Flow cytometric detection and quantification of CD56 (neural cell adhesion molecule, NCAM) expression in diffuse large B cell lymphomas and review of the literature

Stacchini A, Barreca A, Demurtas A, Aliberti S, di Celle P F & Novero D
(2012) Histopathology  60, 452–459
Flow cytometric detection and quantification of CD56 (neural cell adhesion molecule, NCAM) expression in diffuse large B cell lymphomas and review of the literature Aim: To report unusual CD56 (neural cell adhesion molecule, NCAM) expression on diffuse large B cell lymphoma (DLBCL). Methods and results: CD56 expression was first detected and quantified on tissues obtained from five cases of DLBCL by flow cytometry (FC), then confirmed by immunohistochemistry. The CD56 expression pattern was heterogeneous among the cases [the molecular equivalent of soluble fluorochrome (MESF) level ranged from 2214 to 133 466]. All were CD10 and Bcl‐6 positive, suggesting their germinal centre origin; one was also CD5 positive. An extranodal presentation occurred in three of five cases. Conclusions: CD56 expression in B cell lymphoma is a rare occurrence. FC is able to identify aberrant immunophenotypes that can be useful in the identification and monitoring of B cell lymphoma subtypes. The presence of CD56 reported by the literature on certain DLBCL with extranodal presentation might be related to mechanisms involved in growth and expansion.     

Clinical features of diffuse large B‐cell lymphoma with polyploidy

Polyploidy, defined as more than two sets of homologous chromosomes, is found in a variety of malignant tumors and is thought to be related to disease pathogenesis. However, there have been no studies that have investigated polyploidy in diffuse large B‐cell lymphoma (DLBCL). Here we reviewed clinicopathological features of 16 cases of DLBCL with polypoidy, which was defined as DLBCL with either near‐tetraploid or greater number of chromosomes as detected by the G‐band method. The frequency of polyploid DLBCL was 2.9 % (16/544), including 15 near‐tetraploid and one near‐pentaploid case. CD5, CD30 and EBER positive cases were 13 % (2/16), 13 % (2/16) and 6 % (1/16), respectively. Bcl2 positive cases were 75 % (12/16). The numbers of huge and multinucleated cells were higher in polyploid than in non‐polyploid DLBCL (P = 0.0029 and P < 0.0001, respectively). Clinical features of polyploid DLBCL included reduced infiltration of extranodal sites (2/15, 13 %) and major lymph node infiltration. Of seven cases that received chemotherapy, six responded to treatment and survived. Our results suggest that polyploid DLBCL represents a clinicopathologically characteristic group of DLBCL. This knowledge can be useful for informing more personalized and targeted management of DLBCL patients.     

Bcl-2 and BLIMP-1 expression predict worse prognosis in gastric diffuse large B cell lymphoma (DLCBL) while other markers for nodal DLBCL are not useful

Martin‐Arruti M, Vaquero M, Díaz de Otazu R, Zabalza I, Ballesteros J, Roncador G & García‐Orad A
(2012) Histopathology  60, 785–792 Bcl‐2 and BLIMP‐1 expression predict worse prognosis in gastric diffuse large B cell lymphoma (DLCBL) while other markers for nodal DLBCL are not useful Aims: Previous studies have identified clinicopathological and immunohistochemical differences among diffuse large B cell lymphomas (DLBCL) as a function of disease location. Nevertheless, there is a continuing tendency to generalize the prognostic value of various identified markers without taking into account tumour site. Accordingly, we analysed the prognostic value of several of the immunohistochemical markers that have been proposed for nodal DLBCL in a group of patients with gastric DLBCL. Methods and results: Using histochemical methods, CD10, Bcl‐6, Gcet1, MUM‐1, Bcl‐2 and BLIMP‐1 expression was investigated in 43 cases of gastric DBLCL. As in nodal DLBCLs, expression of BLIMP‐1, and of Bcl‐2 in non‐germinal centre B cell‐like (non‐GCB) patients, was associated with a worse prognosis. However, unlike nodal DBLCL, there was no significant association of prognosis with expression of CD10, Bcl‐6, Gcet1 or MUM‐1, or with categorization according to Hans or Muris algorithms. Conclusions: Although most markers of prognosis in nodal DLBCL are not useful indicators for gastric DLBCL, Bcl‐2 or BLIMP‐1 expression does correlate with worse prognosis. These data support the notion that clinicopathological features in DLBCL vary according to the disease location.     

弥漫性大B细胞淋巴瘤的临床病理和免疫组织化学特征

目的 探讨弥漫性大B细胞淋巴瘤临床和病理组织特征以及免疫组织化学特异性抗体在其诊断和鉴别诊断中的价值。方法 收集60例弥漫性大B细胞淋巴瘤,总结其临床资料和病理学特点,用免疫组织化学EnVision^TM两步法标记白细胞共同抗原（LCA）、L26、BLA36、CD30和bcl-6抗体。结果 76．7％（46／60）弥漫性大B细胞淋巴瘤的发病年龄集中在40－70岁,淋巴结内外均可累及,90．0％（54／60）患者临床分期为Ⅱ（24／54）、Ⅲ（21／54）、Ⅳ（9／54）期。组织病理形态：中心母细胞淋巴瘤占88．3％（53／60）,免疫母细胞淋巴瘤占3．3％（2／60）,间变性大细胞淋巴瘤占3．3％（2／60）,富于T细胞的B细胞淋巴瘤占5．0％（3／60）。免疫标记LCA、L26、BLA36表达率为100．0％（60／60）,CD30表达率为3．3％（2／60）,bcl-6表达率为95．0％（57／60）。结论 弥漫性大B细胞淋巴瘤是一组异质性肿瘤,侵袭性大,必需结合其组织病理形态和特异抗体的免疫组织化学检测进行诊断和鉴别诊断。     

Anaplastic variant of diffuse large B‐cell lymphoma: Reappraisal as a nodal disease with sinusoidal involvement

Anaplastic variant (av) of diffuse large B‐cell lymphoma (DLBCL) is morphologically defined in the 2017 World Health Organization classification, but still an enigmatic disease in its clinicopathologic distinctiveness, posing the differential diagnostic problem from gray zone lymphoma (GZL) and classic Hodgkin lymphoma (cHL). Thirty‐one cases previously diagnosed as avDLBCL were reassessed. Of these, 27 (87%) and 4 (13%) were node‐based and extranodal diseases, respectively. They were further reclassified into nodal avDLBCL (n = 18), nodal CD30+ DLBCL with T‐cell/histiocyte‐rich large B‐cell lymphoma‐like features (CD30+ DLBCL‐THRLBCL) (n = 6), GZL with features intermediate between DLBCL and cHL (n = 3) and CD30+ extranodal DLBCL, NOS (n = 4). The nodal avDLBCL cases had a sheet‐like proliferation of large cells and/or Hodgkin/Reed‐Sternberg (HRS)‐like cells in 12 (67%) notably with a sinusoidal pattern in 16 (89%). They showed an expression of CD20 and/or CD79a in all and CD30 in 15 of 18. All of them were negative for PD‐L1 on tumor cells, although HRS‐like cells showed negativity or partial loss of other B‐cell markers to varying degrees. The present study highlighted the distinctiveness of the nodal avDLBCL with sinusoidal pattern, but without neoplastic PD‐L1 expression, which provide refined diagnostic criteria for a more precise pathologic and clinical characterization of this disease.     

SOX11 is useful in differentiating cyclin D1‐positive diffuse large B‐cell lymphoma from mantle cell lymphoma

Hsiao S‐C, Cortada I R, Colomo L, Ye H, Liu H, Kuo S‐Y, Lin S‐H, Chang S‐T, Kuo T U, Campo E & Chuang S‐S
(2012) Histopathology  61, 685–693 SOX11 is useful in differentiating cyclin D1‐positive diffuse large B‐cell lymphoma from mantle cell lymphoma Aims: To characterize the frequency and clinicopathological features of cyclin D1‐positive diffuse large B‐cell lymphoma (DLBCL) and the usefulness of SOX11 in the differential diagnosis from mantle cell lymphoma (MCL). Methods and results: We retrospectively stained 206 consecutive DLBCLs for cyclin D1, and identified three (1.5%) positive cases, comprising two in the elderly with necrosis, and a third with a starry‐sky pattern. All three cases shared the same non‐germinal centre B‐cell (non‐GCB) phenotype [CD5?/CD10?/bcl‐6+/MUM1+/SOX11?], Epstein–Barr virus (EBV) negativity, and absence of CCND1 aberrations by fluorescence in‐situ hybridization. The third case showed both BCL6 and MYC rearrangements: a double‐hit lymphoma. In the same period there were 22 MCLs, all expressing cyclin D1, with 89% cases expressing SOX11, a frequency that is statistically different from cyclin D1‐positive DLBCL. Notably, we identified a pleomorphic MCL initially misdiagnosed as DLBCL. A separate cohort of 98 DLBCL cases was negative for SOX11, with only one case expressing cyclin D1 with a GCB phenotype (CD10+/bcl‐6+/MUM1?). The two patients with tumour necrosis rapidly died of disease. The other two were in complete remission after immunochemotherapy. Conclusions: Cyclin D1‐positive DLBCLs are rare, and they are negative for SOX11 or CCND1 aberration. SOX11 is useful in differentiating cyclin D1‐positive DLBCL from MCL.     

A reassessment of primary thyroid lymphoma: high-grade MALT-type lymphoma as a distinct subtype of diffuse large B-cell lymphoma

AIMS: Primary lymphoma of the thyroid gland (PTL) is a relatively rare disease. During an 18-year period, 53 cases of primary non-Hodgkin's lymphoma involving this extranodal site were seen at our institutions. The aims of this study were to evaluate the spectrum of PTLs using current lymphoma classification concepts and immunocytochemical markers, determine whether features of MALT-type lymphoma were evident in PTL, and if there was any clinical significance of such a finding. METHODS AND RESULTS: The cases were retrospectively studied clinically, histologically and immunohistochemically. The tumours were classified according to the Revised European-American Lymphoma Classification of lymphoid malignancies (REAL classification). Thirty-eight patients were females, 15 were males and mean age at diagnosis was 66.3 years (range 38-90). Three cases were low-grade marginal zone lymphomas (low-grade MALT-type lymphomas). There were 45 diffuse large B-cell lymphomas (DLBCL) of which there were 27 DLBCL-NOS and 18 high-grade MALT-type lymphomas. Within the diffuse large B-cell lymphoma (DLBCL) category, cases were subdivided into those without (DLBCL-NOS) and those with features of 'high-grade' MALT-type lymphoma based on presence of a low-grade component or large cell lymphoepithelial lesions (HG MALT-type lymphoma). In addition there were three follicle centre lymphomas, one anaplastic large cell lymphoma and one peripheral T-cell lymphoma. Twenty cases were stage IE, 18 stage IIE, and four stage IV. All patients with low-grade MALT-type lymphoma are alive without disease. The 5-year survivals for DLBCL-NOS and HG MALT-type lymphoma were 75% and 25%, respectively. Univariate analysis (log rank) among the DLBCLs showed stage (P < 0.001) and subtype (P = 0.005) were associated with survival. Stage was associated with type of DLBCL, 65% of DLBCL-NOS being stage IE compared to 20% of HG MALT-type lymphomas. CONCLUSIONS: We conclude that primary thyroid lymphomas occur most commonly in elderly women and are frequently present in clinical stage IE and IIE. Low-grade MALT-type lymphomas are relatively uncommon but appear to have a favourable prognosis. DLBCL is the most common lymphoma and features of MALT can be seen in over one-third of cases. As a group, HG MALT-type lymphomas had a worse outcome than DLBCL-NOS, primarily due to higher clinical stage at diagnosis. These two subtypes of DLBCL appear to be distinct clinical and histological entities.     

Activation of the NF-kappaB signalling pathway in diffuse large B-cell lymphoma: clinical implications

Aim: To characterize the activation of the nuclear factor (NF)‐κB pathway in diffuse large B‐cell lymphoma (DLBCL) by immunohistochemistry. Methods and results: Sixty‐six DLBCLs treated with anthracycline‐containing chemotherapy were evaluated with antibodies against phosphorylated p65 (P‐p65), p65, p50, p52, IKKα, and phosphorylated IκB (P‐IκB). NF‐κB activation was based on the expression of P‐p65, P‐IκB, and nuclear expression of p65 or p52 in the tumour cells. P‐p65 and P‐IκB were expressed in 13 (20%) and 17 cases (26%), respectively. p65, p52 and IKKα were found in the cytoplasm. A correlation was found between expression of P‐p65 and P‐IκB (P < 0.0001), but not between the two subtypes of DLBCL [germinal centre B cell and non‐germinal centre (GC)]. P‐p65+ tumours showed a better response to chemotherapy (P = 0.025) and a trend to increased event‐free survival (P = 0.08). However, P‐IκB expression was not associated with either clinical response or survival. Bcl‐2 was not preferentially expressed on DLBCL tumours with NF‐κB activation, as determined by expression of P‐p65 and P‐IκB proteins. Conclusions: NF‐κB activation in DLBCL is preferentially mediated through the classical pathway and a novel mechanism involving phosphorylation of p65. Activation of NF‐κB by P‐p65 is associated with good prognosis. NF‐κB activation is not confined to non‐GC DLBCL exclusively.     

Nodular lymphocyte predominant Hodgkin lymphoma and diffuse large B-cell lymphoma: a study of six cases concurrently involving the same site

Cotta C V, Coleman J F, Li S & Hsi E D
(2011) Histopathology  59 , 1194–1203
Nodular lymphocyte predominant Hodgkin lymphoma and diffuse large B‐cell lymphoma: a study of six cases concurrently involving the same site Aims: Nodular lymphocyte‐predominant Hodgkin lymphoma (NLPHL) is a slowly progressing neoplasm with a favourable prognosis. However, in a minority of cases (3–12%) it progresses to a clonally related diffuse large B‐cell lymphoma (DLBCL), diagnosed between 6 months and 24 years after NLPHL. This study investigated six cases of NLPHL and DLBCL at the same location. Methods and results: The patients were five men and one woman. In four cases, the site was an axillary lymph node, and in two it was inguinal. In all cases, NLPHL areas had typical morphological and immunophenotypic features. DLBCL involvement was multifocal, diffuse, and characterized by large centroblastic and anaplastic cells. Immunohistochemical studies showed DLBCL cells to be positive for CD20, CD45, and BCL6. In one case, DLBCL cells were positive for BCL2, and in two cases they were positive for MUM‐1. There were no networks of follicular dendritic cells (FDC) associated with DLBCL. Rosettes of PD‐1‐positive and CD57‐positive cells surrounding malignant cells in NLPHL were absent in DLBCL. All the cases were negative for Epstein–Barr virus. No translocations involving MYC were identified in DLBCL. Treatment and outcome were known in four cases. All of these patients were treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R‐CHOP), and this was followed by clinical remission (CR). Conclusions: In adequately sampled tumors, DLBCL can be associated with NLPHL at diagnosis. Diffuse architecture, loss of FDC networks, sometimes immunophenotype shift are characteristics of DLBCL associated with NLPHL. Treatment with R‐CHOP usually leads to CR.     

Clear cell variant of diffuse large B-cell lymphoma: a case report and review of the literature

Diffuse large B cell lymphoma (DLBCL) is a diffuse proliferation of large neoplastic B lymphoid cells with nuclear size equal to or exceeding that of normal macrophage nuclei. The DLBCL morphological variants are centroblastic, immunoblastic, T-cell- and histiocyte-rich, anaplastic, plasmablastic, anaplastic lymphoma kinase-positive, and primary mediastinal large B-cell lymphoma (PMBCL). These histopathologically-recognized morphological variants respond differently to treatment and have distinct prognoses. We report a case of a 43-year-old patient who presented pain in the lower abdomen that had begun four months prior. Ultrasound-guided biopsy revealed epithelial cell features and a partial alveolar growth pattern. We discovered large diffuse areas comprising large cells with slightly irregular nuclei and very clear cytoplasm. These features were similar to those of clear cell carcinoma in renal tissue, suggesting the possibility of an epithelial neoplasm. To test this possibility, immunohistochemistry for cluster designation markers was performed, but the diffuse areas were found to be positive only for CD45. Additional immunohistochemistry was performed, and the diffuse areas were found to be positive for CD20, CD79a, P53, and Mum-1. Based on these characteristics, a diagnosis of a clear cell variant of DLBCL was made, and the patient was treated with chemotherapy. Precise histological diagnosis is crucial for clinical management and ultimately for patient survival. There has been one additional report of a case of clear cell DLBCL, in outside the mediastinum. The features we identified can be used to define a new subtype of DLBCL. The expression of P53 and Mum-1 suggest a poor prognosis.     

Comparative clinicopathological study of primary CNS diffuse large B-cell lymphoma and intravascular large B-cell lymphoma

Primary CNS diffuse large B-cell lymphoma (CNS DLBCL) is confined to the CNS, and constitutes a distinct entity. In the present study a series of 40 Japanese patients with CNS DLBCL who presented with neurological, but not systemic symptoms, was reviewed. Median survival was 18.7 months. CD5, CD10, Bcl-6, MUM-1, and Bcl-2 were positive in 30%, 10%, 84%, 100%, and 93% of patients, respectively. All CD10-negative patients had non-germinal center B-cell type. There was no significant difference in survival among the immunophenotypic subgroups. CNS DLBCL appeared to be homogenous as a group, which prompted the comparison with another distinct extranodal entity, intravascular large B-cell lymphoma (IVLBCL) in Japanese patients. CNS DLBCL patients did not differ in age, sex, or immunophenotype, including CD5 positivity, from IVLBCL patients, but were significantly less likely to have poor prognostic parameters than IVLBCL patients: the international prognostic index score was low or low–intermediate in 86% of CNS DLBCL patients and high or high–intermediate in 98% of IVLBCL patients. Notably, despite this difference, their survival curves almost overlapped. The present study highlights the issue of clinical distinctiveness of aggressive extranodal lymphomas, the peculiar migration and localization of which should be further clarified.     

B cell lymphoma,unclassifiable, with features intermediate between diffuse large B cell lymphoma and classical hodgkin lymphoma: Diagnosis by fine‐needle aspiration cytology

A 58‐year‐old lady presented with mediastinal lymphadenopathy. A thoracoscopic ultrasound‐guided fine‐needle aspiration showed large atypical epithelioid cells arranged in cohesive sheets and dispersed as single cells with intact cytoplasm amid a background of lymphocytes and histiocytes. A cytological diagnosis of “a malignant neoplasm” was made, raising a broad list of differential diagnoses. A broad panel of immunocytochemical stains performed on the cell block was indicative of a lymphoproliferative disorder, but the immunophenotype was intermediate between diffuse large B cell lymphoma (DLBCL) and classical Hodgkin lymphoma (cHL). Diffuse and strong reactivity to CD20, CD79a, and PAX‐5, and weak reactivity to CD30, was in favor of a DLBCL, or more precisely mediastinal (thymic) large B cell lymphoma (MLBL). However, there were negative staining for LCA, OCT‐2, and BOB‐1 as well as positive staining for EBV‐encoded RNA, which were against a diagnosis of MLBL and raised the possibility of cHL. The absence of RS cells and the typical mileu, the negativity for CD15 and the strong positivity of CD20 and PAX‐5 were against a diagnosis of cHL. On this basis, the diagnosis of “B‐cell lymphoproliferative disorder with features intermediate between DLBCL and cHL” was rendered. The diagnosis was subsequently confirmed on excisional biopsy. This case report demonstrates broad differential diagnoses raised by this diagnostic entity and the importance of an adequate cell block for accurate designation. Diagn. Cytopathol. 2014;42:690–693. © 2013 Wiley Periodicals, Inc.     

CD10 and Bcl10 expression in diffuse large B-cell lymphoma: CD10 is a marker of improved prognosis

AIMS: Diffuse large B-cell lymphoma (DLBCL), the most common subtype of non-Hodgkin's lymphoma, is clinically and pathologically heterogeneous. The Bcl10 gene was recently isolated from the breakpoint region of t(1;14)(p22;q32) in mucosa-associated lymphoid tissue (MALT) lymphomas, and is considered to be an apoptosis-associated gene. CD10 is considered to be a marker of follicular centre B-cell differentiation. To assess the clinical significance and roles of CD10 and Bcl10 in DLBCL, we analysed 138 cases, using immunohistochemical methods. METHODS AND RESULTS: CD10 expression was limited to the cytoplasm, whereas Bcl10 expression was detected in the cytoplasm and/or nuclei. CD10 expression was detected in 39 of 138 cases (28.2%), cytoplasmic Bcl10 in 68 cases (49.2%), and nuclear Bcl10 in 34 cases (24.6%). Nuclear Bcl10 was detected in 14 of 28 cases (50%) of extranodal DLBCL, but only 20 of 110 cases (18.2%) of nodal DLBCL. Cytoplasmic Bcl10 was detected in 19 of 28 cases (67.8%) of extranodal DLBCL and 49 of 110 cases (44.5%) of nodal DLBCL. CD10 expression closely correlated with improved survival (68% overall survival (OS) vs. 48% OS), but not with site of disease. A high International Prognostic Index (IPI) was considered to be a poor prognostic factor associated with a shorter OS. CD10 expression was detected in 27 of 84 cases (32.1%) with low-risk IPIs, and in 12 of 54 cases (22.2%) with high-risk IPIs. In the low-risk group, cases expressing CD10 carried a better prognosis than CD10- cases (93% OS vs. 71% OS), whereas this was not the case in the high-risk group (25% vs. 20%). CONCLUSIONS: Bcl10 expression was associated with extranodal DLBCL, but not with prognosis. CD10 expression was closely associated with improved survival, but not with risk as predicted by IPI. Overall, our results suggest that CD10 expression may be useful, in combination with clinical parameters, for determining the prognosis of DLBCL.     

CD43 expression in B cell lymphoma.

AIMS: To determine the expression of CD43 in frozen sections in a range of B cell lymphomas. METHODS: The monoclonal antibody WR14, clustered provisionally in the Fourth Leucocyte Typing Workshop as a CD43 reagent, was investigated by epitope blocking studies on formalin fixed reactive lymph node tissue, using the established CD43 antibody MT1, to validate its use as a CD43 reagent. CD43 expression was studied in 131 immunophenotypically defined B cell lymphomas, including lymphocytic lymphoma (Lc, n = 13), centrocytic lymphoma (Cc, n = 14), and a range of follicle centre cell lymphomas (FCC) including centroblastic/centrocytic follicular (CbCcF, n = 48), centroblastic diffuse (CbD, n = 39), centroblastic/centrocytic diffuse (CbCcD, n = 4), centroblastic follicular and diffuse (Cb FD, n = 3) and centroblastic/centrocytic follicular and diffuse (CbCc FD, n = 1). Nine lymphomas of mucosa associated lymphoid tissue (MALT) were also examined. RESULTS: Epitope blocking studies showed that WR14 is a CD43 reagent that binds to an epitope identical with or close to that recognised by MT1. Eleven of 13 (84%) cases of Lc and 11 of 14 (78%) cases of Cc expressed CD43; 87 of 95 (91%) cases of FCC did not. All eight low grade lymphomas of MALT were negative. One high grade lymphoma, transformed from a low grade MALT lymphoma, was positive for CD43. The expression of CD43 by tumours of B cell lineage was associated with the expression of CD5 (p < 0.001) although either antigen could occasionally be found in the absence of the other. CONCLUSION: CD43 reagents can be used in conjunction with CD5 antibodies for the immunophenotypic discrimination of follicle centre cell lymphomas from non-follicle centre cell lymphomas.     

Epstein–Barr virus‐positive diffuse large B cell lymphoma arising from a chronic lymphocytic leukemia: Overlapping features with classical Hodgkin lymphoma

A small proportion of patients with chronic lymphocytic leukemia (CLL) may progress to large cell lymphoma, or Richter syndrome (RS). The large cells of RS may arise through transformation of the original CLL clone (clonally related) or represent a new neoplasm (clonally unrelated), which might be Epstein–Barr virus (EBV)‐associated. We present a 61‐year‐old male with 5‐year history of CLL who developed RS on bilateral adrenal glands. The tumor showed a vague nodular growth pattern separated by thick fibrous bands and the tumor cells were large and pleomorphic, with focal sheet‐like growth pattern, in a background of small B and T‐lymphocytes. The large tumor cells were positive for CD15, CD19, CD20 (intensely and diffusely), CD30, fascin, PAX5, MUM1, OCT2, and LMP‐1 by immunohistochemical stains, and EBV by in situ hybridization. The tumor was diagnosed as EBV‐positive diffuse large B cell lymphoma (DLBCL), with overlapping features of classic Hodgkin lymphoma (CHL). The patient received salvage chemotherapy and was free of disease 2 years after adrenalectomy. We speculated that our case was a clonally unrelated tumor with his underlying CLL and discussed the differential diagnoses between EBV‐positive DLBCL and CHL in the setting of RS.     

Primary central nervous system B cell lymphoma with features intermediate between diffuse large B cell lymphoma and Burkitt lymphoma

B cell lymphoma with features intermediate between diffuse large B cell lymphoma and Burkitt lymphoma (DLBCL/BL) is a new lymphoma entity which is recognized in the current World Health Organization (WHO) classification (2008). We report a case of a primary central nervous system lymphoma (PCNSL) with findings consistent with DLBCL/BL. It is characterized by a very aggressive clinical course, and a widespread multifocal involvement of the CNS. Our case shows that a DLBCL/BL can manifest in the CNS alone without any systemic involvement.     

Primary pancreatic diffuse large B‐cell lymphoma diagnosed by endoscopic ultrasound guided FNAC: A rare entity

Primary pancreatic lymphoma (PPL) is an uncommon neoplasm which can clinico‐radiologically mimic carcinoma. But the management of these patients differs from that of a carcinoma. Endoscopic ultrasound (EUS) guided fine‐needle aspiration (FNA) serves as a potential tool to identify pancreatic lymphomas and thus prevent an invasive diagnostic test. This case report describes the presentation and diagnosis of primary pancreatic lymphoma. A 37‐year‐old female presented with nausea, vomiting with signs of icterus and elevated liver function test and Bilirubin. Abdominal computed tomography (CT) revealed a hypodense lesion in the head of the pancreas. EUS guided FNA was performed and cytological material was collected. The lesion was diagnosed as Non‐Hodgkin Lymphoma (NHL) and subtyped as diffuse large B‐cell lymphoma‐germinal centre (DLBCL‐GCB) base on immunohistochemistry on cell block. The patient was started on rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (RCHOP) regimen. EUS guided FNA along with ROSE, cell bock, and immunocytochemistry helps in the diagnosis of primary pancreatic lymphoma.     

Clinicopathological analysis of a composite lymphoma containing both T‐ and B‐cell lymphomas

Composite lymphomas (CLs) have been reported in 1–4.7% of all lymphomas, however, CLs containing both T‐ and B‐cell lymphomas (CTBLs) are very rare. Here, we examined the clinical and pathological features of 29 CTBLs. These CTBLs included 21 patients with angioimmunoblastic T‐cell lymphoma (AITL) and diffuse large B‐cell lymphoma (DLBCL), two with adult T‐cell leukemia/lymphoma and DLBCL, one with AITL and Follicular lymphoma, one with Lennert lymphoma and DLBCL, one with subcutaneous panniculitis‐like T‐cell lymphoma and DLBCL, one with peripheral T‐cell lymphoma (PTCL) and DLBCL, one with cutaneous T‐cell lymphoma and DLBCL, and one with PTCL and chronic lymphocytic leukemia. Eighteen of 27 patients (67%) were shown to be Epstein‐Barr virus (EBV)‐encoded RNA‐positive in their B‐cell lymphoma component. T‐cell and B‐cell clonality were confirmed by flow cytometry, Southern blot analysis, and/or polymerase chain reaction (PCR). Using Southern blot analysis, clonal immunoglobulin heavy chain (IgH) and T‐cell receptor (TCR) rearrangements were detected in 11 of 21 and 15 of 24 cases, respectively. Using PCR analysis, clonal IgH and TCR rearrangements were detected in 7 of 8 and 7 of 7 Southern blot‐negative cases, respectively. Our results suggested that PCR analysis was useful in diagnosing CTBL.     

CD5-positive diffuse large B cell lymphoma arising from a CD5-positive follicular lymphoma

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-J(H) break point.     

Clinicopathological features of 49 primary gastrointestinal diffuse large B‐cell lymphoma cases; comparison with location,cell‐of‐origin,and frequency of MYD88 L265P

The gastrointestinal (GI) tract is the most common primary site of extranodal diffuse large B‐cell lymphoma (DLBCL), with approximately one‐third of extranodal DLBCL occurring in the GI tract. We investigated the clinicopathological features and immunohistochemically‐assessed cell‐of‐origin of 49 GI DLBCL cases (stomach, 24; small intestine, 10; colon, 15) and also examined the presence of MYD88 L265P as recently this mutation has been frequently identified in ABC‐like DLBCL, particularly in extranodal sites. Small intestinal DLBCL was characterized by the preponderance of women (P = 0.041) and elevated LDH (P = 0.002) and soluble interleukin‐2 receptor (P = 0.033). Small intestinal DLBCL more frequently showed anemia (P = 0.031) and elevated CRP (P = 0.029) than gastric DLBCL. ABC‐like phenotype was seen in 71.4 % cases (stomach, 79 %; small intestine, 70 %; colon, 60 %). MYD88 L265P was detected in 6.1 % cases; all were primary gastric DLBCL with ABC‐like phenotype but had no distinct clinicopathological features. In conclusion, GI DLBCL had different clinicopathological features according to the primary site especially in the small intestine. Also, MYD88 L265P had little involvement in GI DLBCL compared with other extranodal DLBCLs, suggesting that its pathogenesis might be different from that of organs with a high frequency of MYD88 L265P.