2019 Volume 61 Issue 12 Pages 2597-2603
A 49-year-old man who was being treated with methotrexate (MTX) for rheumatoid arthritis, was referred to our hospital because his annual screening esophagogastroduodenoscopy showed a small submucosal tumor (SMT)-like lesion in the greater curvature of the lower gastric body. The lesion had grown larger 4 weeks later, and an ulcer had appeared on the lesion by 7 weeks. Based on histology, immunostaining, flow cytometry and his clinical course, we diagnosed MTX-associated diffuse large B-cell lymphoma (DLBCL). As discontinuing use of MTX did not shrink the lesion, we introduced the CHOP regimen. Complete remission (CR) was achieved after 4 courses of CHOP; this CR has continued for 3 years to date. To our knowledge, this is the first report to show endoscopic findings of gastric DLBCL from the initial to moderately advanced stages. This experience suggests that gastric SMT-like lesions in the subepithelial mucosal layer might be early-stage DLBCL. Therefore, such lesions should be carefully diagnosed and followed up, especially in patients treated with MTX.
