Rosai and Dorfman first described sinus histiocytosis with massive lymphadenopathy in 1969 as a benign lymphohistiocytic proliferative condition involving lymph nodes. The classic clinical presentation of Rosai-Dorfman disease is massive painless cervical lymphadenopathy, but can also include nasal obstruction, tonsillar enlargement, or hearing abnormalities. It and may be accompanied by leukocytosis, elevated erythrocyte sedimentation rate (ESR), weight loss, and hypergammaglobulinemia. While lymph node involvement often dominates the clinical presentation, other anatomic sites are involved in 30-40% of cases, most commonly the skin, upper respiratory tract, orbit and testes. It is understandable why PET is sometimes viewed as an appropriate screening modality.
However, FDG is not a tumor-specific tracer, and numerous nonmalignant processes can result in increased FDG accumulation. Its utility in managing Rosai-Dorfman disease is not well supported by the literature. Because of the rarity of the disease, available information is restricted to case reports of use.
Treatment is not necessary in most instances, but some patients may require surgery, radiation therapy, and/or chemotherapy because of severe disease manifestations. As such, a screening PET is unlikely to provide iformation that would lead to treatment. An ideal treatment has yet to be identified.
Ruth Lim et al, FDG PET of Rosai-Dorfman Disease of the Thymus AJR 2004; 182:514
Menzel C, Hamscho N, Döbert N, Grünwald F, Kovács AF, Wolter M, Podda M.PET imaging of Rosai-Dorfman disease: correlation with histopathology and ex-vivo beta-imaging.Arch Dermatol Res. 2003 Dec;295(7):280-3.