Successful tocilizumab monotherapy for multicentric Castleman disease complicated by rheumatoid arthritis and Sjögren's disease: a case-based literature review.

Multicentric Castleman disease (MCD) is a rare and complex lymphoproliferative disorder marked by multiple lymph node enlargement, characteristic histopathological features, and systemic inflammation driven by excessive interleukin-6 (IL-6) production. MCD can occasionally coexist with other autoimmune diseases, but the therapeutic approach in such cases remains poorly defined. Here, we present the first documented case of MCD complicated by both rheumatoid arthritis (RA) and Sjögren's disease (SjD), where all conditions were successfully treated with tocilizumab (TCZ) monotherapy, an IL-6 receptor antagonist. Furthermore, a literature review identified two previously reported cases of MCD with either RA or SjD, all of which showed favorable responses to TCZ. Our findings highlight the potential of TCZ as an effective therapeutic option for patients with MCD in the context of coexisting autoimmune disorders, offering new hope for managing these challenging clinical scenarios.