Autopsy case of lymphoplasmacytic lymphoma with a large submucosal tumor in the stomach

Disseminated Gastric MALT Lymphoma with Monoclonal Gammopathy, t(11;18)(q21;q21), and Subsequent Development of T-Large Granular Lymphocytic Leukemia: A Case Report and Review of the Literature

Background. Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) is a well-characterized entity that may share clinical and morphological findings with other low-grade non-Hodgkin's lymphomas. Dissemination of MALT-type lymphoma to bone marrow and peripheral blood simultaneously with the presence of T-large granular cell leukemia (T-LGL) has rarely been reported. Case Presentation. This is the case of a 42-year-old male who presented with a gastric MALT-type lymphoma, disseminated to the bone marrow and the peripheral blood with high serum IgM levels and t(11;18)(q21;q21). The morphological, immunophenotypical and, immunohistochemical studies of the successive bone marrow and peripheral blood samples had revealed the coexistence of two distinct lymphoma cell populations: a B-cell, marginal zone type population expressing CD19, CD20, CD22, CD79b, IgM, and kappa light chain, and a T-large granular cell population, developed after treatment with rituximab expressing CD3, CD8, CD5, CD7, and CD45. Conclusion. Based on the analysis of this unusual case we performed an extensive review of the literature to elucidate the relationship between T-LGL and B-cell lymphomas and to emphasize the importance of paraprotein analysis at diagnosis of gastric MALT lymphoma.

Primary submucosal nodular plasmacytoma of the stomach: a poorly recognized variant of gastric lymphoma

Abstract

Gastric plasmacytoma (GP) is a rare variant of gastric lymphomas. In the exceptional event that a patient presents with GP, the lesion occupies the mucosal layer in the vast majority of cases. Here we report a case of nodular plasmacytoma confined to the submucosa with no evidence of Helicobacter pylori (Hp) infection. The patient was a 59-year old female presenting with no particular symptoms. The tumor was well-demarcated and consisted of a diffuse monomorphic proliferation of plasma cells with numerous lymphoid follicles scattered throughout the tumor. The mucosal surface was intact and not associated with any tumor nodules. The cells were diffusely positive for CD79a, Bob1, EMA and IgA and consistently negative for CD3, CD19, CD20, PAX5, CD56, IgM and IgG. Additionally, in situ hybridization demonstrated clonality in the form of λ light-chain restriction. This submucosal nodular proliferation pattern of plasmacytoma is poorly recognized and considered to be a novel variant of lymphoma.

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Gastric MALT Lymphoma Presenting as Waldenström's Macroglobulinemia Without Bone Marrow Involvement

We report a case of gastric mucosa-associated lymphoid tissue (MALT) lymphoma with macroglobulinemia in a 59-year-old man who presented with melena. A computed tomography scan of the abdomen showed irregular thickening of the wall of the stomach, and endoscopic examination disclosed enlarged and inflammatory folds of the fundus. Histopathologic examination of gastric samples showed mucosal infiltration by small lymphocytes, which were positive for CD20 and negative for CD10 and CD23, confirming the diagnosis of gastric MALT lymphoma. Serum electrophoresis detected a monoclonal peak and immunoelectrophoresis revealed an immunoglobulin M kappa component. Bone marrow aspirate and biopsy results were normal. The patient received chemotherapy. After treatment, he was in complete remission, and the serum monoclonal component had disappeared. Our observation is uncommon because of important macroglobulinemia occurring in gastric MALT lymphoma without bone marrow involvement.