Thymic extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue: a clinicopathological and genetic analysis of six cases.
ABSTRACT We investigated six new cases of primary thymic extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) to further characterize the clinicopathological and genetic features. The male to female ratio was 1:1. One female patient had suffered from systemic lupus erythematosus. Another female patient was diagnosed with rheumatoid arthritis after thymectomy. One patient had a concurrent tumor in the eyelid. Radiologically, all tumors were located in the prevascular space and presented as asymmetric heterogeneously enhanced cystic and solid masses. MALT1, BCL10 or IGH translocations and trisomy 18 were not observed in any cases by fluorescence in situ hybridization (FISH) analysis. Trisomy 3 was detected in one patient and another showed a TNFAIP3/A20 deletion. Meta-analysis (n = 51) including the present and previously reported cases revealed that the prevalence of autoimmunity was much lower in males with thymic MALT lymphoma compared to females (33% vs. 87%, p = 0.001). Additionally, the average age of females or patients with autoimmunity was about 10 years younger than that of males or patients without autoimmunity (p = 0.003 and p = 0.008, respectively). In summary, thymic MALT lymphoma arising without underlying autoimmunity frequently involves males or older patients. Trisomy 3 and an A20 deletion might play a role in the pathogenesis of thymic MALT lymphoma.
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ABSTRACT: INTRODUCTION: Thymic mucosa-associated lymphoid tissue (MALT) lymphoma involving lymph nodes is quite rare with only 13 previous cases reported in the literature. PRESENTATION OF CASE: The 33-years-old female was referred to our department for the investigation of abnormalities on computed tomographic (CT) scans. CT scans showed a 9-cm×3-cm mass composed of a mixture of soft tissue and fat at the anterior mediastinum with lymphadenopathy in the neck, axillary and mediastinal regions. She was underwent complete surgical resection of the mass with regional lymph node dissection through a median sternotomy. Histological examination of the surgical specimens confirmed the diagnosis of MALT lymphoma arising in the thymus with nodal metastasis. She achieved complete remission after postoperative rituximab combined chemotherapy. DISCUSSION: Thymic MALT lymphoma occurs most frequently in Asian female aged 40-60 years and commonly appears anterior mediastinal masses on CT scans. The excised tissue is necessary to confirm the accurate histological diagnosis. The disease usually remains localized for a long time, making local surgical resection highly effective. However, when the lymph nodes are involved, effective treatment approaches of the disease is still undefined. CONCLUSION: We report a case of thymic MALT lymphoma involving lymph nodes, in which the patient was successfully treated with primary site resection with regional lymph node dissection followed by rituximab combined chemotherapy. Surgery provided not only a useful approach for collecting tissue for an accurate histological diagnosis, but also an effective local treatment, even in the case of advanced-stage thymic MALT lymphoma.International journal of surgery case reports. 12/2012; 4(3):250-252.
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ABSTRACT: Abstract We analyzed clinicopathologic implication of A20/Tumor necrosis factor alpha-induced protein 3 deletion in diffuse large B-cell lymphoma (DLBCL) using fluorescence in situ hybridization, according to germinal center B-cell (GCB) vs. non-GCB/activated B-cell (ABC) phenotypes and rituximab treatment. Excluding primary CNS and EBV-positive lymphomas, 134 DLBCLs were analyzed. A20 was deleted in 23.1% (31/134) of DLBCLs containing 21.6% (29/134) of monoallelic and 1.5% (2/134) of biallelic deletion with no predilection for GCB vs. non-GCB/ABC. In univariate analysis, A20 deletion was marginally associated with good prognosis in rituximab-treated subgroup (n=109; p=0.0454), non-gastrointestinal lymphoma (n=108; p=0.0320) and nodal lymphoma (n=46; p=0.0411). In multivariate analysis in rituximab-treated DLBCL, MUM1 and international prognostic index (IPI) were independent prognostic factors (p=0.021 [IPI]; p=009 [MUM1]) with a marginal good prognostic effect for A20 deletion (p=0.047). Taken together, A20 deletion was observed in similar frequencies in GCB and non-GCB/ABC, and was not a poor prognostic factor in DLBCL.Leukemia & lymphoma 01/2013; · 2.61 Impact Factor
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ABSTRACT: Abstract Although rare, thymic mucosa-associated lymphoid tissue (MALT) lymphoma is considered to be a distinct clinicopathological entity. Using a methylation-specific polymerase chain reaction, we analyzed thymic MALT lymphomas (n=18) for their methylation of the following seven tumor suppressor genes: DAPK1, p16(INK4A), p14(ARF), CDH1, RARB, TIMP3, and MGMT. Reactive lymph nodes (n=16) were used as a control. Of the seven genes examined, thymic MALT lymphomas had an increased number of genes that were methylated (2.9 genes) as compared with reactive lymph nodes (0.63, p=0.0003). In particular, thymic MALT lymphomas showed a frequent methylation of DAPK1, CDH1, TIMP3, and p14(ARF). In addition, gene methylation of the p14(ARF) was associated with a larger tumor size while that of the other three genes was not associated with any clinicopathological features examined. This study suggests that methylation of tumor suppressor genes may play an important role in thymic MALT lymphoma.Leukemia & lymphoma 01/2013; · 2.61 Impact Factor