Primary cardiac B cell lymphoma is rare. To date, fewer than 90 cases have been described in the literature. We report a 67-year-old woman with a 30-year history of rheumatoid arthritis, who had received treatment with leflunomide for 10 years and infliximab for 2 years. Secondary Felty's syndrome appeared. She was admitted to the hospital for abdominal pain. Investigations disclosed a 5cm cardiac mass in the right atrium. Histopathologic examination of tissue specimens obtained at surgical myocardial biopsy demonstrated primary cardiac B cell lymphoma. The other iatrogenic lymphoproliferative disorders are reviewed. This lesion might be a manifestation of long term TNFα antagonists treatment.