*Department of Internal Medicine, Busan Medical Center, Busan, Korea.
†Department of Internal Medicine, Busan National University School of Medicine, Busan, Korea.
Extramedullary plasmacytoma (EMP) is an uncommon manifestation of plasma cell neplasia, which occurs outside the bone marrow. Intestinal involvement usually occur secondarily in multiple myeloma but it occur primarily less commonly. We experienced a woman who had a primary EMP localized in the stomach and the EMP was removed successfully by endoscopic submucosal dissection. The lesion was pathologically confirmed as confined to the gastric mucosa.