Associationof primary gastric lymphoma and adenoma

Primary non-Hodgkin's lymphomas of the gastrointestinal tract represent 3-4% of all malignancies arising in the digestive tract. The most commonly involved site is the stomach (60% of cases). Diffuse large B-cell lymphoma is the most common pathological type of gastrointestinal lymphoma. Gastric collision tumors have been rarely reported in the literature. They are most often synchronous incidentally discovered. They can associate benign or malignant epithelial tumors with mesenchymal or lymphomatous tumors. We propose to review the clinicopathological features of gastric collision tumors and the impact of Helicobacter pylori in the genesis of this association. We report the case of an 80 year-old man who had an epigastric pain, a gastroesophageal reflux and alteration of general condition. The endoscopic examination showed a cardialtumoral process associated to an antral polyp. The histological examination of different biopsies done at this process, showed a lymphomatous proliferation made of cells of medium to large size, mainly compounds of immunoblasts and centroblasts. At the immunohistochemical study, tumor cells expressed highly the CD20 which confirmed its B nature. The polyp corresponded to a high grade adenoma. The diagnosis of synchronous diffuse large B cell lymphoma and high grade adenoma involving the stomach was retained. Otherwise, features of chronic atrophic gastritis with intestinal metaplasia were present in this case. These findings, suggest that Helicobacter Pylori infection may have played a major role in the development of these two tumors.