Eosinophil-rich variant of nodal marginal zone lymphoma: a clinicopathological study of 11 cases

AIMS

Tissue eosinophilia is commonly observed in T-cell and classic Hodgkin lymphomas, but rarely in B-cell lymphomas. Herein, we present the first report of a case series on nodal marginal zone lymphoma (NMZL) with tissue eosinophilia.

METHODS AND RESULTS

All 11 patients in this study had nodal disease at primary presentation. The mean age at diagnosis was 64 years. The mean follow-up period was 39 months, and all patients were alive. Nine of the 11 patients (82%) showed no recurrence, but the other two patients experienced recurrence in the lymph nodes or skin. Marked eosinophilic infiltration was observed in all biopsied lymph nodes. Nine of the 11 patients had a preserved nodular architecture with expanded interfollicular areas. The other two patients showed diffuse lymphoma cell infiltration with effacement of nodal architecture. One of them was diagnosed as having diffuse large B-cell lymphoma transformed from NMZL because large cells accounted for >50% of the lymphoma cells and formed sheet-like patterns. Cells were positive for CD20 and BCL2 and negative for CD5, CD10, and BCL6. Some patients showed myeloid cell nuclear differentiation antigen (MNDA) positivity. All patients showed B-cell monoclonality via flow cytometry, southern blotting, and/or polymerase chain reaction (PCR).

CONCLUSION

All patients showed distinctive morphological features and could be misdiagnosed with peripheral T-cell lymphoma due to their eosinophil-rich backgrounds. The predominance of B cells, absence of histiocytes, and high endothelial venules in the interfollicular areas are key factors for diagnosis. B-cell monoclonality is the most reliable evidence of differentiation. We designated this type of lymphoma as an eosinophil-rich variant of NMZL.

Long-Term Observation of the Progression From Nodal Marginal Zone Lymphoma to Diffuse Large B-Cell Lymphoma in a Dog

A 4-year and 10-month old female Pembroke Welsh Corgi presented with an enlarged right popliteal lymph node, and a histopathological diagnosis of nodal marginal zone lymphoma (nMZL) was made. After resection of the lymph node, follow-up observation was continued without chemotherapy. At 22 months after initial presentation, the dog developed enlargement of peripheral lymph nodes, and the histopathological diagnosis was late-stage nMZL. Multidrug chemotherapy induced clinical complete remission, but the tumor relapsed with enlargement of peripheral and abdominal lymph nodes 42 months after initial presentation. Second-round multidrug chemotherapy induced complete clinical remission again; however, the tumor relapsed with lymphadenopathy 47 months after initial presentation. The dog died 59 months after initial presentation, and postmortem examination revealed generalized lymphadenopathy; the histopathological diagnosis was diffuse large B-cell lymphoma (DLBCL). Polymerase chain reaction for antigen receptor gene rearrangements revealed that the nMZL and DLBCL samples were derived from the same B-lymphocyte clone.

Marginal zone B-cell lymphoma: lessons from Western and Eastern diagnostic approaches

Marginal zone B-cell lymphomas (MZLs) are a group of clinically indolent B-cell lymphomas postulated to derive from memory B lymphocytes in the 'marginal zone' of secondary lymphoid tissue. Today, MZL is recognised as a nosological umbrella term encompassing distinct entities with some shared phenotypic and genotypic features, including extranodal marginal zone B-cell lymphoma (EMZL) or mucosa-associated lymphoid tissue (MALT) lymphoma, splenic MZL, and nodal MZL, accounting for approximately 70%, 20%, and 10% of MZLs, respectively. These lymphomas share some phenotypic and genotypic features and have some variants and related provisional diseases, but are different in regards to their clinical and molecular characteristics. In addition, they are frequently associated with chronic antigenic stimulation represented either by infectious agents, particularly bacteria and viruses, or autoimmune diseases as exemplified by Sjögren syndrome, Hashimoto thyroiditis, and newly recognised IgG4-related disease. Furthermore, several chromosomal translocations have been identified in EMZL. In this review, we will focus on the updated histopathological criteria and the main problems with differential diagnoses in order to aid the diagnostic approach in our routine practice.

Recurrent mutations in genes involved in nuclear factor-κB signalling in nodal marginal zone lymphoma-diagnostic and therapeutic implications

AIMS

To investigate the spectrum of mutations in 20 genes involved in B-cell receptor and/or Toll-like receptor signalling resulting in activation of nuclear factor-κB (NF-κB) in 20 nodal marginal zone lymphomas (NMZLs), 20 follicular lymphomas (FLs), and 11 cases of B-cell lymphoma, unclassifiable (BCL-u).

METHODS AND RESULTS

Nodal marginal zone lymphomas were diagnosed according to strict criteria, including the expression of at least one putative marginal zone marker (MNDA and/or IRTA1). Cases that showed features of NMZL but did not fulfil all criteria were included as BCL-u. All FLs were required to have a BCL2 rearrangement. Mutations were found in: nine NMZLs, with recurrent mutations in TNFAIP3 and CD79B; 12 FLs, with recurrent mutations in TNFRSF14, TNFAIP3, and CARD11; and five cases of BCL-u, with recurrent mutations in TNFRSF14. TNFRSF14 mutations were present in FL and BCL-u, but not in any of the NMZLs. In the BCL-u group, TNFRSF14 mutations clustered with a FL immunophenotype.

CONCLUSIONS

These results suggest that TNFRSF14 mutations point towards a diagnosis of FL, and can be used in the sometimes difficult distinction between NMZL and FL, but to apply this in diagnostics would require confirmation in an independent cohort. In addition, the presence or absence of specific mutations in pathways converging on NF-κB could be important for decisions regarding targeted treatment.

The bendamustine plus rituximab regimen is active against primary nodal marginal zone B-cell lymphoma

Primary nodal marginal zone lymphoma (NMZL) is a rare disease. There is no current consensus on how to treat it. The bendamustine plus rituximab (BR) regimen is effective for the treatment of follicular and other indolent lymphomas, but its efficacy in NMZL is not known. We analyzed the outcome of 14 patients diagnosed with NMZL (median age 67 years) who were treated with 375 mg/m² of rituximab on day 1 and 90 mg/m² of bendamustine on days 1 and 2. The overall and complete response rates were 93% and 71%, respectively. Major toxicity (grade 3/4 neutropenia) occurred in 5% of treatment courses. After a median follow-up of 22 months (range: 18-55), the overall survival and the free survival rates were 100% and 93%, respectively. None of the patients showing a complete or partial response developed secondary myelodysplastic syndrome/acute myeloid leukemia. Bendamustine plus rituximab was found to be an active and well-tolerated regimen leading to the rapid control of disease.

Childhood nodal marginal zone lymphoma with unusual clinicopathologic and cytogenetic features for the pediatric variant: a case report

Nodal marginal zone lymphoma (NMZL) is a B-cell lymphoma that shares morphologic and immunophenotypic features with extranodal and splenic marginal zone lymphomas but lacks extranodal or splenic involvement at presentation. NMZL occurs mostly in adults with no sex predilection, at advanced stage (III or IV), with frequent relapses and a high incidence of tumoral genetic abnormalities including trisomies 3 and 18 and gain of 7q. Pediatric NMZL, however, is a rare but distinct variant of NMZL with characteristic features including male predominance, asymptomatic and localized (stage I) disease, low relapse rates with excellent outcomes, and a lower incidence of essentially similar genetic aberrations compared to adult NMZL. Here we describe a unique case of childhood NMZL with unusual clinicopathologic features for the pediatric variant including generalized lymphadenopathy, high-stage disease with persistence after therapy, unusual immunophenotype (CD5, CD23, and BCL6 positive), and unique chromosomal abnormalities including monosomy 20 and add(10)(p11.2).

Disparate survival outcomes after front-line chemoimmunotherapy in older patients with follicular, nodal marginal zone and small lymphocytic lymphoma

Using Surveillance, Epidemiology and End Results (SEER)-Medicare data (1996-2010), we compared survival and toxicity outcomes in 6993 patients older than 65 years with follicular (FL), nodal marginal zone (NMZL) and small lymphocytic lymphoma (SLL) receiving front-line therapy with rituximab (R), RCHOP (R, cyclophosphamide, doxorubicin, vincristine, prednisone), RCVP (R, cyclophosphamide, vincristine, prednisone) or R-fludarabine-containing regimens within 3 years from diagnosis. We demonstrated significant heterogeneity by histology after various regimens in multivariable survival models. Compared with RCHOP, overall survival was inferior with fludarabine-based regimens in FL (hazard ratio [HR] 1.53, p = 0.0001) and NMZL (HR 1.88, p = 0.0018). Conversely, in SLL outcomes were similar with any regimen. In NMZL and SLL, survival was not significantly different after single-agent R compared with multi-agent combinations. Choice of front-line chemotherapy may thus impact survival in older patients with indolent lymphomas, and heterogeneity by histology should be accounted for in clinical trials.

Radiotherapy of follicular lymphoma: updated role and new rules

Radiation is established as one of the most powerful, highly effective treatments for non-Hodgkin lymphoma (NHL). Unfortunately, in recent years the medical oncology community has improperly underutilized radiotherapy (RT) in the management of NHL. Replacing RT with longer chemotherapy and/or immunotherapy may not necessarily be a good alternative approach and may lead to suboptimal outcome and more toxicity, particularly in patients with localized disease. Some misconceptions regarding the use of RT emanated from the ways RT has been utilized in the past-as a single therapy and in high doses and large fields. Major developments in imaging technology, radiation planning concepts, and RT precision and delivery have been revolutionized RT for NHL over the past two decades. Modern proper administration should result with very minimal acute or late side effects. Some of the controversial issues of the use of RT borrowed from Hodgkin lymphoma, such as risk of secondary tumors, are irrelevant to patients with NHL but cause unnecessary patient and physician scare. Many lymphoma types are notoriously sensitive to RT, especially the indolent types. When localized, like in most marginal zone lymphoma (MZL) and almost a third of follicular lymphomas (FL), RT is potentially curative, even with low dose and small volumes. In more aggressive lymphomas, RT often is an effective consolidation after chemotherapy in complete or even incomplete responders. It also is an important component of salvage and palliation. In older patients, RT is particularly valuable, because chemotherapy tolerance and salvage options may be limited. The International Lymphoma Radiation Oncology Group (ILROG) developed and published modern guidelines for using RT in NHL, including FL. The guidelines emphasize the new concept of RT field: involved site radiotherapy (ISRT). These modern ILROG principles and several relevant studies that looked into the proper integration of RT in the management of NHL patients are the focus of this manuscript.

Nodal reactive and neoplastic proliferation of monocytoid and marginal zone B cells: an immunoarchitectural and molecular study highlighting the relevance of IRTA1 and T-bet as positive markers

AIMS

Marginal zone B cells (MZCs) and monocytoid B cells (MBCs) appear to be related lymphoid cells that take part in reactive and neoplastic marginal zone proliferations. These lesions are not yet well characterized, and the aim of this study was to find better diagnostic criteria for them.

METHODS AND RESULTS

We analysed 60 nodal lesions with MBC and/or MZC proliferation for their morphological, immunophenotypic, molecular genetic and IG gene rearrangement features. On the basis of the results of the rearrangement assay and immunoglobulin light chain restriction, the lesions were divided into reactive and neoplastic groups. Among the neoplastic lesions, polymorphic and monomorphic subgroups emerged. All reactive lesions had morphological features of the polymorphic subgroup. By immunohistochemistry, IRTA1 and/or T-bet expression was found in all reactive lesions and in 90% of neoplastic lesions.

CONCLUSIONS

IRTA1 and T-bet are positive markers for the identification of MZC/MBC proliferations, and thus for the diagnosis of nodal marginal zone lymphoma (NMZL). Polymorphic and monomorphic subgroups of NMZL could be distinguished. Most morphological and immunophenotypic patterns in reactive and neoplastic nodal expansions of MZCs and MBCs overlapped. Therefore, PCR clonality assay of the immunoglobulin heavy and light chain gene loci is the most reliable method for their differentiation.