Two Cases of Systemic Lupus Erythematosus With Castleman Disease

Systemic lupus erythematosus is a heterogeneous autoimmune disease that commonly presents with lymphadenopathy, a feature that can lead to confusion with other diseases due to its non-specificity. Histopathological features are usually nonspecific and may mimic other conditions. Other cases have described Castleman disease, a rare lymphoproliferative disorder, in patients with systemic lupus erythematosus. This uncommon association poses diagnostic challenges due to the clinical overlap. We present cases of two Latin-American women with systemic lupus erythematosus and generalized lymphadenopathy, with histopathological findings compatible with plasma cell-subtype Castleman disease, who showed adequate response to rituximab treatment.