gastric lymphoma

Primary gastric lymphoma (lymphoma that originates in the stomach itself) is an uncommon condition, accounting for less than 15% of gastric malignancies and about 2% of all lymphomas. However, the stomach is a very common extranodal site for lymphomas (lymphomas originate elsewhere and metastasise to the stomach). It is also the most common source of lymphomas in the gastrointestinal tract. Signs and symptoms Symptoms include epigastric pain, early satiety, fatigue and weight loss. Most people affected by primary gastric lymphoma are over 60 years old. Risk factors Risk factors for gastric lymphoma include the following: Helicobacter pylori Long-term immunosuppressant drug therapy HIV infection Pathophysiology The majority of gastric lymphomas are non-Hodgkin's lymphoma of B-cell origin. These tumors may range from well-differentiated, superficial involvements (MALT) to high-grade, large-cell lymphomas. Sometimes, it's hard to differentiate poorly differentiated high grade B-cell gastric lymphoma from gastric adenocarcinoma clinically or radiologically, yet histopathology with immunohistochemistry is recommended to stain specific markers on the malignant cell that favor the diagnosis of lymphoma. Immunohistochemistry stains specific clusters of differentiation that are present on B-cells like CD20. Cytokeratin is also a surface marker that is presented on epithelial cells, is stained histochemically and favors the diagnosis of epithelial tumors like adenocarcinoma.