Extranodal Manifestation of Rosai-Dorfman Disease Without Involvement of Lymph Nodes

Background: Rosai-Dorfman disease is an uncommon sinus histiocytosis with massive lymphadenopathy. Rosai-Dorfman disease without lymphadenopathy is extremely rare. Extranodal pseudotu-moral masses can occur-and have been identified and described-in the orbit, skin, bone, and upper respiratory tract. Because of its rareness, Rosai-Dorfman is seldom considered in the clinical differential diagnosis, particularly if extranodal manifestations predominate. Methods and Results: We present herein a patient with extranodal manifestation of Rosai-Dorfman disease in the orbit and parotid without typical initial lymph node involvement that reacted on steroid therapy. Conclusions: The correct diagnosis of this entity with the knowledge that it can occur without lymphadenopathy is important. For these patients, diagnosis must be based on histologic and immuno-histopathologic findings after surgical biopsy. Steroid therapy can be used for treatment.