Gastric Perforation due to Iatrogenic Immunodeficiency-associated Lymphoproliferative Disorder during the Treatment of Rheumatoid Arthritis.

A 71-year-old woman being treated with methotrexate (MTX) and tacrolimus (TAC) for rheumatoid arthritis (RA) was admitted to our hospital and underwent surgery for gastric perforation and peritonitis. An endoscopic examination six days post-surgery showed an extensive ulcer in the stomach, and a biopsy revealed diffused large B-cell lymphoma. We diagnosed her with immunodeficiency-associated lymphoproliferative disorder (LPD) and discontinued the MTX and TAC. She underwent gastrectomy due to stenosis approximately two months after the first operation, but the histopathological findings of lymphoma had disappeared. LPD should be considered as a potential cause of gastric perforation during RA treatment.