ABSTRACT
INTRODUCTION: Castleman disease is a rare lymphoproliferation, which may mimic systemic lupus. Conversely, systemic lupus sometimes presents like an hematological malignancy. In these cases, a "Castleman-like" histology has been exceptionally described. OBSERVATION: A 55-year-old female treated by methotrexate for systemic lupus with skin and joint involvement presented weight loss, polyadenopathy and clinical signs of lupus flare. Biology showed pancytopenia, complement activation, and positive anti-DNA antibodies. PET/CT showed hypermetabolic polyadenopathy. The lymph node biopsy showed "Castleman-like" features. Treatment with corticosteroids and azathioprine resulted in complete remission. CONCLUSION: Systemic lupus and Castleman disease may share common clinical, biological, and histological features. The presence of specific elements of systemic lupus flare and the remission obtained by low-dose corticosteroids results in considering the diagnosis of Castleman-like systemic lupus and avoiding treatment intensification.
