A case of Rosai-Dorfman disease with markedly increased level of serum inflammatory markers successfully treated with steroid therapy

Abstract

    A 71-years-old man admitted to our institution because of neck swelling, pain and high fever. Due to elevated level of serum CRP (14.3 mg/dl) and bilateral cervical lymph node enlargement on computed tomography, he was considered to have an infection and treatment with some antibacterial agents was started, however these showed no response. His lymph node biopsy specimen revealed patchy infiltration of histiocytes containing small lymphocytes in an abundant cytoplasm, known as emperipolesis. Immunohistologically, infiltrating histiocytes were positive for S-100 protein and CD68. He was diagnosed with Rosai-Dorfman disease (RDD) from these findings. Furthermore, IgG4 positive plasma cells were occupied about 50% of IgG positive cells in the specimen and serum IgG4 showed high level (160 mg/dl). These findings met the IgG4-related disease (IgG4-RD) classification criteria. After the treatment with prednisolone 40 mg/day, his high level of serum inflammatory markers and lymph node enlargement improved. RDD is a rare histiocytic proliferative disorder of unknown etiology that is clinically characterized by cervical lymphadenopathy, fever, elevated level of serum CRP and erythrocyte sedimentation rate (ESR). Several recent articles reported that RDD could be associated with IgG4-RD because some patients with RDD have increased numbers of IgG4 positive cells and an elevated IgG4/IgG ratio. Our case exhibited features characteristic for IgG4-RD. This indicates that there are some pathological overlaps between these two diseases.