Primary low‐grade gastric mucosa‐associated lymphoid tissue (MALT) lymphoma with polypoid appearance. Polypoid gastric MALT lymphoma: A clinicopathologic study of eight cases

Abstract

In the current study, we report eight cases with primary low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma endoscopically characterized by polypoid lesions in order to highlight their clinicopathologic significance. Four patients were male, their ages ranging from 40 to 78 years old. The resected specimens revealed a histology of low-grade MALT lymphoma characterized by dense lymphocytic infiltration predominantly in the submucosa and a relatively monotonous proliferation of centrocyte-like cells with reactive follicles and infrequent lymphoepithelial lesions. The tumor cells were of CD5-, CD10-, CD20+, BCL2+ and cycline D1- phenotype, and showed a monoclonal rearrangement of immunoglobulin heavy chain genes in the five of six cases examined. Interestingly, Helicobacter pylori (H. pylori) was detected in three (37.5%) of the eight patients, which was significantly lower than previous reports. Two of the H. pylori-positive cases initially underwent H. pylori eradication, but showed no change in their lymphomas after the cure of H. pylori infection. The clinicopathologic findings of the present cases appeared to closely resemble those of colorectal MALT lymphoma with a polypoid appearance and few association of H. pylori infection in their pathogenesis. These gastric polypoid cases may merit separate consideration because of the therapeutic problems they pose.

Gastric low-grade B-cell MALT lymphoma: treatment, response, and genetic alteration

“…6). 46 These findings were also seen in three API2-MALT1-negative nonresponders. On the other hand, marked plasmacytoid differentiation of the tumor cells was observed in two API2-MALT1-negative responders, simulating an extramedullary plasmacytoma.…”

Helicobacter pylori and the t(11;18)(q21;q21) Translocation in Gastric Low‐grade B‐Cell Lymphoma of Mucosa‐associated Lymphoid Tissue Type

“…We recently reported 8 cases of polypoid gastric MALT lymphoma, the clinicopathologic features of which appeared to resemble closely those of colorectal MALT lymphoma with a polypoid appearance, with little association of H. pylori infection in the pathogenesis. 21) Indeed, t(11;18)(q21;q21) was also often observed in MALT lymphoma of the colon and lung. 12,22) These data led to the speculation that the polypoid gastric MALT lymphoma separated from H. pyloridependent non-polypoid tumor is closely associated with c-IAP2-MALT1/MLT gene alteration resulting from t(11;18)(q21;21), and should be categorized together with MALT tumor arising in lung, colon and others with this unique chromosomal translocation.…”

Extranodal lymphomas: Review of clinicopathologic and cytologic features

“…Additionally, bleeding and weight loss may be noted. 8 In sites other than the stomach, patients usually present with symptoms related to the presence of a mass lesion, but without systemic symptoms. Site-specific clinical associations are also noted such as gastric marginal zone lymphoma often arises in the setting of Helicobacter pylori gastritis.…”

“…Subsequently, others have also reported a therapeutic response rate ranging from 60 to 90%. 8,12 The time period noted for clinical regression may be prolonged, with a range of 1 to 25 months. 9,12 In patients with failure of antibiotic therapy or relapses following H. pylori eradication, other treatment options such as surgery, radiation, or chemotherapy, may be employed, and a cure can usually be obtained.…”