Diffuse large B-cell lymphomas with plasmablastic differentiation represent a heterogeneous group of disease entities

Plasmablastic lymphoma was initially described as a variant of diffuse large B-cell lymphoma (DLBCL) involving the oral cavity of HIV+ patients and characterized by immunoblastic morphology and a plasma cell phenotype. However, other lymphomas may exhibit similar morphologic and immunophenotypic features. To determine the significance of plasmablastic differentiation in DLBCL and examine the heterogeneity of lymphomas with these characteristics, we examined 50 DLBCLs with low/absent CD20/CD79a and an immunophenotype indicative of terminal B-cell differentiation (MUM1/CD38/CD138/EMA-positive). We were able to define several distinct subgroups. Twenty-three tumors were classified as plasmablastic lymphoma of the oral mucosa type and showed a monomorphic population of immunoblasts with no or minimal plasmacytic differentiation. Most patients were HIV+ and EBV was positive in 74%. Eleven (48%) cases presented in the oral mucosa, but the remaining presented in other extranodal (39%) or nodal (13%) sites. Sixteen cases were classified as plasmablastic lymphoma with plasmacytic differentiation. These were composed predominantly of immunoblasts and plasmablasts, but in addition exhibited more differentiation to mature plasma cells. Only 33% were HIV+, EBV was detected in 62%, and 44% had nodal presentation. Nine cases, morphologically indistinguishable from the previous group, were secondary extramedullary plasmablastic tumors occurring in patients with prior or synchronous plasma cell neoplasms, classified as multiple myeloma in 7 of the 9. Two additional neoplasms were an HHV-8+ extracavitary variant of primary effusion lymphoma and an ALK+ DLBCL. HHV-8 was examined in 39 additional cases, and was negative in all. In conclusion, DLBCLs with plasmablastic differentiation are a heterogeneous group of neoplasms with different clinicopathological characteristics that may correspond to different entities.     

Epstein-Barr virus negative clonal plasma cell proliferations and lymphomas in peripheral T-cell lymphomas: a phenomenon with distinctive clinicopathologic features

Clonal B-cell populations have been described in peripheral T-cell lymphomas (PTCL) as secondary Epstein-Barr virus (EBV) driven B-cell expansions that may evolve to an overt B-cell lymphoma. EBV-negative B-cell proliferations associated with T-cell lymphomas are uncommon and not well characterized. We studied 15 patients who developed an EBV-negative B-cell proliferation or malignant lymphoma associated with PTCL. The T-cell tumors were 8 PTCL, not otherwise specified, 4 angioimmunoblastic T-cell lymphomas, and 3 cutaneous PTCL. The B-cell component was intermingled with the PTCL in all patients and it was classified as clonal/monotypic plasma cell proliferation in 8 lesions, clonal/monotypic large B-cell proliferation in 4 patients, and B-cell lymphoma with plasmacytic/plasmablastic differentiation in 3 patients. Two patients had 2 clonally unrelated plasma cell proliferations associated with the same PTCL. All cases showed cytoplasmic Ig light chain restriction. Clonal IgH and T-cell receptor rearrangements were detected in 11/12 and 11/13 cases examined, respectively. EBV, cytomegalovirus, and HHV-8 were not observed in any of the examined cases. Sequential samples in 7 patients showed persistence of the PTCL and the B-cell component in 4, the PTCL without the B-cell lymphoma in 2, and progression of the B-cell neoplasm in 1. Patients followed an aggressive clinical course similar to conventional PTCL. In conclusion, EBV-negative clonal or mononotypic B-cell proliferations in patients with PTCL present with a spectrum of lesions ranging from plasma cell proliferations to overt lymphomas with plasmacytic/plasmablastic features. The distinctive features of these patients suggest that these lesions represent a specific phenomenon in PTCL.     

Clinicopathologic Features of B-Cell Lineage Neoplasms With Aberrant Expression of CD3: A Study of 21 Cases

CD3 expression by immunohistochemistry was historically considered restricted to T-lineage or NK-lineage neoplasms but recently has been reported in rare cases of mature B-cell neoplasms, frequently in association with Epstein-Barr virus. Here, we describe the pathologic features of 21 B-cell lineage neoplasms that express CD3 protein by immunohistochemistry: 12 diffuse large B-cell lymphomas (DLBCLs); 2 plasmablastic lymphomas (PBLs); 4 plasma cell neoplasms; 2 Burkitt lymphomas; and 1 nodal follicular lymphoma, grade 3A. CD20 expression was negative or only partially positive in 13/21 cases. Epstein-Barr virus was positive in 3/20 tested cases (2 PBLs and 1 DLBCL). All tested neoplasms (14/14) had clonal immunoglobulin gene rearrangements, and no clonal T-cell gene rearrangements were detected (0/14). The 12 DLBCLs segregated into 2 main groups: 7 demonstrated features of plasmacytic differentiation but did not meet criteria for PBL, and 5 had anaplastic features. In addition to morphology, other features shared among the DLBCLs with plasmacytic differentiation, the plasma cell neoplasms, and the PBLs included extranodal presentation, cytoplasmic localization of CD3, and lack of expression of other T-cell antigens in most cases. In contrast, DLBCLs with anaplastic features and the single follicular lymphoma coexpressed multiple T-cell antigens in a predominantly membranous pattern and presented with nodal disease in a relatively younger patient population. Our data expand the spectrum of morphologic, phenotypic, and clinical features of B-cell neoplasms aberrantly expressing CD3. As these neoplasms often lack typical expression of B-cell antigens, knowledge of these features will help avoid misclassification.     

Is lymphoplasmacytic lymphoma/immunocytoma a distinct entity? A clinicopathologic study of 20 cases

Lymphoplasmacytic lymphoma/immunocytoma (LLI) was defined initially as a small B-cell lymphoma with plasmacytoid or plasmacytic features. Because other types of small B-cell lymphoma, particularly marginal zone B-cell lymphoma may exhibit plasmacytic differentiation, the revised European-American lymphoma classification and World Health Organization has defined LLI more narrowly to exclude other small B-cell lymphomas. The goal of this study was to reevaluate LLI as a clinicopathologic entity. Twenty cases were selected from 43 previously diagnosed as "small lymphocytic lymphoma, plasmacytoid" or "immunocytoma" from 1985 to 1998. Cases fulfilling the criteria for B-cell small lymphocytic lymphoma, follicular lymphoma, marginal zone B-cell lymphoma, or other types of B-cell lymphoma were excluded. The histopathology and immunoreactivity for CD20, CD79a, CD3, CD43, CD23, CD5, kappa, lambda, and immunoglobulins (Ig's) M, G, and A were reviewed, in addition to available clinical findings. There were 13 men and seven women, with a mean age of 69 years. Five patients had documented Waldenstr?m's macroglobulinemia (WM). Three architectural patterns were observed. Pattern A (seven of 20) showed open sinuses, small follicles, and hemosiderosis; pattern B (four of 20) showed hyperplastic follicles; and pattern C (nine of 20) showed diffuse effacement. Epithelioid histiocytes were prominent in patterns B and C but absent in A. Cytologically, six of 20 were polymorphous with 10% to 40% transformed cells; 14 of 20 were lymphoplasmacytic. Five cases showed minor foci of monocytoid B cells. One case showed a composite histology of LLI and small lymphocytic lymphoma. Amyloid was present in two cases. All cases were CD20 and/or CD79a immunoreactive, with two of 20 positive for CD43. Twelve cases were kappa monoclonal and eight cases were lambda monoclonal. Twelve of 17 cases that could be evaluated were positive for IgM and five were positive for IgG. All cases were negative for CD5 and CD23 with the exception of the one case with a composite histology. Eleven of 20 patients with available follow-up died of disease (median, 48 months), and eight of 20 are alive with disease at a follow-up of 6 months to 2 years. LLI does appear to represent a distinct clinicopathologic entity even though it shows morphologic heterogeneity and overlapping features with marginal zone B-cell lymphoma and small lymphocytic lymphoma. Recognition of LLI is important because the overall prognosis may be worse than for other types of small B-cell lymphomas.     

Post-transplant lymphoproliferative diseases in Asian solid organ transplant recipients: late onset and favorable response to treatment

Chan TSY, Hwang Y‐Y, Gill H, Au W‐Y, Leung AYH, Tse E, Chim C‐S, Loong F, Kwong Y‐L. Post‐transplant lymphoproliferative diseases in Asian solid organ transplant recipients: late onset and favorable response to treatment. Abstract: Nineteen consecutive patients with post‐transplant lymphoproliferative disorders (PTLD) in an Asian population were reviewed. The histopathologic diagnoses were monomorphic (CD20‐positive diffuse large B‐cell lymphoma, n = 14); plasmacytic (n = 1); Burkitt‐like (n = 1); natural killer cell lymphoma (n = 1); lymphomatoid papulosis (n = 1); and classical Hodgkin lymphoma (n = 1). Early‐onset (相似文献   

EBV-positive extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue in the posttransplant setting: a distinct type of posttransplant lymphoproliferative disorder?

The 2008 World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues defines monomorphic posttransplant lymphoproliferative disorders (M-PTLDs) as lymphoid or plasmacytic proliferations that fulfill the criteria for one of the B-cell or T/NK-cell neoplasms recognized in immunocompetent patients. However, indolent B-cell lymphomas, such as extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), are specifically excluded from this category. In this study, we describe the clinicopathologic features of 4 posttransplant lymphoma-like proliferations that were Epstein-Barr virus (EBV) positive, but were otherwise completely typical for a MALT lymphoma. The 4 patients (age, 12 to 71 y) had received solid organ transplants (2 hearts, 1 kidney, 1 kidney/pancreas) at a median of 116 months before presentation, and had been maintained on varying immunosuppressive regimens that included cyclosporine, azathioprine, tacrolimus, and sirolimus. Three of the 4 patients presented with solitary subcutaneous masses, whereas the fourth patient presented with a solitary orbital soft tissue mass. All the 4 cases were morphologically typical for MALT lymphoma, demonstrated plasmacytic differentiation with IgA heavy chain restriction (3 cases κ positive, 1 case λ positive), and were diffusely EBV-encoded small RNA positive. Patients were followed for a median of 44.9 months, and all achieved a complete response following various regimens that included reduced immunosuppression with or without antiviral therapy, local surgical excision, rituximab, or local radiation therapy. The uniform EBV positivity and response to immune reconstitution in some cases suggest that EBV-positive MALT lymphomas arising in the posttransplant setting should be included among PTLDs. Whether their distinctive subcutaneous/soft tissue localization and IgA positivity are uniform features will require identification of additional cases.     

Sinonasal lymphoma: a clinicopathologic analysis of 58 cases from the Massachusetts General Hospital.

Few large series compare lymphomas of the nasal cavity with those of the paranasal sinuses. We studied the cases of 58 patients, 34 males and 24 females, aged 7 to 92 years (mean, 57 years), who had lymphoma involving the nasal cavity or paranasal sinuses. Thirty-three patients had diffuse large B-cell lymphoma (DLBCL). Twenty-three were male and 10 were female, with an age range of 7 to 91 years (mean, 63 years); two were HIV-positive. Only 2 of 11 cases tested (one in an HIV-positive patient and one of lymphomatoid granulomatosis type) were Epstein-Barr virus (EBV)-positive. Thirty (91%) involved paranasal sinuses, 10 with nasal involvement, whereas three cases had nasal, but not sinus, involvement. At last follow-up, 16 (67%) were free of disease 7 to 169 months later (mean, 65 months), and 8 (33%) had died of disease 2 to 166 months later (mean, 45 months). Seventeen patients had nasal-type natural killer (NK)/T-cell lymphoma. There were 10 women and 7 men, aged 27 to 78 years (mean, 48 years). Thirteen of 14 were EBV-positive. Sixteen patients had nasal involvement, eight with sinus involvement. Eleven (73%) of 15 were alive and well 6 to 321 months later (mean, 139 months), three (20%) died of lymphoma 1, 11, and 12 months later, and one (7%) is alive with disease. There was one case each of marginal zone B-cell lymphoma, Burkitt's lymphoma, Burkitt-like lymphoma, peripheral T-cell lymphoma of unspecified type, and adult T-cell lymphoma/leukemia. In an additional three cases, the lymphomas were composed predominantly of large cells, but no immunophenotyping could be performed for subclassification. In 19 cases (17 DLBCLs, 1 Burkitt-like lymphoma, and 1 lymphoma of uncertain lineage), presenting symptoms included complaints related to the eyes. In 16 cases (13 DLBCLs, 1 Burkitt-like lymphoma, 1 nasal NK/T-cell lymphoma, and 1 lymphoma of uncertain lineage), the orbit was invaded by lymphoma. In our series, the most common lymphoma to arise in the sinonasal area is DLBCL, followed by nasal NK/T-cell lymphoma. Comparison of these two types of lymphoma showed that lymphomas involving sinuses without nasal involvement were predominantly DLBCLs (20 of 21), whereas nasal cavity lymphomas without sinus involvement were usually NK/T-cell type (8 of 11) (p = 0.000125). Compared with patients with DLBCL, patients with nasal NK/T-cell lymphoma were overall younger, with a lower male-to-female ratio. Lymphomas of B-cell lineage were more likely to be associated with symptoms related to the eyes (p < 0.0005) and to have extension to the orbit (p < 0.01) than were lymphomas of T- or NK-cell lineage. In contrast to results of Asian studies in which nasal NK/T-cell lymphoma has a very poor prognosis, our nasal NK/T-cell lymphomas had an outcome similar to that of DLBCL.     

t(8;13)-positive bilineal lymphomas: report of 6 cases

The 8p11 myeloproliferative syndrome (EMS) is a rare hematologic malignancy characterized by myeloid hyperplasia, eosinophilia, and precursor lymphoblastic lymphoma, associated with balanced translocations involving chromosome 8p11, most commonly t(8;13)(p11;q12). Approximately 75% of EMS patients present with or develop precursor T-cell lymphoblastic lymphoma, and most subsequently develop acute myeloid leukemia. Here we describe the morphologic and immunophenotypic features of 6 cases of t(8;13)-positive bilineal lymphoma of mixed T-cell and myeloid lineage, 5 in lymph nodes and 1 in breast. The patients, 3 males and 3 females, ranged in age from 6 to 19 years. Histologically, each tumor was composed of 2 distinct cellular components: small to medium-sized T cells with scant cytoplasm that resembled lymphoblasts, and larger immature-appearing cells with more abundant eosinophilic cytoplasm that resembled myeloblasts, a subset of which expressed myeloid antigens. In all cases, the latter component tended to surround residual lymphoid follicles and/or blood vessels. Numerous eosinophils and prominent high endothelial venules were present in all of the lymph node specimens. Interestingly, cells of both components expressed CD3 on immunohistochemical stains. In conclusion, EMS associated with t(8;13) should be suspected in patients with a bilineal tumor that involves lymph nodes or other extramedullary sites. We believe that these bilineal neoplasms of mixed T-cell and myeloid lineages, which present as lymphoma, are analogous to bilineal leukemias. They likely arise from an early hematopoietic cell with potential to differentiate along T-cell and myeloid pathways.     

Sinonasal NK/T-cell lymphomas in the United States

Sinonasal natural killer (NK)/T-cell lymphomas are common in Asia and areas of South and Central America but are rarely seen in the United States, where they have not been as well characterized. Fifteen cases diagnosed in Southern California were studied with respect to histologic features, immunophenotype, Epstein-Barr virus EBER in-situ hybridization (EBV EBER-ISH), and T-cell receptor gamma chain (TCR-gamma) gene rearrangement. Although ethnic background was available for only seven patients, six were of Asian or Hispanic descent with only one non-Hispanic white known. Twelve presented as sinonasal lesions, but three were limited to the oropharynx. Most cases (11 of 15) demonstrated both necrosis and an angiodestructive pattern. All cases demonstrated cytoplasmic CD3 positivity (15 of 15), and were positive for both TIA-1 and granzyme B (14 of 14). Perforin was positive in 5 of 14. CD56 was expressed in 10 of 15 and CD8 in 3 of 15. EBV EBER-ISH was positive in 14 of 14 and TCR-gamma gene rearrangement was detected in 1 of 14 cases. None (0 of 14) were positive for CD16 or CD57. Although CD16-positive histiocytes were abundant, double-label EBER-ISH/IHC failed to identify CD16 expression on EBV-positive tumor cells. Three cases with pleomorphic large cell morphology showed focal CD30 positivity, raising the differential diagnosis of anaplastic large cell lymphoma, but all were ALK-1-negative and otherwise similar to the other cases of NK/T-cell lymphoma. Sinonasal NK/T-cell lymphomas in the United States most often occur in ethnic groups from areas of reported high frequency (Asia, Central and South America), although less commonly than in endemic populations, and are otherwise similar phenotypically. A combined approach, including immunohistochemistry, EBV EBER-ISH, and TCR gene rearrangement studies, is most helpful to arrive at the correct diagnosis.     

Bone marrow involvement in lymphomas with hemophagocytic syndrome at presentation: a clinicopathologic study of 11 patients in a Western institution.

Hemophagocytic syndrome (HPS) is a clinicopathologic syndrome that can reveal a non-Hodgkin's lymphoma. The pathologic features of lymphoma associated with HPS remain ill defined. We studied 11 lymphomas associated with HPS on initial bone marrow biopsies, consecutively diagnosed during a 6-year period in a Western institution. There were seven diffuse large B-cell lymphomas (DLBCLs), three T-cell lymphomas (one peripheral T-cell lymphoma unspecified, two hepatosplenic gammadelta T-cell lymphomas [HS gammadeltaTLs]), and one aggressive NK-cell lymphoma/leukemia (NKL). These lymphomas shared common clinicopathologic features with a systemic presentation, a poor outcome (nine patients died within 2 years), and a mild interstitial lymphoid infiltrate of the bone marrow at presentation in nine patients. This equivocal lymphoma infiltrate was blending with normal hematopoietic cells, and CD20 and CD3 immunolabelings were essential for its detection. A high number of reactive T (CD3+) cells, most often with a predominant cytotoxic (CD8+ TiA1+) phenotype, was present in all DLBCLs. By in situ hybridization, Epstein-Barr virus was detected in neoplastic cells of three cases (one DLBCL, one HS gammadeltaTL, and one NKL), which also showed serum viral DNA. Polymerase chain reaction studies disclosed HHV6 DNA sequences in tumor tissues of two DLBCLs, whereas HHV8 DNA was not detected. Because tumor mass indicative of lymphoma was not striking in most patients, bone marrow biopsy appears to be of great value for the diagnosis of an HPS-associated lymphoma, which may be, in Western patients, of B- as well as T- or NK-cell type. Immunostaining for CD3 and CD20 is essential to identify the common subtle lymphoma involvement. Together with a better understanding of the pathogenic processes, an early diagnosis may improve the prognosis of HPS-associated lymphoma.     

Cutaneous marginal zone lymphomas have distinctive features and include 2 subsets

Cutaneous marginal zone lymphomas (CMZL) were segregated in the WHO/EORTC consensus classification but grouped with other MALT lymphomas in the subsequent WHO classification. It has been suggested, however, that CMZL have distinctive features and might include 2 subsets. To address these issues, the clinicopathologic, phenotypic and, when possible, genotypic features of 29 CMZL with plasmacytic differentiation were assessed. The monotypic plasma cells had class-switched heavy chain expression in 22 cases, technically inadequate staining in 1 case (included with class-switched cases for analysis) and 6 were IgM. The class-switched cases had a predominance of T cells in 22 out of 23 cases with a CD4:CD8>1 in 15 out of 16 cases, usually showed nodules and scattered small B cells often with IgD apparently nonneoplastic follicles, lacked CXCR3 B-cell expression, never showed a totally diffuse growth pattern, often had prominent mast cells, and lacked known extracutaneous involvement. The IgM cases showed a predominance of B cells in 5 out of 6 (P=0.0003), a diffuse proliferation of CD20 B cells in all (P<0.0001), CXCR3+ B cells in 2 out of 5 (P<0.04), and extracutaneous disease in 3 out of 6 (P<0.008). CD21 usually disrupted follicular dendritic meshworks were seen in 9 out of 12 class-switched and 5 out of 5 IgM cases. CD123 plasmacytoid dendritic cells, PD1+ T follicular helper cells, CD25 or FOXP3+ regulatory T cells, and TIA1/granzyme B cytotoxic cells were never numerous. Only 1 out of 14 tested cases showed a low-level clonal/oligoclonal T cell receptor γ gene rearrangement. These findings support the presence of 2 types of cutaneous MALT lymphomas with the class-switched cases being the most distinctive but still sharing significant features with MALT lymphomas from other sites, specifically an extranodal extramedullary CD5-, CD10- indolent small B cell lymphoma with plasmacytic differentiation, frequent benign follicular structures, and not fulfilling the criteria for any other well-defined lymphoma.     

Plasmacytic post‐transplant lymphoproliferative disorder: a case series of nine patients

Post‐transplant lymphoproliferative disorder (PTLD) is a serious complication of organ transplantation. Although PTLD typically has a B‐cell histology, an uncommon variant, plasmacytic PTLD can present as a monoclonal plasma cell proliferation similar to plasmacytomas seen in multiple myeloma. A retrospective analysis was performed on nine patients at our center with plasmacytic PTLD as characterized by plasmacytic histology with the presence of CD138 and lack of CD20. Of the 210 adult solid organ transplant PTLD patients diagnosed between 1988 and 2012, 9 (4%) had a histological appearance consistent with plasmacytic PTLD. The median time from transplant to diagnosis was 3.7 years (range 8 months–24 years). All patients presented with extranodal and often subcutaneous solid tumors. Laboratory features included elevated LDH and beta‐2 microglobulin levels, monoclonal gammopathy, and EBV positivity of the tumor. Unlike conventional multiple myeloma, patients had normal calcium levels and only mild anemia. Six patients who have completed treatment achieved complete responses with radiation therapy and/or reduction in immunosuppression with two patients now greater than 5 years in continuous complete response. Plasmacytic PTLD, despite its plasmacytic histology, is responsive to conventional therapies used for B‐cell PTLD including reduction in immunosuppression and radiation therapy.     

Clinicopathologic and molecular features of 122 Brazilian cases of nodal and extranodal NK/T-cell lymphoma, nasal type, with EBV subtyping analysis

Extranodal natural killer/T-cell lymphoma, nasal type (NK/TCL) is more prevalent in Asia and in some areas of South and Central America, but it is rarely seen in the United States and Europe. In this study, a series of 122 cases of NK/TCL from Brazil was analyzed with respect to clinicopathologic features. Clinical characteristics and geographic distribution were evaluated in 97 cases of nasal/nasopharyngeal region and 23 cases in extranasal sites including 6 nodal cases. Clinical staging and follow-up information was available in a subset of 21 patients. All cases harbored Epstein-Barr virus (EBV), 95% and 85% expressed cytoplasmic CD3 and CD56, respectively, and all cases were positive for at least 1 marker for cytotoxic granules. The global distribution of EBV subtypes showed predominance of strain subtype A, 89%, and subtype B, 11%. No dual infections were detected. TCR-γ TCR-gene rearrangement was observed in 7 cases; all of them extranodal. Three of TCR-γ(+) cases showed EBV subtype A. Two TCR-γ(+)/CD56(+) cases showed EBV subtype B. Geographic distribution of NK/TCL showed higher frequency in the southeast and northeast regions of Brazil. Striking differences among geographic regions were seen with the vast majority of EBV subtype B (86%) occurring in the south and southeast regions.     

Distinct clonal origin in two cases of Hodgkin's lymphoma variant of Richter's syndrome associated With EBV infection

Occurrence of an aggressive lymphoma in patients with chronic lymphocytic leukemia (CLL), clinically referred to as Richter's syndrome, occasionally manifests as a lymphoproliferation resembling Hodgkin's lymphoma (HL) and often containing the Epstein-Barr virus (EBV). Only a limited number of HL variants have been subject to informative analysis regarding their clonal relationship to the CLL, with evidence of a same clonal origin in some cases and of clonally unrelated neoplasms in other cases. In this paper, we performed a detailed pathologic, virologic, and molecular analysis of two cases of Richter's syndrome with HL features. The first case occurred in a 65-year-old man with a 5-year history of CLL as a mediastinal and supraclavicular mass histologically diagnosed as lymphocyte depleted HL with no background CLL. The second case occurred in a 78-year-old woman with a 4-year history of CLL as an inguinal mass with a composite histologic appearance comprising areas of CLL, areas of CLL with Hodgkin Reed-Sternberg cells, and areas of HL. Both patients had received fludarabine therapy. The HRS cells were CD20-/CD30+/CD15-/J-chain- in case no. 1 and CD20+/-/CD30+/CD15-/J-chain- in case no. 2. In both cases, the Hodgkin's Reed-Sternberg cells (HRS) were positive for type A EBV, and a 30-bp deletion of the LMP-1 gene was detected in case no. 2. Using microdissection and polymerase chain reaction amplification of the immunoglobulin heavy chain gene (IgH) complementarity determining region III of each cell type, we demonstrated a distinct clonal origin for the CLL cells and the HRS in both cases. These cases bring support to the hypothesis that EBV+ HL in CLL patients occurs as unrelated secondary neoplasms most likely as the result of the immune depression associated with CLL and also raise the question of a possible causal role of fludarabine.     

Mucosa-associated lymphoid tissue-type lymphomas occurring in post-transplantation patients

Post-transplantation lymphoproliferative disorders (PTLDs) are usually Epstein-Barr virus (EBV)-associated B-cell lymphoproliferative disorders that vary in their morphologic spectrum. Extranodal marginal zone lymphomas of the mucosa-associated lymphoid tissue-type (MALT-type) have not been considered to be part of this spectrum. The authors encountered five such cases recently. The clinical, histopathologic, and immunophenotypic features are reported. There were three men and two women with a mean age of 51.2 years (range, 48-63 years). Two patients were cardiac transplant recipients, two patients were liver transplant recipients, and the remaining patient was a renal transplant patient. Sites of lymphoma were the stomach in three patients and the parotid gland in two patients. Mean time to the lymphoma was 84 months after transplantation. All patients had morphologic features of low-grade extranodal marginal zone lymphomas of the MALT-type, and Helicobacter pylori was present in all three gastric cases. All patients exhibited the B-cell immunophenotype and were negative for EBV by in situ hybridization. These lymphomas were treated with a variety of modalities, including reduction of immunosuppression, antibiotics, surgical resection, radiation therapy, and chemotherapy. At last follow-up, one patient had developed signet ring adenocarcinoma at 27 months but had no evidence of PTLD, one patient relapsed at 17 months but is alive with stable disease at 24 months, and the remaining patients were alive without disease at 11, 12, and 14 months. Extranodal low-grade MALT-type lymphomas can occur in the post-transplantation setting and generally develop years after transplant. As seen in immunocompetent patients, EBV appears to play no role in the pathogenesis of these lymphomas. These lymphomas appear to have more in common with MALT-type lymphomas in nonimmunocompromised patients than conventional PTLDs, although they occur in "at-risk" patients due to their immunosuppressive therapy. These lymphomas do not appear to be clinically aggressive. Recognition of MALT-type lymphomas in the post-transplantation setting as an indolent disease avoids unnecessary treatment.     

Primary follicular lymphoma of the gastrointestinal tract: a clinical and pathologic study of 26 cases.

Although the gastrointestinal tract represents the most common site of extranodal lymphoma, primary follicular lymphoma of the gastrointestinal tract is an uncommon and poorly defined disease. We report the clinical and pathologic features of 26 patients with primary gastrointestinal follicular lymphoma. Ten of 26 patients (38.5%) were stage IIE, and 16 patients (61.5%) were stage IE. Of the 26 patients, 13 were female and 13 were male. The age range was 26-81 years (median 54.5 years). Abdominal pain was the most common presenting symptom, seen in 12 of 24 patients (50%). Nodularity of the mucosal surface was the most common endoscopic finding, seen in 10 of 14 patients (71.4%). The majority of cases (22 of 26, 84.6%) involved small bowel, four involved colorectum alone, and two involved the ileocecal valve. Within the small bowel the duodenum was the most commonly involved site (10 cases). Transmural involvement by follicular lymphoma was identified in 11 of the 16 patients who underwent surgical resection; five showed involvement of mucosa and submucosa only. The most common histologic grade was grade 1. Thirteen of 26 cases were grade 1, ten grade 2, and three grade 3. Twenty-one of 26 cases showed a predominantly follicular growth pattern, four mixed follicular and diffuse, and one predominantly diffuse. All cases were positive for CD20 and BCL2 and negative for CD3, CD5, CD23, CD43, and cyclin D1. Twenty-four of 26 were positive for CD10. Four of four cases showed cytogenetic or molecular genetic evidence of t(14;18). Initial treatment modalities included surgery plus chemotherapy (nine cases), surgery alone (seven cases), chemotherapy alone (four cases), observation alone (four cases), and chemotherapy and abdominal radiation (one case). One case presented with rectal polyps and was treated with polypectomy. A complete response was observed in 15 of 22 cases that received treatment, and of the 15 cases, five recurred 27-60 months after the initial diagnosis. Recurrence and progression were associated with histologic transformation to diffuse large cell lymphoma in one case. No significant correlation was identified between treatment response and various clinical and pathologic features. Overall, none of the 26 patients died of lymphoma. One patient died of a concomitant pancreatic carcinoma. Of the remaining 25 patients, 14 were disease free and 11 were alive with disease at a mean follow-up of 43 months. The estimated 5-year disease-free survival was 62%, and median disease-free survival was 69 months. The estimated 5-year relapse-free survival was 54%, and the median relapse-free survival was 63 months.     

Adult T-cell lymphoma/leukemia with angioimmunoblastic T-cell lymphomalike features: Report of 11 cases

In adult T-cell lymphoma/leukemia (ATLL), the neoplastic lymphoid cells are usually medium-sized to large, often with pronounced nuclear pleomorphism compatible with the diagnosis of diffuse pleomorphic peripheral T-cell lymphoma. We describe here 11 patients with the rare morphologic variant of ATLL, angioimmunoblastic T-cell lymphoma (AILT)-like type. The examined lymph nodes showed proliferation of high endothelial venules and presence of various infiltrating inflammatory cells including plasma cells and eosinophils. The lymphoma cells were medium-to-large size with clear cytoplasm. These findings were suggestive of AILT. However, immunohistochemical features of AILT, namely, CD10 and CXCL13 expression in lymphoma cells and proliferation of CD21-positive follicular dendritic cells, were not detected. Two cases were CXCR3-positive, whereas 9 expressed CCR4, which are usually positive in ATLL. All patients were positive for antiadult T-cell leukemia/lymphoma-associated antigen, which is a specific antibody for human T-cell lymphotropic virus type-I. Southern blot analysis revealed proviral DNA integration in lymphoma cells in 9 patients. The latter was not evident in the first biopsy of 2 patients but in the second biopsy obtained within several months after the first biopsy revealed definite proviral integration. Almost all patients showed aggressive clinical course and poor survival (median survival: 5 mo). This is the first report of ATLL with AILT-like morphologic features.     

T-cell/histiocyte-rich large B-cell lymphoma: a heterogeneous entity with derivation from germinal center B cells

T-cell/histiocyte-rich large B-cell non-Hodgkin's lymphoma (THRLBCL) is an unusual morphologic variant of diffuse large B-cell lymphoma. We reviewed 30 cases of THRLBCL to evaluate its heterogeneity based on morphologic, immunophenotypic, and genetic features. Cases were classified according to the appearance of the large neoplastic B cells into three morphologic variants: 1) lymphocytic and histiocytic (L&H-like) (resembling the L&H cells of nodular lymphocyte predominance Hodgkin's lymphoma (14 cases); 2) centroblast (or immunoblast)-like (10 cases), and 3) Reed-Sternberg cell-like (resembling the neoplastic cells of classic Hodgkin's lymphoma) (6 cases). We used a panel of immunohistochemical stains, including those with specificity for germinal center B cells: CD20, CD79a, CD30, CD15, epithelial membrane antigen, BCL-2, BCL-6, and CD10. The /JH polymerase chain reaction assay was further performed to investigate a relationship to follicular lymphoma. The results were correlated with Epstein-Barr virus status as determined by staining for latent membrane protein and EBER-1 in situ hybridization. All cases were of B-cell immunophenotype with strong surface CD20 reactivity in the neoplastic large lymphoid cells, although CD79a was more inconsistently and weakly expressed (10 of 17). Nuclear positivity for the BCL-6 protein was detected in the tumor cells in 26 of 29 (90%) cases. However, differences in expression of other antigens were encountered in the histologic subtypes. Epithelial membrane antigen positivity, a feature often seen in nodular lymphocyte predominance Hodgkin's lymphoma, was observed in 11 of 30 (37%) cases and was most commonly seen in cases with L&H cell morphology (8 of 14; 57%). CD30 expression was observed in 9 of 30 (30%) cases but was most frequent in cases with Reed-Sternberg-like morphology (3 of 6 [50%]). CD10 expression was infrequent overall (3 of 29; 10%), with 2 of 3 positive cases identified in the centroblastic group. The overall rarity of positivity for CD10, BCL-2 (3 of 22; 13%), and -2 JH rearrangement (1 of 28; 4%) indicates a lack of connection to follicular lymphoma for all subtypes. The three cases that were negative for BCL-6 protein were LMP-1 positive and EBER-1 positive by in situ hybridization, and 2 of 3 had neoplastic cells with Reed-Sternberg-like morphology. These results demonstrate that although a large proportion of THRLBCL represent tumors of germinal center B cell derivation, they exhibit a diversity of morphologic and immunophenotypic features. A subset of THRLBCL may be related to nodular lymphocyte predominance Hodgkin's lymphoma. A small percentage show features closely resembling classic Hodgkin's lymphoma and could be considered a variant of grey zone lymphoma.     

Epstein-Barr virus-positive B-cell lymphoproliferative disorders arising in immunodeficient patients previously treated with fludarabine for low-grade B-cell neoplasms

We describe five patients with treated low-grade B-cell neoplasms who subsequently developed Epstein-Barr virus (EBV)-positive B-cell lymphoproliferative disorders (BLPDs). The low-grade B-cell neoplasms were B-cell chronic lymphocytic leukemia in four patients and splenic marginal zone lymphoma in one patient. All patients had received treatment with fludarabine for the low-grade B-cell neoplasm, and three had also received Campath-1H. The EBV-BLPDs arose 2-12 months after completion of fludarabine therapy and morphologically resembled the EBV-BLPDs that occur in the setting of iatrogenic immunodeficiency. Molecular genetic studies showed that these lesions were clonally distinct from the low-grade B-cell neoplasm in three of four cases assessed. Two patients did not receive therapy for the EBV-BLPD. The lesions regressed spontaneously in both patients but recurred in one. One patient underwent surgical excision and remains without evidence of the EBV-BLPD. One patient received aggressive multiagent chemotherapy with a complete response initially, but the EBV-BLPD recurred after 12 months. One patient received antiviral therapy and responded completely but died 2 months later of an opportunistic infection. We conclude that patients with low-grade B-cell neoplasms treated with fludarabine, possibly in combination with other immune suppressive agents, may subsequently develop EBV-BLPDs that morphologically resemble other iatrogenic immunodeficiency-associated BLPDs. Most are clonally distinct from the underlying low-grade B-cell neoplasm. A subset of these lesions may regress without systemic therapy.