Composite Lymphoma after Treatment with Infliximab for Sarcoidosis and Ankylosing Spondylitis.

Lymphoid proliferations and lymphomas associated with immune deficiency and dysregulation (LP/L-IDD) are rare entities associated with the use of immunosuppressive drugs (ISD) for autoimmune conditions. Composite lymphomas, featuring both B-cell and T-cell lymphomas, are infrequent, and their occurrence as LP/L-IDD is rare. We herein report the case of a 70-year-old man with right pleural effusion and lymphadenopathy, who was treated with infliximab for sarcoidosis and ankylosing spondylitis. A biopsy revealed a composite lymphoma of DLBCL and PTCL-NOS. CHOP chemotherapy led to significant remission. This case report emphasizes the need to consider lymphoma in patients with autoimmune diseases such as sarcoidosis and ankylosing spondylitis, especially those treated with ISDs.