Ruxolitinib for the Treatment of Refractory Idiopathic Multicentric Castleman Disease: A Case Report

To the Editor, A 46-year-old female with a 4-month history of severe fatigue was admitted to our hospital in November 2018.PET/CT revealed hepatosplenomegaly and multiple enlarged lymph nodes with slightly elevated 18 F-fluorodeoxyglucose uptake.Biopsy of the right axillary lymph node was consistent with the plasma cell subtype of Castleman disease (CD), with immunohistochemistry for CD20 (+), CD138 (+), CD3 (+), IgG (+), Kappa (+), Lambda (+), and Ki67 (index = 10%).Laboratory tests showed mild anemia (hemoglobin, 113 g/L), elevated platelet count (406 × 10 9 cells/L), impaired renal function with elevated serum creatine levels (141 μmol/L), elevated C-reactive protein (CRP) levels (69.20 mg/L), and hypergammaglobulinemia (IgG, 30.48 g/L) without monoclonal gammopathy.The serum albumin level was 36 g/L.The human herpes virus-8 (HHV-8)/HIV test results were negative.According to the Castleman Disease Collaborative Network (CDCN) diagnostic criteria [1], she was diagnosed with non-severe idiopathic multicentric CD-not otherwise specified subtype (iMCD-NOS).Siltuximab, the only US Food and Drug Administration (FDA)-approved therapy, was not available in China at the time, and other recommended treatment options for nonsevere iMCD, such as tocilizumab and rituximab, were off-label regimens in China