Novel developments in the pathogenesis and diagnosis of extranodal marginal zone lymphoma

Abstract

Extranodal marginal zone lymphoma (EMZL), mostly represented by mucosa-associated lymphoid tissue (MALT) type, also referred to as MALT lymphoma, is a clinically heterogeneous entity within the group of low-grade B cell lymphomas that arises in a wide range of different extranodal sites, including the stomach, lung, ocular adnexa, and skin. It represents the third most common non-Hodgkin lymphoma in the Western world, and the median age of occurrence is around 60 years. One characteristic aspect in a subset of EMZL detectable in about 25% of the cases is the presence of specific chromosomal translocations involving the genes MALT1 and BCL10, which lead to activation of the NF-κB signaling pathway. Another unique aspect is that several infectious agents, such as Helicobacter pylori in the case of gastric EMZL, and autoimmune disorders, like Sjögren syndrome, have been implicated in the pathogenesis of this cancer. Recent findings as summarized in this review have further improved our understanding of the complex pathobiology of this disease and have been essential to better define novel treatment strategies. In addition, many of these specific features are currently being implemented for the diagnosis of EMZL.

Diffuse large B cell lymphoma in a preceding IgG4-related disease with kidney restricted lambda light chain expression: case report and literature review

“…As we all know, the diagnosis of EMZL can be rather challenging, as extranodal sites of disease are sometimes difficult to access, resulting in the limitation of small biopsy samples. The optimal diagnosis of EMZL requires integration of clinical, histopathological, and molecular information [16].…”

“…It could establish an environment fertile to lymphoma development in both nodal and extranodal sites especially EMZL [17,18]. The chronic inflammation might be induced by bacteria, virus or various autoimmune diseases including IgG4-RD [8,[16][17][18][19][20][21][22][23]. We have known that there is fibroinflammatory condition in IgG4-RD.…”

Association between Helicobacter pylori infection and Sjögren syndrome

“…[23] As is well known, gastric MALT lymphoma is strongly correlated with H. pylori infection, [24] and eradication therapy will induce regression of the lymphoma. [25] Although the MALT lymphoma along with SS was mainly found in silvery glands [26] as a result of routine salivary glands biopsy for diagnosis according to the SS classification criteria, [27] regression of lymphoma was actually found after these patients with SS with gastric H. pylori infection received eradication therapy in some case reports. [28,29] Based on the results of our above study, it is likely that H. pylori infection would be a risk factor of SS-associated MALT lymphoma.…”

Lung complications of Sjogren syndrome

“…Primary lymphoma of the lung is a rare entity representing about 4% of all extranodal lymphomas and 0.4% of non-Hodgkin lymphomas [111]. The prevalence of primary pulmonary lymphoma seems to be higher in pSS patients and it is estimated to be 1-2% [112]; it is usually a low-grade extranodal marginal B-cell lymphoma of the MALT type and rarely associated with an infectious agent, such as human herpesvirus-6 or Epstein-Barr virus [112].…”