Primary Synovial Diffuse Large B-Cell Lymphoma Presenting as Loosening of Prosthetic Joint: A Case Report and Review of Literature

Primary synovial diffuse B-cell lymphoma is a rare clinical condition. The condition presents primarily with localized joint symptoms such as swelling, pain and reduced range of motion. It may or may not be associated with lymphadenopathy, hepatosplenomegaly or B-type constitutional symptoms. We report a case of a 74-year-old woman who presented with persistent left knee pain and swelling after left knee replacement secondary to osteoarthritis. There was a concern for mechanical loosening of internal left knee prosthetic joint. On revision surgery (14 weeks after the initial surgery), hypertrophied synovium with areas of fibrotic scars, necrotic tissue and dark colored masses was resected. She was found to have diffuse large B-cell lymphoma (DLBCL) after histological analysis. In cases with persistent joint symptoms or postoperative complications, arthroscopy or arthrotomy should be considered and any atypical appearing tissue should be sent for histopathological analysis.