原発性シェーグレン症候群における低悪性度B細胞リンパ腫：症例報告

Primary Sjögren's syndrome (pSS) is associated with an increased risk of lymphoproliferative disorders, including non-Hodgkin lymphoma (NHL). We report the vase of a woman with longstanding pSS who presented with progressive weight loss, massive splenomegaly, and cytopenias. Extensive hepatologic evaluation, including transjugular liver biopsy, showed no evidence of cirrhosis or intrinsic liver disease. Bone marrow biopsy established the diagnosis of a low-grade B-cell lymphoma consistent with marginal zone lymphoma. The patient was treated with rituximab monotherapy and demonstrated a good clinical response. This case underscores the importance of maintaining a high index of suspicion for lymphoproliferative disease in pSS patients who develop unexplained splenomegaly and cytopenias, even in the absence of lymphadenopathy or classic B symptoms. When hematologic abnormalities persist despite negative preliminary investigations, bone marrow biopsy remains essential for timely and definitive diagnosis.