A case of gastric plasmacytoma associated with Helicobacter pylori infection: improvement of abnormal endoscopic and EUS findings after H pylori eradication

Plasmacytoma is a tumor derived from plasma cells, the effector cells of th e B lymphoid lineage. Among the extramedullary plasmacytomas, gastric plasm acytoma is rare and constitutes only 5% of these tumors.(1) Recently Kinosh ita et al.(2) described an interesting patient with low-grade gastric mucos a-associated lymphoid tissue (MALT) lymphoma in whom monoclonal immunoglobu lin (Ig) (IgM-lambda) was detected in serum and gastric juice, suggesting a close pathogenic relationship between gastric MALT lymphoma and gastric pl asmacytoma.(2) Although a close causative association between Helicobacter pylori infection and gastric MALT lymphoma has been recognized,(3) to our k nowledge there has been only one report tin Spanish) detailing the relation ship between H pylori and gastric plasmacytoma, which described a gastric p lasmacytoma in a 14-year-old patient with H pylori infection in whom the tu mor regressed after antibiotic therapy.(4) This is the second case report o f gastric plasmacytoma associated with H pylori infection.