI3. Thus, EBI3 immunohistochemistry could be useful to discriminate BL from DLBCL, and to identify cases of BL/DLBCL or DLBCL with potential c-myc translocations.

Primary bone marrow diffuse large B-cell lymphoma (DLBCL) is a rare type of extranodal lymphoma with poor prognosis. Here, we report a case of primary bone marrow DLBCL successfully treated with high-dose chemotherapy and rescued by in vivo rituximab-purged autologous stem cells. A 39-year-old woman visited our hospital because of anemia. Bone marrow examination revealed a large B-cell lymphoma invasion. An 18F-fluorodeoxyglucose positron emission tomography scan revealed disseminated bone marrow uptake without evidence of dissemination at other sites. These findings led to a diagnosis of primary bone marrow DLBCL. Our patient underwent R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) chemotherapy and achieved complete remission. Subsequently, she received high-dose chemotherapy with an in vivo rituximab-purged autologous stem cell transplant. Seven years have passed since the transplantation, and she remains in remission. This suggests that transplantation of an in vivo rituximab-purged autograft is a promising strategy for primary bone marrow DLBCL.

Post-transplantation lymphoproliferative disorders (PTLD) arise in the immunosuppressed and are frequently Epstein-Barr virus (EBV) associated. The most common PTLD histological sub-type is diffuse large B-cell lymphoma (EBV+DLBCL-PTLD). Restoration of EBV-specific T-cell immunity can induce EBV+DLBCL-PTLD regression. The most frequent B-cell lymphoma in the immunocompetent is also DLBCL. ‘EBV-positive DLBCL of the elderly’ (EBV+DLBCL) is a rare but well-recognized DLBCL entity that occurs in the overtly immunocompetent, that has an adverse outcome relative to EBV-negative DLBCL. Unlike PTLD (which is classified as viral latency III), literature suggests EBV+DLBCL is typically latency II, i.e. expression is limited to the immuno-subdominant EBNA1, LMP1 and LMP2 EBV-proteins. If correct, this would be a major impediment for T-cell immunotherapeutic strategies. Unexpectedly we observed EBV+DLBCL-PTLD and EBV+DLBCL both shared features consistent with type III EBV-latency, including expression of the immuno-dominant EBNA3A protein. Extensive analysis showed frequent polymorphisms in EB-NA1 and LMP1 functionally defined CD8+ T-cell epitope encoding regions, whereas EBNA3A polymorphisms were very rare making this an attractive immunotherapy target. As with EBV+DLBCL-PTLD, the antigen presenting machinery within lymphomatous nodes was intact. EBV+DLBCL express EBNA3A suggesting it is amenable to immunotherapeutic strategies.

Background

To evaluate the role of flow cytometric immunophenotyping (FCI) in diagnosis and characterization of lymphoma tissue specimens from Egyptian patients.

Methods

FCI using 2 and 3 color staining approaches, was performed on 50 fresh lymph nodes specimen from Cairo NCI patients with suspected lymphoma presenting with either localized or generalized lymphadenopathy.

FCI results were correlated with histopathologic as well as immunophenotypic[by immunohistochemistry (IHC)] findings.

Results

By FCI, cases were diagnosed as follows: 9(18%) reactive hyperplasia (RH), 32(64%) B-cell non-Hodgkin's lymphoma (B-NHL) [24 diffuse large (DLBCL), 2 follicular, 3 small lymphocytic, 2 mantle cell lymphoma and a case of T cell rich B cell lymphoma], 3 (6%) T cell NHL [2 peripheral T cell lymphoma and a case of anaplastic large cell lymphoma], 2(4%) Hodgkin's lymphoma (HL) while 4 (8%) were non-lymphomatous tumors (NLT). Light chain restriction (LCR) was detected in the 32 FCI diagnosed B-NHL. The overall concordance between FCI versus histopathology and IHC was 88%. The sensitivity and specificity of FCI in diagnosis of NHL was 94.9% and 100% respectively; in HL they were 40% and 100% respectively and in NLT, both sensitivity and specificity were 100% while for RH were 100% and 89.1% respectively.

Conclusion

FCI is a sensitive and specific method in diagnosis and classification of NHL as well as in detection of monoclonality. False negative results could be due to the presence of heterogeneous populations of lymphocytes in special types of lymphoma.

Gene expression profiling of diffuse large B-cell lymphoma (DLBCL) has revealed biologically and prognostically distinct subgroups: germinal center B-cell-like (GCB), activated B-cell-like (ABC) and primary mediastinal (PM) DLBCL. The BCL6 gene is often translocated and/or mutated in DLBCL. Therefore, we examined the BCL6 molecular alterations in these DLBCL subgroups, and their impact on BCL6 expression and BCL6 target gene repression. BCL6 translocations at the major breakpoint region (MBR) were detected in 25 (18.8%) of 133 DLBCL cases, with a higher frequency in the PM (33%) and ABC (24%) subgroups than in the GCB (10%) subgroup. Translocations at the alternative breakpoint region (ABR) were detected in five (6.4%) of 78 DLBCL cases, with three cases in ABC and one case each in the GCB and the unclassifiable subgroups. The translocated cases involved IgH and non-IgH partners in about equal frequency and were not associated with different levels of BCL6 mRNA and protein expression. BCL6 mutations were detected in 61% of DLBCL cases, with a significantly higher frequency in the GCB and PM subgroups (> 70%) than in the ABC subgroup (44%). Exon-1 mutations were mostly observed in the GCB subgroup. The repression of known BCL6 target genes correlated with the level of BCL6 mRNA and protein expression in GCB and ABC subgroups but not with BCL6 translocation and intronic mutations. No clear inverse correlation between BCL6 expression and p53 expression was observed. Patients with higher BCL6 mRNA or protein expression had a significantly better overall survival. The biological role of BCL6 in translocated cases where repression of known target genes is not demonstrated is intriguing and warrants further investigation.

The metastasis-suppressing role of the nm23 gene in the metastatic spread of malignant tumor is still debated. We examined the nm23-H1 protein expression and gene mutation in non-Hodgkin's lymphomas to compare with the clinicopathologic parameters. The expression of nm23-H1 protein was immunohistochemically examined in 150 cases of non-Hodgkin's lymphomas; 85 diffuse large B cell lymphomas (DLBCL), 18 marginal zone B cell lymphomas (MZL), 3 mantle cell lymphomas, 25 peripheral T cell lymphomas, not otherwise specified (TCLNOS), and 19 NK/T cell lymphomas (NK/T). Eighty-one cases (58 DLBCL, 6 MZL, 4 TCLNOS, and 13 NK/T) were studied for nm23-H1 gene mutation in exon 1 to 5. The high expression of nm23-H1 protein was associated with the high IPI score (p=0.019) and the low survival rate of the patients (p=0.0039). The gene mutation of nm23-H1 was detected in 10.3% of DLBCL and 30.7% of NK/T; but none in MZL and TCLNOS. The mutation was found in exon 1 in 5 cases, exon 2 in two cases, exon 4 in one case and both exon 1 and 2 in two cases. Our results suggest that the expression of nm23-H1 protein can be used as a poor prognostic marker in non-Hodgkin's lymphomas, and the mutational change of gene may operate in the lymphomagenesis.

Background

Gastrointestinal (GI) lymphomas are very common types of extranodal lymphomas, and we hypothesize there are regional differences in subtype, distribution in the GI tract, and epidemiological features among the different populations.

Methods

We retrospectively evaluated the clinical, molecular and histologic features of North American primary and secondary GI lymphomas diagnosed from 2000–2009 seen at our institution. We utilized immunohistochemistry and fluorescence in situ hybridization to further evaluate a subset of the gastric lymphomas.

Results

Extranodal marginal zone lymphomas of mucosal associated lymphoid tissue (MALTs) and diffuse large B cell lymphomas (DLBCLs) were the most common subtypes of GI lymphomas. Select gastric DLBCLs (N = 6) and MALTs (N = 13) were further examined for API2-MALT1 and IGH translocations, and P16 and P53 protein expression. Gastric MALTs showed frequent API2-MALT1 (38%) but not IGH translocations (0%), and the DLBCLs showed neither translocation. Expression of P16 and P53 proteins and the proliferative index were compared between high grade gastric lymphomas (gastric DLBCLs) and low grade gastric lymphomas (gastric MALTs). P53 overexpression (P = 0.008) and a high proliferation index [Ki-67] (P = 0.00042) were significantly associated with gastric DLBCL, but no statistically significant difference was observed in P16 expression (p = 0.108) between gastric DLBCL and gastric MALT.

Conclusion

Our study revealed that GI lymphomas from a Central-Midwestern North American population showed differences and similarities to non-North American cohorts. In addition, API2-MALT1, P16 and P53 abnormalities occurred frequently in gastric lymphomas from this North American population.

Virtual slides

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1415505838687793

The chromosomal translocation (11;14)(q13;q32) rearranging the locus for cyclin D1 (CCND1) to that of the immunoglobulin heavy chain (IGH) can be found in virtually all cases of mantle cell lymphoma (MCL), while other CCND1 translocations are extremely rare. As CCND1 overexpression and activation is a hallmark of MCL it is regarded as a central biological mechanism in the development and maintenance of this disease.

Here we present a patient initially diagnosed with chronic lymphocytic leukemia (CLL) where chromosome banding analysis revealed, among other aberrations, a translocation (11;22)(q13;q11.2). We show by fluorescence in situ hybridization (FISH) analysis that on chromosome 22 the immunoglobulin light chain lambda (IGL) is involved in this cytogenetic aberration. Additionally, we demonstrate the resulting overexpression of CCND1 on the RNA and protein level, thereby consolidating the new diagnosis of a MCL-like B-cell neoplasia. Summing up, we described a rare case of t(11;22)(q13;q11.2) in a MCL-like neoplasia and showed that this aberration leads to an overexpression of CCND1 which is regarded as a key biological feature in MCL. This case underlines the importance of cytogenetic analyses especially in atypical cases of B cell lymphomas.

Mantle cell lymphomas (MCL), characterized by the t(11;14)(q13;q32), frequently carry secondary genetic alterations such as deletions in chromosome 17p involving the TP53 locus. Given that the association between TP53-deletions and concurrent mutations of the remaining allele is weak and based on our recent report that the Hypermethylated in Cancer 1 (HIC1) gene, that is located telomeric to the TP53 gene, may be targeted by deletions in 17p in diffuse large B-cell lymphoma (DLBCL), we investigated whether HIC1 inactivations might also occur in MCL. Monoallelic deletions of the TP53 locus were detected in 18 out of 59 MCL (31%), while overexpression of p53 protein occurred in only 8 out of 18 of these MCL (44%). In TP53-deleted MCL, the HIC1 gene locus was co-deleted in 11 out of 18 cases (61%). However, neither TP53 nor HIC1 deletions did affect survival of MCL patients. In most analyzed cases, no hypermethylation of the HIC1 exon 1A promoter was observed (17 out of 20, 85%). However, in MCL cell lines without HIC1-hypermethylation, the mRNA expression levels of HIC1 were nevertheless significantly reduced, when compared to reactive lymph node specimens, pointing to the occurrence of mechanisms other than epigenetic or genetic events for the inactivation of HIC1 in this entity.

Background

Primary Sjögren's syndrome (SS) is associated with an increased frequency of non‐Hodgkin's lymphomas (NHLs), mainly of low histological grade. However, aggressive diffuse large B cell lymphomas (DLBCL) characterised by poor treatment outcome can also be encountered in SS. It has recently been shown that rituxan has significant therapeutic activity in this type of lymphoma.

Objective

To evaluate the efficacy of CHOP chemotherapy (cyclophosphamide, doxorubicin, vincristine, prednisone) in combination with rituxan in SS patients with DLBCL, and to determine the outcome in such patients.

Methods

In an open, single case trial, six SS patients with DLBCL were assigned to receive eight cycles of CHOP every three weeks plus rituxan given on day 1 of each cycle. In a retrospective study, conducted by the European Concerted Action for SS, nine cases were diagnosed as DLBCL, all of whom had been treated with CHOP alone. These patients were used as historical controls.

Results

The difference in the overall survival between the two treatment groups was significant. The group treated with rituxan plus CHOP had a 100% two year overall survival rate, while the historical controls had only a 37% survival rate. Extraglandular manifestations serving as predictors for lymphoma development such as palpable purpura and peripheral neuropathy disappeared. The remission of these signs was accompanied by a decrease in both circulating monoclonal cryoglobulins and rheumatoid factor activity and an increase in C4 levels. Clinically relevant toxicity was not detected.

Conclusions

The addition of rituxan to standard CHOP chemotherapy results in improved treatment outcome in SS patients with aggressive DLBCL, without increasing toxicity.

Background

Epigenetic inactivation of tumor suppressor genes (TSG) by promoter CpG island hypermethylation is a hallmark of cancer. To assay its extent in human lymphoma, methylation of 24 TSG was analyzed in lymphoma-derived cell lines as well as in patient samples.

Methods

We screened for TSG methylation using methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) in 40 lymphoma-derived cell lines representing anaplastic large cell lymphoma, Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), Hodgkin lymphoma and mantle cell lymphoma (MCL) as well as in 50 primary lymphoma samples. The methylation status of differentially methylated CD44 was verified by methylation-specific PCR and bisulfite sequencing. Gene expression of CD44 and its reactivation by DNA demethylation was determined by quantitative real-time PCR and on the protein level by flow cytometry. Induction of apoptosis by anti-CD44 antibody was analyzed by annexin-V/PI staining and flow cytometry.

Results

On average 8 ± 2.8 of 24 TSG were methylated per lymphoma cell line and 2.4 ± 2 of 24 TSG in primary lymphomas, whereas 0/24 TSG were methylated in tonsils and blood mononuclear cells from healthy donors. Notably, we identified that CD44 was hypermethylated and transcriptionally silenced in all BL and most FL and DLBCL cell lines, but was usually unmethylated and expressed in MCL cell lines. Concordant results were obtained from primary lymphoma material: CD44 was not methylated in MCL patients (0/11) whereas CD44 was frequently hypermethylated in BL patients (18/29). In cell lines with CD44 hypermethylation, expression was re-inducible at mRNA and protein levels by treatment with the DNA demethylating agent 5-Aza-2'-deoxycytidine, confirming epigenetic regulation of CD44. CD44 ligation assays with a monoclonal anti-CD44 antibody showed that CD44 can mediate apoptosis in CD44+ lymphoma cells. CD44 hypermethylated, CD44- lymphoma cell lines were consistently resistant towards anti-CD44 induced apoptosis.

Conclusion

Our data show that CD44 is epigenetically regulated in lymphoma and undergoes de novo methylation in distinct lymphoma subtypes like BL. Thus CD44 may be a promising new epigenetic marker for diagnosis and a potential therapeutic target for the treatment of specific lymphoma subtypes.

Background

The International Prognostic Index (IPI) is used to determine prognosis in diffuse large B-cell lymphoma (DLBCL). One of the determinants of IPI is the stage of disease with bone marrow involvement being classified as stage IV. For the IPI, involvement on bone marrow is traditionally defined on the basis of histology with ancillary investigations used only in difficult cases to aid histological diagnosis. This study aimed to determine the effect of the routine use of flow cytometry, immunohistochemistry and molecular studies in bone marrow staging upon the IPI.

Results

Bone marrow trephines of 156 histologically proven DLBCL cases at initial diagnosis were assessed on routine histology, and immunohistochemistry using two T-cell markers (CD45RO and CD3), two B-cell markers (CD20 and CD79a) and kappa and lambda light chains. Raw flow cytometry data on all samples were reanalysed and reinterpreted blindly. DNA extracted from archived paraffin-embedded trephine biopsy samples was used for immunoglobulin heavy chain and light chain gene rearrangement analysis. Using immunophenotyping (flow cytometry and immunohistochemistry), 30 (19.2%) cases were upstaged to stage IV. A further 8 (5.1%) cases were upstaged using molecular studies. A change in IPI was noted in 18 cases (11.5%) on immunophenotyping alone, and 22 (14.1%) cases on immunophenotyping and molecular testing. Comparison of two revised IPI models, 1) using immunophenotyping alone, and 2) using immunophenotyping with molecular studies, was performed with baseline IPI using a Cox regression model. It showed that the revised IPI model using immunophenotyping provides the best differentiation between the IPI categories.

Conclusion

Improved bone marrow staging using flow cytometry and immunohistochemistry improves the predictive value of the IPI in patients with DLBCL and should be performed routinely in all cases.