Methylation profiling of mediastinal gray zone lymphoma reveals a distinctive signature with elements shared by classical Hodgkin's lymphoma and primary mediastinal large B-cell lymphoma

Background

Mediastinal gray zone lymphoma is a newly recognized entity with transitional morphological and immunophenotypic features between the nodular sclerosis subtype of Hodgkin’s lymphoma and primary mediastinal large B-cell lymphoma. Diagnostic criteria for mediastinal gray zone lymphoma are still challenging, and the optimal therapy is as yet undetermined. Epigenetic changes have been implicated in the loss of the B-cell program in classical Hodgkin’s lymphoma, and might provide a basis for the immunophenotypic alterations seen in mediastinal gray zone lymphoma.

Design and Methods

We performed a large-scale DNA methylation analysis of microdissected tumor cells to investigate the biological underpinnings of mediastinal gray zone lymphoma and its association with the related entities classical Hodgkin’s lymphoma and primary mediastinal large B-cell lymphoma, making comparisons with the presumptively less related diffuse large B-cell lymphoma.

Results

Principal component analysis demonstrated that mediastinal gray zone lymphoma has a distinct epigenetic profile intermediate between classical Hodgkin’s lymphoma and primary mediastinal large B-cell lymphoma but remarkably different from that of diffuse large B-cell lymphoma. Analysis of common hypo- and hypermethylated CpG targets in mediastinal gray zone lymphoma, classical Hodgkin’s lymphoma, primary mediastinal large B-cell lymphoma and diffuse large B-cell lymphoma was performed and confirmed the findings of the principal component analysis. Based on the epigenetic profiles we were able to establish class prediction models utilizing genes such as HOXA5, MMP9, EPHA7 and DAPK1 which could distinguish between mediastinal gray zone lymphoma, classical Hodgkin’s lymphoma and primary mediastinal large B-cell lymphoma with a final combined prediction of 100%.

Conclusions

Our data confirm a close relationship between mediastinal gray zone lymphoma and both classical Hodgkin’s lymphoma and primary mediastinal large B-cell lymphoma. However, important differences were observed as well, allowing a clear distinction from both parent entities. Thus, mediastinal gray zone lymphoma cannot be assigned to either classical Hodgkin’s lymphoma or primary mediastinal large B-cell lymphoma, validating the decision to create an intermediate category in the World Health Organization classification.     

Primary low-grade B-cell lymphoma of the urinary bladder: case report and literature review

The first recorded case of lymphoma of the bladder was reported by Eve and Chaffey in 1885. Malignant lymphoma of the bladder can be classified into one of three different clinical groups: 1) Primary lymphoma localized to the bladder; 2) Lymphoma presenting in the bladder as the first sign of disseminated disease (non-localized lymphoma); 3) Recurrent bladder involvement by lymphoma in patients with a history of malignant lymphoma (secondary lymphoma). Primary extranodal marginal zone lymphoma of mucosa associated lymphoid tissue (MALT type) of the urinary bladder, first described by Kempton et al in 1990, is the most common primary bladder lymphoma and associated with an excellent prognosis. We present a patient with gross hematuria who was found to have a primary bladder lymphoma and review the relevant literature.     

Molecular pathophysiology of indolent lymphoma

Indolent lymphomas are a markedly heterogeneous group of lymphoproliferative disorders including B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma, lymphoplasmacytoid lymphoma, follicular lymphoma, mantle cell lymphoma and mucosa-associated lymphoid tissue (MALT) lymphoma. The molecular pathophysiology of indolent lymphoma is characterized by distinct genetic pathways which selectively associate with different clinico-pathologic categories of the disease. At diagnosis, B-cell chronic lymphocytic leukemia frequently display deletions of 13q14, trisomy 12 and alterations of the ATM gene, whereas evolution to Richter's syndrome is associated with disruption of p53. Lymphoplasmacytoid lymphoma carries t(9;14) (p13;q32) in approximately 50% of cases, leading to the deregulated expression of the PAX-5 gene. Follicular lymphoma consistently harbors rearrangement of BCL-2. With time, a fraction of follicular lymphoma accumulates mutations of p53 and of p16 and evolves into a high grade lymphoma. MALT-lymphoma frequently associates with alterations of API2/MLT and, in some cases, of p53, BCL-6 and BCL-10. Studies of genotypic and phenotypic markers of histogenesis have shown that mantle cell lymphoma and a fraction of B-CLL/SLL derive from naive B-cells, whereas follicular lymphoma, lymphoplasmacytoid lymphoma and MALT-lymphoma originate from germinal center (GC) or post-GC B-cells. The identification of distinct genetic categories of indolent lymphoma may help in the therapeutic stratification of these disorders. In addition, genetic lesions of indolent lymphoma provide useful molecular markers for disease monitoring by high sensitivity techniques.     

Lymphome non hodgkinien gastrique 7 ans après un lymphome hodgkinien. A propos d’un cas

After treatment of Hodgkin lymphoma (HL), several types of tumors can arise like non Hodgkin lymphoma. We report the case of a diffuse large B cell lymphoma diagnosed in a patient treated 7 years before for a non Hogdkin lymphoma. Through our observation and a review of the literature, we specify the characteristics of non Hogdkin lymphoma following a treated Hodgkin lymphoma.     

Dissecting the gray zone between follicular lymphoma and marginal zone lymphoma using morphological and genetic features

Nodal marginal zone lymphoma is a poorly defined entity in the World Health Organization classification, based largely on criteria of exclusion and the diagnosis often remains subjective. Follicular lymphoma lacking t(14;18) has similar characteristics which results in a major potential diagnostic overlap which this study aims to dissect. Four subgroups of lymphoma samples (n=56) were analyzed with high-resolution array comparative genome hybridization: nodal marginal zone lymphoma, t(14;18)-negative follicular lymphoma, localized t(14:18)-positive follicular lymphoma and disseminated t(14;18)-positive follicular lymphoma. Gains on chromosomes 7, 8 and 12 were observed in all subgroups. The mean number of aberrations was higher in disseminated t(14;18)-positive follicular lymphoma than in localized t(14:18)-positive follicular lymphoma (P<0.01) and the majority of alterations in localized t(14:18)-positive follicular lymphoma were also found in disseminated t(14;18)-positive follicular lymphoma. Nodal marginal zone lymphoma was marked by 3q gains with amplifications of four genes. A different overall pattern of aberrations was seen in t(14;18)-negative follicular lymphoma compared to t(14;18)-positive follicular lymphoma. t(14;18)-negative follicular lymphoma is characterized by specific (focal) gains on chromosome 3, as observed in nodal marginal zone lymphoma. Our results support the notion that localized t(14:18)-positive follicular lymphoma represents an early phase of disseminated t(14;18)-positive follicular lymphoma. t(14;18)-negative follicular lymphoma bears aberrations that are more like those in nodal marginal zone lymphoma, suggesting a relation between these groups.     

Lymphomes spléniques : diagnostic et prise en charge

Some common clinical situations, such as splenomegaly or lymphocytosis, or less common, such as autoimmune hemolytic anemia, cold agglutinin disease, or cryoglobulinemia can lead to the diagnosis of splenic lymphoma. Splenic lymphoma is rare, mainly of non-hodgkinian origin, encompassing very different hematological entities in their clinical and biological presentation from an aggressive form such as hepato-splenic lymphoma to indolent B-cell lymphoma not requiring treatment such as marginal zone lymphoma, the most frequent form of splenic lymphoma. These entities can be challenging to diagnose and differentiate. This review presents different clinical and biological manifestations suspicious of splenic lymphoma and proposes a diagnosis work-up. We extended the strict definition of splenic lymphoma (lymphoma exclusively involving the spleen) to lymphoma thant can be revealed by a splenomegaly and we discuss the differential diagnosis of splenomegaly.     

Management of Lymphomas: Consensus Document 2018 by an Indian Expert Group

The clinical course of lymphoma depends on the indolent or aggressive nature of the disease. Hence, the optimal management of lymphoma needs a correct diagnosis and classification as B cell, T-cell or natural killer (NK)/T-cell as well as indolent or high-grade type lymphoma. The current consensus statement, developed by experts in the field across India, is intended to help healthcare professionals manage lymphomas in adults over 18 years of age. However, it should be noted that the information provided may not be appropriate to all patients and individual patient circumstances may dictate alternative approaches. The consensus statement discusses the diagnosis, staging and prognosis applicable to all subtypes of lymphoma, and detailed treatment regimens for specific entities of lymphoma including diffuse large B-cell lymphoma, Hodgkin’s lymphoma, follicular lymphoma, T-cell lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma, Burkitt’s lymphoma, and anaplastic large cell lymphoma.     

Malignant lymphoma of the rectum

Malignant lymphoma involving the rectum is rare. Of 61 patients with malignant lymphoma involving the rectum seen at the Mayo Clinic between 1950 and 1977, 49 had extensive lymphoma with secondary involvement of the rectum, and 12 had lymphoma confined to the rectum. Patients with widespread lymphoma were treated with radiation, chemotherapy, or both. Of the 12 patients with lymphoma confined to the rectum, five had surgical excision and seven were treated nonoperatively; the overall five-year survival was 20 percent. Patients with widespread lymphoma had a five-year survival of 15 percent. Patients with lymphoma confined to the rectum had a five-year survival of 50 percent, and patients who had surgical excision did better than those treated nonoperatively.     

Cooperative function of CCR7 and lymphotoxin in the formation of a lymphoma-permissive niche within murine secondary lymphoid organs

Lymphoma cell survival and progression are putatively dependent on a specific microanatomic localization within secondary lymphoid organs. Despite compelling data correlating homeostatic chemokine receptor expression and human lymphoma pathogenesis, genetic models that either mimic lymphoma dissemination or dissect a crosstalk of lymphoma and stromal cells are missing. Applying the genetically tractable Eμ-Myc transgenic mouse model, we show that the chemokine receptor CCR7 regulates Eμ-Myc lymphoma homing to lymph nodes and distinctive microanatomic sites of the spleen. CCR7-controlled access of lymphoma cells to the splenic T-cell zone led to a significant survival advantage compared with CCR7-deficient lymphoma cells, which were excluded from this zone. Within the niche, lymphoma cells stimulated a reciprocal cross-talk with gp38(+) fibroblastic reticular cells. This reciprocal cooperation program was mediated by lymphoma B cell-presented lymphotoxin, which acted on lymphotoxin-β-receptor-bearing stromal cells followed by alteration of stromal cellular composition. Cross-talk inhibition by lymphotoxin-α deletion and using a lymphotoxin-β receptor-immunoglobulin fusion protein impaired lymphoma growth. Thus, abrogation of CCR7-governed migration and of sustained lymphotoxin signaling could provide new targets in lymphoma therapy.     

A prospective study of 728 cases of non-Hodgkin lymphoma from a single laboratory in Shanghai,China

The frequency of subtypes of lymphoid neoplasms was determined in a prospective series of 831 patients presenting at 29 Shanghai hospitals over a 4-year period. Diagnosis and classification was established in a single laboratory according to the 2001 WHO classification system. The frequency of non-Hodgkin lymphoma was 87.6% (n = 728) and Hodgkin lymphoma was 12.4% (n = 103). The most prevalent NHL subtypes diagnosed using WHO criteria were diffuse large B cell lymphoma (DLBCL), precursor B lymphoblastic leukemia/lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Although a low incidence has been reported in some Asian populations, CLL/SLL was commonly encountered, indicating that chronic lymphoid neoplasms are not rare in Shanghai. Consistent with previous reports, our findings indicate a decrease in the frequency of follicular lymphoma and an increase in T cell neoplasms compared to the West. Precursor T lymphoblastic leukemia/lymphoma, anaplastic large T cell lymphoma, aggressive NK cell leukemia, angioimmunoblastic T cell lymphoma and peripheral T cell lymphoma were prominent subtypes of T cell NHL.     

T cell lymphoma of the thyroid gland in celiac disease.

Previous studies have reported the association between celiac disease and T cell lymphoma of the intestine as well as hepatosplenic lymphoma, a specialized peripheral type of T cell lymphoma. In this report, a 66-year-old woman with dermatitis herpetiformis and biopsy-defined celiac disease developed a thyroid mass that proved to be a T cell lymphoma. A T cell lymphoma in the setting of celiac disease appears to be unique. The thyroid gland, due to its shared embryological developmental links with the gastrointestinal tract, is possibly another site of extranodal lymphoma linked to celiac disease.     

Simultaneous phenotypically distinct but clonally identical mucosa-associated lymphoid tissue and follicular lymphoma in a patient with Sj?gren's syndrome.

A 44-year-old woman with a 12-year history of Sj?gren's syndrome (SS) developed a low-grade mucosa-associated lymphoid tissue (MALT) lymphoma in the parotid gland. Two years later, she presented with generalized lymphadenopathy and hepatosplenomegaly and a follicular lymphoma was diagnosed. To investigate the relationship of the two histologically distinct lymphomas, we re-examined their histology and immunophenotype and studied the lymphomatous tissue from the parotid, cervical lymph node, and spleen using molecular genetic methods. Histologic and immunophenotypic studies confirmed the previous diagnoses and also identified a previously unnoticed focus of follicular lymphoma in the second parotid gland biopsy. Polymerase chain reaction (PCR) amplification of the rearranged Ig heavy-chain gene showed the same sized dominant product in the MALT lymphoma and the follicular lymphoma. Similarly, PCR analysis of the t(14:18) translocation yielded an identical sized band from both MALT and follicular lymphoma. Cloning and sequencing of the Ig PCR products showed an identical CDR3 sequence from each lesion, indicating a common clonal lineage. The follicular lymphoma of the parotid gland lymph node and the follicular lymphoma of the spleen showed an identical mutation signature to that of the salivary gland MALT lymphoma. We propose that follicular lymphoma in the parotid gland lymph node may have resulted from colonization of lymphoid follicles by MALT lymphoma cells, following which the tumor cells were induced to express a follicular lymphoma phenotype, due to Bcl-2 overexpression caused by t(14;18), leading to a change in clinical behavior resulting in rapid widespread dissemination of disease. These observations suggest that the distinct phenotypes of low-grade B-cell lymphomas may be the consequence of interplay between genetic and local microenvironmental factors.     

Morphologic diagnosis of leukaemic B-lymphoproliferative disorders and the role of cyclin D1 expression

PURPOSE: This study analysed the morphologic differences between leukaemic mantle cell lymphoma, follicular lymphoma, nodal marginal zone lymphoma, and diffuse large B-cell lymphoma in peripheral blood. Additionally, we investigated the role of cyclin D1 expression in B-lymphoproliferative disorders. METHODS: The morphologic analysis of the leukaemic cells was performed on cytocentrifuge preparations after separation of mononuclear cells from peripheral blood using a Ficoll-Hypaque density gradient. Cyclin D1 protein expression was studied with the catalyzed signal amplification system. The expression of other markers (CD5, CD23, light chain immunoglobulins) was analysed by the APAAP method. RESULTS: We describe in detail the morphology of the lymphoma cells in eight patients with mantle cell lymphoma, six patients with follicular lymphoma, 11 patients with nodal marginal zone lymphoma, and seven patients with diffuse large B-cell lymphoma. The morphological distinction between these lymphoma cells is a challenge for the haematologist. The investigation of cytocentrifuge preparations of mononuclear cells allows the detection of lymphoma cells also in cases with nondiagnostic white cell differential. Additionally, the immunotype (light chain restriction, CD5, CD23, and cyclin D1) of 108 patients with leukaemic B-lymphoproliferative disorders was studied. Diffuse nuclear expression of cyclin D1 protein (>20%) was specific for mantle cell lymphoma. However, only 6/8 patients showed cyclin-D1 positivity. CONCLUSIONS: The morphologic analysis of lymphoma cells in cytocentrifuge preparations of mononuclear leukocytes in combination with immunocytochemical investigation allows the detection of mantle cells, centrocytes of follicular lymphoma, marginal zone cells, and cells of the diffuse large B-cell lymphoma in peripheral blood. The positivity of cyclin D1 protein improves the differentiation of mantle cells from other lymphoma cells.     

Primary adrenal non-Hodgkin's lymphoma: report of two cases

Primary adrenal lymphoma is very rare. It is characterized by a high incidence of bilateral adrenal involvement of diffuse large B-cell lymphoma. It can be diagnosed with endocrine evaluation, imaging studies and histopathological examination. We present two cases of primary adrenal lymphoma. One is a 74-year-old female patient with right primary adrenal lymphoma and the other is a 62-year-old male patient with bilateral primary adrenal lymphoma associated with normal adrenal function. In both cases, radiological features led to an initial misdiagnosis. The surgical exploration demonstrated masses invading the retroperitoneal space, and the biopsy revealed diffuse large B-cell lymphoma. In conclusion, primary adrenal lymphoma should be kept in mind in the differential diagnosis of adrenal masses. In cases of suspicious primary adrenal lymphoma, percutaneous computerized tomography or ultrasonography-guided needle biopsy can help to avoid unnecessary surgeries.     

颈部复合性淋巴瘤临床病理特征及文献复习

目的:探讨罕见的复合性淋巴瘤的临床病理特征。方法:采用形态学、免疫组织化学及分子遗传学方法对1例颈部复合性的黏膜相关淋巴组织淋巴瘤及外周T细胞淋巴瘤进行临床病理分析并复习文献。结果:本例复合性B与T细胞淋巴瘤在形态上有黏膜相关淋巴组织淋巴瘤和外周T细胞淋巴瘤的特征,且IgH和TCR基因重排。结论:复合性淋巴瘤罕见,诊断需结合形态、免疫表型和分子遗传学特征。     

Primary CNS lymphoma other than DLBCL: a descriptive analysis of clinical features and treatment outcomes

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.     

Hepatitis C virus infection and primary hepatic large B-cell lymphoma: a non-fortuitous association. Case report and review of literature

We report a case of hepatitis C virus infection in association with primary hepatic large B-cell non-Hodgkin's lymphoma. Primary hepatic non-Hodgkin's lymphoma is a rare disease. Association of hepatitis C virus infection with primary hepatic B-cell non-hodgkin's lymphoma is probably not fortuitous. Indeed, in case of primary hepatic non-hodgkin's lymphoma' patients are often hepatitis C virus positive. Moreover, several studies have reported a high prevalence of chronic hepatitis C virus infection among patients with B-cell non-Hodgkin's lymphoma whatever the localization of the lymphoma. A recent study found a high rate of remission of a splenic form of lymphoma after treatment of hepatitis C virus infection. Our case report confirms the hypothesis of a key role of hepatitis C virus in the pathogenesis of various forms of B-cell lymphoproliferative disorders and in particular in primary hepatic lymphoma.     

Two cases of discordant lymphomas consisting of MALT lymphoma and follicular lymphoma

We report here rare cases of discordant lymphoma consisting of MALT lymphoma and follicular lymphoma. Case 1: A 53-year-old woman was diagnosed with MALT lymphoma of the left parotid gland and follicular lymphoma of the duodenum and small intestine. Case 2: A 38-year-old woman was diagnosed with MALT lymphoma of the intestine and follicular lymphoma of the duodenum and bone marrow. Recently, it has been suggested that duodenal follicular lymphoma has intermediate characteristics of nodal follicular lymphoma and MALT lymphoma. It is interesting that both of these cases demonstrated duodenal follicular lymphoma. These cases suggest that MALT lymphoma and duodenal follicular lymphoma share some common pathological condition.     

Monoclonal gammopathy after low-grade MALT lymphoma: evidence for a second neoplasm

We report the case of a patient with lymphoma of the salivary gland, at first diagnosed as lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) but later found to infiltrate the bone marrow. At diagnosis, the patient had a polyclonal increase of gamma-globulins. Five years after initial diagnosis, the patient presented with monoclonal gammopathy and infiltration of the bone marrow with neoplastic cells. Initially, the patient had received chemotherapy with different protocols (including etoposide, cyclophosphamide, fludarabin, methotrexate, and vincristine), none of which induced a lasting response. Therapy with rituximab (chimeric anti-CD20 monoclonal antibody) finally led to partial remission. Eighteen months after rituximab, progressive lymphoma in the abdomen and a monoclonal gammopathy developed. The bone marrow showed infiltration by lymphoplasmacytoid cells (monoclonal expression of the light-chain type lambda, positive for CD20, heterogeneous expression of CD45). The patient achieved another short clinical response with 4 cycles of the CHOP-protocol, but soon the lymphoma progressed again. Five years and 8 months after the initial diagnosis, the patient died from septicemia and progressive lymphoma. By polymerase chain reaction (PCR) for the IgH gene it was shown that lymphoma cells were initially oligoclonal in the salivary gland and, later, biclonal in the bone marrow. Sequencing of two bands of apparently same length showed that these manifestations of lymphoma were not identical. Taken together, our data show that the initial low-grade oligoclonal MALT lymphoma was no longer present and a more aggressive biclonal lymphoma with plasmacytoid differentiation had developed. The new lymphoma was clonally distinct and produced high amounts of monoclonal IgG lambda by immunoelectrophoresis. The relationship of the second lymphoma to the initial MALT lymphoma is discussed.