68Ga-FAPI and 18F-FDG PET/CT Images of a Patient With Rosai-Dorfman Disease With Liver Involvement

Abstract Rosai-Dorfman disease is a rare non-Langerhans cell histiocytosis that is histopathologically characterized by the accumulation of CD68-positive and S100-positive histiocytes. The pathological changes are mostly discovered in lymph nodes. We report a case of Rosai-Dorfman disease with liver and bone marrow involvement. In this case, 18 F-FDG PET/CT revealed FDG avidity in multiple lymph nodes, liver, and bone marrow. 68 Ga-FAPI PET/CT showed higher uptake of 68 Ga-FAPI than that of 18 F-FDG in the same lesions. The findings of 68 Ga-FAPI PET/CT in this patient highlighted the potential value of 68 Ga-FAPI for staging in Rosai-Dorfman disease.